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Ch26 / Ch620

1. 35 955 35 973 mm 1 4156 1 4163 in OTD IMAG VV bii 35 94 mm 1 415 in as petro a 0 018 mm 0 0007 in Max Outo eI TORNEO 0 025 mm 0 0010 in Section 1 Safety and General Information Crankshaft cont Crankshaft T I R PIO ERG Cani T5 EDS INE perme tree errr en ere Tne Tre fetu sn Terre Un CR E ener 0 279 mm 0 0110 in Entire Crank gm V BlOCK cia cere ceca demuscincnalacacira sete utr AEE 0 10 mm 0 0039 in Cylinder Bore Cylinder Bore LD New CH18 CH620 CH20 CH640 CH22 624 QC eesucnessubewenseus nude sabes aatua vu ete ap hs oe ns 77 000 77 025 mm 3 0315 3 0325 in CH22 C H670 CES E 1080 674 OC cosssansibunuset die EUR UUN Uo UE SURE aie 80 000 80 025 mm 3 1496 3 1506 in CH25 CH26 CH735 CH730 CH740 CH745 CHX750 eerte 82 988 83 013 mm 3 2672 3 2682 in Max Wear Limit CH18 CH620 CH20 CH640 CH22 624 cc 77 063 mm 3 0340 in Max Wear Limit CH22 CH670 CH23 CH680 674 cc sess 80 065 mm 3 1522 in Max Wear Limit CH25 CH26 CH735 CH730 CH740 CH745 CH750 83 051 mm 3 2697 in Max COU FO OUNCE saines n A a ERER Ean R 0 12 mm 0 0047 in A ro Mio E A E A A A E E E 0 05 mm 0 0020 in Cylinder Head Cylinder Head Fastener Torque Hex Flange Nut Torque in Two Stages eseseeeessesrrseseererrereerereererserreeerses first to 16 9 N m 150 in Ib finally to 33 9 N
2. 16 995 17 000 mm 0 6691 0 6693 in Max Wear GIMMIE ROREM 16 994 mm 0 6691 in Top Compression Ring to Groove Side Clearance CHIS CHO2OC HZ0 CHAO E H22 024 GC jiener 0 040 0 080 mm 0 0016 0 0031 in CEHZ2CTIO70 C EI2SIC H690 674 CC ristien aaen 0 030 0 076 mm 0 0012 0 0030 in CH25 CH26 CH733 CH730 C H740 CEPAES CTDEUZOU aestatis rte reer 0 025 0 048 mm 0 0010 0 0019 in Middle Compression Ring to Groove Side Clearance CH16 CH620 C E20 C H640 C E122 02 CC snisnsienisnasnassnsnsspvonsasbaaebcsnsbsobesuns 0 040 0 080 mm 0 0016 0 0031 in CHACHO OCT RICHOU Dd nee emer nan tren etree dede 0 030 0 076 mm 0 0012 0 0030 in CEDSCH2S GEHZS5 CHZ90 C HZ40 C745 C750 s iapeens dest puso ede opus ens 0 015 0 037 mm 0 0006 0 0015 in Oil Control Ring to Groove Side Clearance CBISCTHO20 C EI20 CH640 CH22 024CC iusnassensuentedidecte doct uquutendroaebu dus 0 060 0 202 mm 0 0024 0 0080 in CEHZ2ZICHOZ0 CEI2SIC H690 074 CO oss cn saschcatvtes eid Eaki eee 0 046 0 196 mm 0 0018 0 0077 in CH25 CH26 CH735 CH730 CH740 CH745 CH750 sseseesesesersrseserererses 0 026 0 176 mm 0 0010 0 0070 in Section 1 Safety and General Information Piston Piston Rings and Piston Pin cont Top and Center Compression Ring End Gap New Bore CH18 CH620 CH20 CH640 CH22 02 4 06 eeeeiteeesn aide boss pusci babet eos ib nd6e 0 25 0 45 mm 0 0098 0 0177 in CH22 CH670 CH23 CH680 674 CO sscstesecsatsotssressecderanteetossonesa
3. 0 070 0 590 mm 0 0028 0 0230 in End Play With Thrust Bearing Components sssissiessissssirisesssessssessesisisissrsvisssss 0 070 0 270 mm 0 0028 0 0100 in Except CH25 Engines Below Serial No 2403500008 sess 0 050 0 750 mm 0 0020 0 0295 in Crankshaft Bore In Crankcase Mo N 40 965 41 003 mm 1 6128 1 6143 in Max Wear CIT rH 41 016 mm 1 6148 in Crankshaft to Sleeve Bearing Crankcase Ronne C Tear NOW encrier R EE rrr 0 03 0 09 mm 0 0012 0 0035 in Crankshaft Bore In Closure Plate NeW iccsssesaccssaccscncvesecdesatuasdevasiecatsesncansnteeanios 40 987 40 974 mm 1 6136 1 6131 in Crankshaft Bore In Closure Plate to Crankshaft Wt eC Near NEW d 0 039 0 074 mm 0 0015 0 0029 in Flywheel End Main Bearing Journal QURE I 40 913 40 935 mm 1 6107 1 6116 in OD Max T aliii m TM 40 84 mm 1 608 in M LP M 0 022 mm 0 0009 in INT ENG CTO ls OU ING seisena EE hd ba iniu d co dd e 0 025 mm 0 0010 in Closure Plate End Main Bearing Journal OARRA 40 913 40 935 mm 1 6107 1 6116 in UD IMA Wear LIOI Decii a a 40 84 mm 1 608 in M loli a E 0 022 mm 0 0009 in Max Outo KOUD srera a a E E R IU MU Da E qu a QUOI Es 0 025 mm 0 0010 in Connecting Rod Journal OBEE a
4. 2 Start the engine and allow it to fully warm up and establish closed looped operation approximately 5 10 min 3 Place the throttle control in the idle slow position and check the idle speed with a tachometer Turn the idle speed screw in or out as required to obtain 1500 RPM or the idle speed specified by the equipment manufacturer 4 Thelow idle speed adjustment can affect the high speed setting Move the throttle control to the full throttle position and check the high speed Adjust as necessary to 3750 RPM no load or the speed specified by the equipment manufacturer Idle Speed Screw Dampening Spring A small dampening spring Kohler Part No 24 089 42 S is attached to the end of the idle speed screw of some EFI engines to help stabilize no load operating speeds See Figure 5B 36 oB 23 Section 5B EFI Fuel System 1 3 mm 0 039 0 117 in Exposed Length Off End Of Adjustment Screw Dampening Spring Some Models Idle Speed Screw Figure 5B 36 Idle Speed Screw Details The idle speed adjustment procedure remains the same for engines with or without a dampening spring Typically no periodic servicing is necessary in this area If however removal replacement of the dampening spring is required reinstall it as follows 1 Thread the spring onto the end of idle screw leaving 1 3 mm 0 039 0 117 in of the spring extending beyond the end of the idle speed screw 2 Secure spring onto the scr
5. 3 Check alignment of bracket and torque the valve cover screws as prescribed in Install Valve Covers Torque the upper mounting screws into the manifold two barrel models only to 9 9 N m 88 in Ib 4 Connect the air cleaner hose to elbow or adapter e on carburetor and secure with a clamp Installand Figure 11 99 Torquing Oil Filter Nipple Crankcase tighten hood onto the air cleaner inlet See Figure Mounted Cooler 11 98 11 29 Section 11 Reassembly asic re HEELE CE E EP ee re ee ee Be Er N Mounting Locations d Figure 11 100 Mounting Oil Cooler Blower Housing Mounted Cooler Install Oil Filter and Fill Crankcase with Oil 1 Prefill a new oil filter following the instructions in Section 6 2 Apply a thin film of clean engine oil to the rubber gasket on the oil filter and thread the filter onto the adapter nipple See Figure 11 101 Figure 11 101 Installing New Oil Filter 3 Install the new oil filter to the filter adapter or oil cooler Refer to instructions on the oil filter for proper installation 11 30 Figure 11 102 Install Oil Filter 4 Install the oil drain plugs See Figure 11 103 Torque the plugs to 13 6 N m 10 ft Ib NOTE Make sure that both oil drain plugs are installed and torqued to the above specifications to prevent oil leakage Figure 11 103 Reinstall and Torque Both Oil Drain Plugs 5 Add oil to bring the level up to F mark and reinsta
6. B Capacitive Discharge with Electronic Spark Advance SMART SPARK SMART SPARK equipped engines utilize an electronic capacitive discharge ignition system with electronic spark advance A typical application Figure 8 6 consists of the following components A magnet assembly which is permanently affixed to the flywheel Two electronic capacitive discharge ignition modules which mount on the engine crankcase Figure 8 6 A spark advance module which mounts to the engine shrouding Figure 8 7 A 12 volt battery which supplies current to the spark advance module A kill switch or key switch which grounds the spark advance module to stop the engine Two spark plugs Key Switch or Off Position of Key Switch White Spark Plug NS 0 28 0 33 mm 0 011 0 013 in Air Gap Section 8 Electrical System and Components Green Spark Advance Module il Spark Plug P MN TU 2 U j K Module Flywheel Magnet Figure 8 6 Capacitive Discharge Ignition System with Spark Advance The timing of the spark is controlled by the location of the flywheel magnet group as referenced to the engine top dead center and the delay created by the spark advance module Input Coil V 7 2V From Brown Conditioning 7 Delay Circuit Circuit Circuit To Comparator Generator O Semi Conductor Switch Figure 8 7 Block Diagram Spark Advance Module Operation The ignition module f
7. Choke Shaft opring Bushing Choke Lever Choke Plate Choke Plate Screw 2 Governor General The governor is designed to hold the engine speed constant under changing load conditions Most engines are equipped with a centrifugal flyweight mechanical governor Some engines utilize an optional electronic governor which is shown and covered on page 5 23 5 24 The governor gear flyweight mechanism of the mechanical governor is mounted inside the crankcase and is driven off the gear on the camshaft This governor design works as follows e Centrifugal force acting on the rotating governor gear assembly causes the flyweights to move outward as speed increases Governor spring tension moves them inward as speed decreases Governor Spring i Governor Arm Throttle Linkage Figure 5 38 Governor Linkage e As the flyweights move outward they cause the regulating pin to move outward e The regulating pin contacts the tab on the cross shaft causing the shaft to rotate e One end of the cross shaft protrudes through the crankcase The rotating action of the cross shaft is transmitted to the throttle lever of the carburetor through the external throttle linkage See Figure 5 38 e When the engine is at rest and the throttle is in the fast position the tension of the governor spring holds the throttle plate open When the engine is operating the governor gear assembly is rotating The force applied by
8. PH 0 030 0 055 mm 0 0012 0 0022 in hup i iM Eier OE 0 070 mm 0 0028 in Connecting Rod to Crankpin Side C IGaTatiCO Lai eio ire senis eintidur dra od edes EUbhUdd 0 26 0 63 mm 0 0102 0 0248 in Connecting Rod to Piston Pin Running Clearance sss 0 015 0 028 mm 0 0006 0 0011 in Piston Pin End I D hino m m 17 015 17 023 mm 0 6699 0 6702 in IE VVC MST eee ace mue A estis stus Ia EEUU A E E RUNE Fin MUSEI UNE QUT Uses bU ER EOSU S 17 036 mm 0 6707 in Values are in Metric units Values in parentheses are English equivalents Lubricate threads with engine oil prior to assembly 1 9 Section 1 Safety and General Information Crankcase Governor Cross Shaft Bore I D 6 mm Shaft i Mo 6 025 6 050 mm 0 2372 0 2382 in Max Wear Croit RI 6 063 mm 0 2387 in 8 mm Shaft ho 8 025 8 075 mm 0 3159 0 3179 in IIS VWOOE DILE ss hoc atieessg ecto car unas tasa AEE dunes EU Mu Remb eo due enc db dE 8 088 mm 0 3184 in breater Cover P aS EHI TORQUOLaocciasaso uenis natav es nid in M acd dtu URL O Edu dUDPNE headers 7 3 N m 65 in Ib EB t Mp MEOS ET 0 crete rere ire S 13 6 N m 10 ft Ib Closure Plate Closure Plate Fastener FOEQUIO Losses beiden et hated entieirar irin 24 4 N m 216 in Ib Crankshaft SOALE dui MT
9. Mo Fasteners NOT UG rsson ri aa unes ra ar aE 10 7 N m 95 in Ib into new holes 7 3 N m 65 in Ib into used holes ROC GT CoA Fastener TOPOHE n eqcsrasai torso Uqot iind t QU debt n ENERO ERN teT aU Ub US 1 4 N m 12 6 in Ib Camshaft Ead Play VN A UNI NE TT T ES 0 076 0 127 mm 0 0030 0 0050 in Running CRANE RERUM 0 025 0 063 mm 0 0010 0 0025 in Bore I D lc A EEA EE E A A E A E E 20 000 20 025 mm 0 7874 0 7884 in Maxe Wear LUIE C 20 038 mm 0 7889 in Camshaft Bearing Surface O D INV AEE E E E E N A A E E E 19 962 19 975 mm 0 7859 0 7864 in Max Wear iai REEL E 19 959 mm 0 7858 in Carburetor and Intake Manifold Intake Manifold Mounting Fastener Torque TOGA S TWO OE ODE NA E A A N RM DNiNNE first to 7 4 N m 66 in Ib finally to 9 9 N m 88 in Ib Carburetor Mounting Screw TOFOHO TIO qossnsoutcatskidintistr nitide eis E ai RU EpL tM OP EpE LUE 6 2 7 3 N m 55 65 in Ib Adapter for Heavy Duty Air Cleaner Mounting Fastener Torque 7 3 N m 65 in Ib Connecting Rod Cap Fastener Torque torque in increments S Imi SE DE SI cesses ene ue te serdar esrb E pei lacinia iM Doo bn dU mE Reus 22 7 N m 200 in Ib TUPI SES 53 n OE RET m E E E 14 7 N m 130 in Ib bo leche eel es DE SBODIS oca edicit ue HM bU rM a Ur etme ere e nUUM NUS IN RUFUS eT rae 11 3 N m 100 in Ib Connecting Rod to Crankpin Running Clearance Dno
10. A commutator end caps it will be aligned with a premarked line on the starter frame The frame is not premarked on starters with Style B end caps Place a piece of masking tape on the frame and mark a line on the tape in line with the raised line on the end cap See Figure 8 45 Remove the thru bolts Remove the commutator end cap with brushes and brush springs Style A Style B end caps remove as a separate piece with the brushes and carrier remaining in the frame Remove the drive end cap Remove the armature and thrust washer if so equipped from inside the starter frame Remove the brush carrier assembly from the frame Style B starters Style A End Cap Brush Replacement 1 Remove the brush springs from the pockets in the brush holder See Figure 8 43 Remove the self tapping screws negative brushes and plastic brush holder Remove the hex flange nut and fiber washer from the stud terminal Remove the stud terminal with the positive brushes and plastic insulating bushing from the end cap Install the insulating bushing on the stud terminal of the new positive brushes Install the stud terminal into the commutator end cap Secure the stud with the fiber washer and hex flange screw Install the brush holder new negative brushes and self tapping screws Install the brush springs and brushes into the pockets in brush holder Make sure the chamfered sides of the bru
11. Check how the end of the throttle linkage aligns with the bushing hole in the governor lever See Figure 5B 40 It should fall in the center of the hole If it doesn t perform the adjustment procedure as follows igure 5B 40 Throttle Link in Center of Hole Figure 5B 41 Checking Split of Clamp 2 Follow the instructions in Step 2 of Checking the Initial Adjustment then reattach the throttle linkage to the governor lever with the bushing clip It is not necessary to reattach the damper or governor springs at this time Insert a nail into the hole in the top of the cross shaft Using light pressure rotate the governor shaft counterclockwise as far as it will turn then torque the hex nut on the clamping screw to 6 8 N m 60 in Ib See Figure 5B 42 Make sure that the governor arm has not twisted up or down after the nut has been tightened Figure 5B 42 Adjusting Governor Shaft 9B 25 Section 5B EFI Fuel System 4 Verify that the governor has been set correctly With the linkage still retained in the Full Throttle position Step 2 unsnap the bushing clip separate the linkage from the bushing and remove the bushing from the lever Follow Steps 3 and 4 in Checking the Initial Adjustment 5 Reconnect the dampening spring into its governor lever hole from the bottom Reinstall the bushing and reattach the throttle linkage See Figure 5B 37 Reattach the governor spring in the marked hole
12. Drive Service 1 Remove the starter from the engine and remove the dust cover 2 Hold the drive pinion in a vice with soft jaws when removing or installing the stop nut The armature will rotate with the nut until the drive pinion stops against internal spacers NOTE Do not overtighten the vise as this can distort the drive pinion 3 Remove the stop nut stop gear spacer anti drift spring dust cover spacer and drive pinion 4 Clean the splines on drive shaft thoroughly with solvent Dry the splines thoroughly 5 Apply a small amount of Kohler electric starter drive lubricant see Section 2 to the splines The use of other lubricants may cause the drive pinion to stick or bind 6 Apply a small amount of Loctite No 271 to the stop nut threads Style A Style B Figure 8 38 Inertia Drive Electric Starter 8 30 Section 8 Electrical System and Components Style B Drive Service 1 The rubber dust cover has a molded lip on the inside that snaps into a groove in the dust cover spacer see Figure 8 39 Turn the drive pinion clockwise until it reaches the fully extended position While holding it in the extended position grasp the tip of the dust cover with a pliers or vise grip and pull it free from the spacer Dust Cover gt Pm u Figure 8 40 Assembling Inner Half of Tool Around e Retaining Armature Shaft and Retaining Ring Spring Retainer Ring 5 Thread the center screw into
13. MA 1 7 Metal Cased ECU Check the resistance between the relay terminal 87 and pin 35 in main connector Resistance should be 4 15 Q 24 Pin MSE 1 0 Plastic Cased ECU Check the resistance between relay terminal 87 and pin 16 in main connector Then check resistance between relay terminal 87 and pin 17 Resistance should be 4 15 Q for each circuit 32 Pin MSE 1 1 Plastic Cased ECU Check the resistance between relay terminal 87 and pin 14 in the main connector Then check the resistance between relay terminal 87 and pin 15 Resistance should be 4 15 Q for each circuit Check all electrical connections connectors and wiring harness leads if resistance is incorrect Injector leakage is very unlikely but in those rare instances it can be internal past the tip of the valve needle or external weeping around the injector body See Figure 5B 21 The loss of system pressure from the leakage can cause hot restart problems and longer cranking times To check for leakage it will be necessary to remove the blower housing which may involve removing the engine from the unit Check For Leaks Figure 5B 21 Injector Inspection Points 1 Engine must be cool Depressurize fuel system through test valve in fuel rail 2 Disconnect spark plug leads from spark plugs 3 Remove the air cleaner outer cover inner wing nut element cover and air cleaner element precleaner Service air cleaner components as re
14. MSE 1 1 Plastic Cased ECU only Source TPS Auto Learn initialization function failed throttle angle out of learning range Explanation While performing the TPS Auto Learn function the measured throttle angle was not within acceptable limits Expected Engine Response MIL illuminated Engine will continue to run but not properly Upon restart TPS Auto Learn function will run again unless voltage to ECU disconnected to clear memory Possible Causes 1 TPS Related a TPS rotated on throttle shaft assembly beyond allowable range b TPS bad 2 Engine Wiring Harness Related a Broken or shorted wire in harness ECU pin 18 to TPS pin 1 ECU pin 4 to TPS pin 2 ECU pin 8 to TPS pin 3 3 Throttle Body Related a Throttle shaft inside TPS worn broken or damaged b Throttle plate loose or misaligned c Throttle plate bent or damaged allowing extra airflow past or restricting movement 4 ECU Related a Circuit providing voltage or ground to TPS damaged b TPS signal input circuit damaged 5B 41 Section 5B EFI Fuel System 5 Oxygen Sensor Harness Related a Oxygen sensor bad b Wiring problem to oxygen sensor c Muffler leak causing O sensor to falsely indicate a lean condition d Bad ground between ECU and engine Code 51 32 Pin MSE 1 1 Plastic Cased ECU only Source Injector 1 circuit open shorted to ground or shorted to battery Explanation Injector 1 is no
15. MSE 1 1 Plastic Cased ECU only 5B 45 Section 5B EFI Fuel System Diagnostic Aid 4 SPEED SENSOR MIL does not turn off during cranking Indicates the ECU is not receiving a signal from the speed sensor Possible causes 1 Speed sensor 2 Speed sensor circuit problem 35 Pin MA 1 7 Metal Cased ECU Pin circuits 3 and 21 24 Pin MSE 1 0 Plastic Cased ECU Pin circuits 9 and 10 32 Pin MSE 1 1 Plastic Cased ECU Pin circuits 9 and 10 3 Speed sensor toothed wheel air gap 4 Toothed wheel 5 Flywheel key sheared 6 ECU Diagnostic Aid 5 FUEL PUMP fuel pump not turning on Possible causes 1 Fuel pump fuse 2 Fuel pump circuit problem 35 Pin MA 1 7 Metal Cased ECU Circuits 43 44 and relay 24 Pin MSE 1 0 Plastic Cased ECU Circuits 30 87 and relay 32 Pin MSE 1 1 Plastic Cased ECU Circuits 30 87 and relay 3 Fuel pump Diagnostic Aid 6 RELAY relay not operating Possible causes 1 Safety switches circuit s problem 35 Pin MA 1 7 Metal Cased ECU Circuits 41 and 41A 24 Pin MSE 1 0 Plastic Cased ECU Circuit 3 32 Pin MSE 1 1 Plastic Cased ECU Circuit 25 2 Relay circuit s problem 35 Pin MA 1 7 Metal Cased ECU Circuits 28 41 and 41A 24 Pin MSE 1 0 Plastic Cased ECU Circuits 18 85 30 and 87 32 Pin MSE 1 1 Plastic Cased ECU Circuits 28 85 30 and 87 3 Relay 4 ECU gr
16. mola i E i aum YORUB i i E J i i m A f 3 mE NE 1H p t i jeoymAl 4 is HUM pay i z uoniubI poy r 1 eds yews ll FE n dH Sz zz plousios anig 19BBj4 T t 1 que I k H I A mom eu ATT TALI t 4 ll 4 sAnebeN JOT i Mens A MOjIS9A Maneg pjojiueyw exe1uj g i j e nisod 3 4 5 ERO 410199uuo023 E sapul o Li Snid x1eds ojeubew W bo 660 SZ HOM o 49juOy 1Ing 01 3no e LO SSL 8p 10j2euuo2 SIIM MOJA N S SUM aM poH ms peu enig 14617 eyoueu Aur oued uARUSS HO YONG aunsseld IO Figure 8 24 Wiring Diagram 15 20 25 Amp Regulated Battery Charging System with Smart Spark 8 20 Section 8 Electrical System and Components Figure 8 25 Wiring Diagram 15 20 25 Amp Regulated Battery Charging System with DSAI Ignition and Key Switch 8 21 Section 8 Electrical System and Components 3 Amp Unregulated Charging System Ground To Kill Lead White Ignition Modules LA Spark Spark T Plug Plug v LU 1 Black Key Switch Optional l i 3 Amp 70 Watt Fuse UN Flywheel Optional Yellow ywheel Stator i Oil Sentry Optional i Switch Ammeter X Indicator Light Optional Oil Sentry Switch Shutdown L 12 V Battery Lighting Lead Yellow Diode Charging Lead Black Figure 8 27 3 Amp 70 Watt Stator Stator The stator is mounted on the crankcase behind the fly
17. over the new diameter Section 1 The corresponding oversize Kohler replacement piston will then fit correctly 3 When the bore is within 0 064 mm 0 0025 in of the desired size remove the coarse stones and replace them with burnishing stones Continue with the burnishing stones until the bore is within 0 013 mm 0 0005 in of the desired size and then use finish stones 220 280 grit and polish the bore to its final size A crosshatch should be observed if honing is done correctly The crosshatch should intersect at approximately 23 33 off the horizontal Too flat an angle could cause the rings to skip and wear excessively and too steep an angle will result in high oil consumption See Figure 10 3 e N T X uo EAS No Ne Figure 10 3 Cylinder Bore Crosshatch after Honing 4 After resizing check the bore for roundness taper and size Use an inside micrometer telescoping gauge or bore gauge to take measurements The measurements should be taken at three locations in the cylinder at the top middle and bottom Two measurements should be taken perpendicular to each other at each of the three locations Clean Cylinder Bore After Honing Proper cleaning of the cylinder walls following boring and or honing is very critical to a successful overhaul Machining grit left in the cylinder bore can destroy an engine in less than one hour of operation after a rebuild 10 3 Section 10 Inspection and Re
18. 2 Loosen the hex nut holding the governor lever to the cross shaft 3 Move the governor lever toward the carburetor as far as it will move wide open throttle and hold in this position 4 Insert a nail into the hole on the cross shaft and rotate the shaft counterclockwise as far as it will turn then tighten hex nut securely 5 21 Section 5 Fuel System and Governor Sensitivity Adjustment Governor sensitivity is adjusted by repositioning the governor spring in the holes of the governor lever If speed surging occurs with a change in engine load the governor is set too sensitive If a big drop in speed occurs when normal load is applied the governor should be set for greater sensitivity See Figure 5 39 and adjust as follows 1 To increase the sensitivity move the spring closer to the governor cross shaft 2 To decrease the sensitivity move the spring away from the governor cross shaft ea Governor Lever Figure 5 39 Governor Sensitivity Adjustments Left Side Pull High Speed RPM Adjustment Refer to Figure 5 40 1 With the engine running move the throttle control to fast Use a tachometer to check the RPM speed 2 Loosen the lock nut on high speed adjusting screw Turn the screw outward to decrease or inward to increase the RPM speed Check RPM with a tachometer 3 When the desired RPM speed is obtained retighten the lock nut NOTE When the throttle and choke control cables are
19. 242 to the screw threads M6 and torque to 9 9 N m 88 in Ib Torque the plastic screen mounting screws MA to 2 2 N m 20 in Ib Figure 11 69 Connecting Ground Lead 2 Install the B terminal lead into the center position of the rectifier regulator plug and connect the plug to the rectifier regulator See Figures 11 70 and 11 71 N Figure 11 67 Installing Metal Type Grass Screen 11 19 Section 11 Reassembly E a Grounding 3 i 2 Bracket Figure 11 71 Grounding Bracket and Attached Connector SMART SPARK Module 1 On engines with SMART SPARK reinstall the SAM module to the blower housing or cylinder baffle Do not overtighten the retaining screws See Figure 11 72 11 20 Er S uff Blower Housing Mounting Location Figure 11 72 Reinstalling SAM Module Install Electric Starter Motor 1 Install the starter motor using the two hex flange screws See Figure 11 73 Some inertia drive starters have a pinion cover and spacers on the starter bolts 2 Torque the two hex flange screws to 15 3 N m 135 in Ib Figure 11 73 Installing Electric Starter Motor Section 11 Reassembly 3 On models with a solenoid shift starter connect the leads to the solenoid See Figure 11 74 Figure 11 74 Connecting Leads to Starting Motor NOTE If the engine uses a side mount muffler on the starter side be sure to tie the wires close to the starter to avoid contact
20. 32 Pin MSE 1 1 Plastic Cased ECU only Possible causes 13 Code 55 MIL Light 32 Pin MSE 1 1 Plastic 1 Battery Cased ECU only 2 Main system fuse 14 Code 56 Pump Relay 32 Pin MSE 1 1 Plastic 3 MIL light bulb burned out Cased ECU only 4 MIL electrical circuit problem 15 Code 61 End of Fault Blink Code Transmission 35 Pin MA 1 7 Metal Cased ECU Pin circuits 31 and 31A Diagnostic Aid 3 RUN ON MIL remains on 24 Pin MSE 1 0 Plastic Cased ECU Pin while engine is running circuits 19 and 84 32 Pin MSE 1 1 Plastic Cased ECU Pin Possible causes circuits 29 and 84 1 Fault codes which turn on MIL when engine is 5 Ignition switch running 6 Permanent ECU power circuit problem a Code 21 Engine Speed Synchronization 35 Pin MA 1 7 Metal Cased ECU Pin circuit b Code 22 Throttle Position Sensor TPS 16 c Code 23 Engine Control Unit ECU 24 Pin MSE 1 0 Plastic Cased ECU Pin d Code 31 Oxygen Sensor shorted circuit 1 e Code 34 Fuel System permanent adaptation 32 Pin MSE 1 1 Plastic Cased ECU Pin at limit circuit 1 f Code 42 Engine Oil Temperature Sensor 7 Switched ECU power circuit problem g Code 43 TPS Auto Learn Initialization 35 Pin MA 1 7 Metal Cased ECU Pin circuit Function Below Min Limit 32 Pin ipa MSE 1 1 Plastic Cased ECU only 24 Pin MSE 1 0 Plastic Cased ECU Pin h Code 44 TPS Auto Learn Initializatio
21. 6 Start the engine and allow it to fully warm up and establish closed loop operation approximately 5 10 min Check the speed settings and adjust as necessary first the low idle speed and then the high speed setting Troubleshooting General When troubleshooting a problem on an engine with EFI basic engine operating problems must be eliminated first before faulting the EFI system components What appears to be an EFI problem could be something as simple as a fuel tank with debris in the bottom or a plugged vent Be sure the engine is in good mechanical operating condition and all other systems are functional before attempting to troubleshoot the EFI system Troubleshooting Guide Engine starts hard or fails to start when cold 1 Fuel pump not running Faulty spark plugs Old stale fuel Incorrect fuel pressure Speed sensor loose or faulty TPS offset incorrect initialization TPS faulty Engine temperature sensor faulty Faulty coils Low system voltage Faulty injectors oe A E i c m 5B 26 Engine starts hard or fails to start when hot 1 je PS A HA E Faulty spark plugs Fuel pump not running Fuel pressure low Insufficient fuel delivery TPS offset incorrect Initialization Speed sensor loose or faulty TPS faulty Engine temperature sensor faulty Faulty injectors Engine stalls or idles roughly cold or warm 1 Qs un eS T9 Faulty spark plugs Insufficient fuel delivery TPS of
22. 95 in Ib into new holes or 7 3 N m 65 in Ib into used holes See Figure 11 84 IZ N Figure 11 81 Adjusting Governor Lever 4 Inserta nail into the hole on the cross shaft and rotate the shaft counterclockwise as far as it will turn then torque the hex nut to 6 8 N m 60 in Ib See Figure 11 82 2 4 PF 1 a we tae OWT Figure 11 82 Holding and Tightening Governor Arm 5 Reconnect the lead wire to the fuel shut off solenoid if so equipped Install Throttle amp Choke Controls 1 Connect the choke linkage to the carburetor and choke actuator lever See Figure 11 83 Figure 11 84 Torquing Main Control Bracket 11 23 Section 11 Reassembly 3 Connect the governor spring from the main E cR control bracket to the appropriate hole in the j TW governor lever as indicated in the following charts Note that hole positions are counted from the pivot point of the governor lever See Figures 11 85 and 11 86 and the appropriate chart CN PH aa edid fiw amp Colored on End Only ji l BALIFIT zn reba ET Colored Completely Figure 11 86 Governor Spring I D Color Markings a Figure 11 85 Connecting Spring to Governor Lever 6 mm Governor Lever and Hole Position RPM Chart Gov Lever Governor Spring High Idle RPM Hole No Color Code 3801 4000 3601380 aA Clar Governor 345 360 3 Cla Leve
23. EC 17 90 0 669 DEEP 301 95 142 88 5 5625 B C 11 888 s NI r HS AKO M ia rif 7 16 14 UNC 28 INCH Ss ZT 21 00 0 827 1 DEEP X 1956 685 7 750 B C PILOT 177 80 7 000 Figure 1 4 Typical Engine Dimensions CH Series with Standard Flat Air Cleaner 1 6 Section 1 Safety and General Information Dimensions in millimeters Inch equivalents shown in 441 45 17 380 312 81 12 318 3 00 118 SPARK PLUG Ol FI Cr L ALTERNATE OIL FILL LOCATION FUEL RAIL INLET IGNITION COIL IGNITION COIL 4 87 184 SPARK PLUG e CRANKSHAFT h i j 7 ho y A M Re Pe aL P j j a ine If X S ANS CAU y AUTE n n V N LT if Hes 1S LLL jj PST we Wi 1447774 1 T v cese PS S77 L gt STARTER es ee l 15 70 142 04 62 16 618 5 582 3 626 ENGINE OIL FILTER REMOVAL 184 15 9X FRU MOUNTING HOLES sy p s FLYWHEEL SIDE Figure 1 5 Typical Engine Dimensions CH EFI Series with Heavy Duty Air Cleaner 1 7 Section 1 Safety and General Information General Specifications Power 3600 RPM exceeds Society of Automotive Engineers Small Engine Test Code J1940 RT disi 2 Oo o 13 4 kW 18 HP Plo 14 9 kW 20 HP I CH A E 16 4 kW 22 HP arbe Wr e X X 1
24. EFI Fuel System Components D E E A E E E E DIANA E E tan aarda a e o NEM A A E E E E ere mT eee Electrical Components Elechkonic Contor Un ECU Jesena E eE R E 5B 4 5B 5 ErieiDe SDESOO DOHE OP E as nee nemesis ones avec nipteceneeeensmeetatesneschesuscposeation meuieandeataussieanertaniesnscntaste 5B 6 Throttle Position Sensor TPS and Initialization Procedures eee 5B 7 5B 10 Etsi Tenpera ire OG OT oae HEISE PER RRNISEA E re tr USO mM mrerrrre Ty try rr nr tr 5B 10 5B 11 Br Bi qo NET cct 5B 11 5B 13 FECT ci T 5B 13 5B 14 TS COT asta se carats etna aise tease 5B 14 5B 17 TE UNE Ee a assoc noes cece R 5B 17 5B 18 Ae io M E 5B 18 TUE TRAINS m T X 5B 18 5B 19 yy EN a pees T 5B 19 Fuel Components IO T UT T 5B 19 5B 20 Puel Pressure KC SAGO ERR 5B 20 5B 22 2 Edu T 5B 22 E a ET EN EE EAE AEA E E EE 5B 22 PO E er 5B 22 5B 23 Throttle Body Intake Mamitold Assembly T ti 5B 23 iol pe ofetsre by acet siciuse anid d dai B ME tty err rer 5B 23 5B 24 miat Ere anle AS CE NT cm 5B 24 5B
25. Hold the governor lever away from the carburetor or hold the throttle lever so it is tight Float Replacement against the idle speed adjusting screw to negate If symptoms described in the carburetor the governor activation See Figure 5 14 Check troubleshooting guide indicate float level problems the speed with a tachometer and adjust it to 1500 remove the carburetor from the engine to check and RPM or replace the float Use a float kit to replace the float pin float valve clip and screw 3 Release the governor lever and allow the engine to return to the governed idle speed Check 1 Perform the removal procedures for the Heavy it with a tachometer against the equipment Duty Air Cleaner and Carburetor outlined in manufacturers recommended idle speed Section 9 Disassembly Governed Idle Speed RPM is typically 300 RPM approximate higher than the low idle speed If 2 Clean the exterior surfaces of dirt or foreign adjustment is necessary bend the adjusting tab material before disassembling the carburetor on the speed control assembly to set See Figure Remove the four mounting screws and carefully 5 13 separate the fuel bowl from the carburetor Do not damage the inner or bowl O Ring Transfer any remaining fuel into an approved container P Save all parts Fuel can also be drained prior to bowl removal by loosening removal of the bowl drain screw See Figure 5 15 Hold Throttle glever Against B
26. Ib Figure 11 12 Apply Camshaft Lubricant to Cam 6 mm Straight Shank Lobes 2 Position the timing mark of the crankshaft gear at the 12 o clock position 3 Turn the governor cross shaft clockwise until the lower end of the shaft contacts the cylinder Make sure the cross shaft remains in this position while installing the camshaft See Figure 11 13 Figure 11 10 Connecting Rod Bolts 4 Slide the camshaft into the bearing surface of the crankcase positioning the timing mark of the camshaft gear at the 6 o clock position Make sure that the camshaft gear and crankshaft gear mesh with both timing marks aligned See Figure 11 13 Figure 11 11 Torquing Connecting Rod End Cap Governor 6 Repeat the above procedure for the other Cross Shaft connecting rod and piston assembly Install Camshaft 1 Liberally apply camshaft lubricant see Section 2 to each of the cam lobes Lubricate the camshaft bearing surfaces of the crankcase and the Figure 11 13 Aligning Crankshaft and Camshaft camshaft with engine oil See Figure 11 12 Timing Marks Camshaft End Play Install the shim removed during disassembly onto the camshaft 2 Position the camshaft end play checking tool on the camshaft See Figure 11 14 Figure 11 14 Checking Camshaft End Play 3 Apply pressure on the camshaft end play checking tool pushing camshaft toward crankshaft Use a feeler gauge to measure the camshaft end play between the shi
27. NOTE The clamp brackets and stop collar mounted on the throttle shaft should still be in their original positions See Figure 5A 2 and not require any readjustment resetting Continue with steps 6 and 7 If the mounted position of any one of these was affected or changed it will be necessary to check and reset the position of each before proceeding Follow the complete instructions listed after step 7 then continue with steps 6 and 7 6 Manually move the governor lever toward the carburetor as far as it will go 7 Check that the throttle plate is now fully open or reposition the carburetor slightly on the mounting screws so it is fully open Torque the mounting screws to 9 9 N m 88 in Ib Instructions for Checking Positioning the Clamp Brackets Mounted on the Throttle Shaft Use only if the position or mounting of the clamp bracket s has been disturbed Figures show the carburetor removed from the engine for clarity 5A 6 Idle Speed Clamp Bracket Position 1 Counting the number of turns back the idle speed adjustment screw off counterclockwise so only 1 to 1 1 2 of the threads are visible See Figure 5A 8 Idle Speed Clamp Bracket Mounting Screw Figure 5A 8 Backing Off Idle Speed Screw 2 Loosen the clamp bracket mounting screw and pivot the throttle shaft to fully close the throttle plate See Figure 5A 9 Figure 5A 9 Closing Throttle Plate 3 Hold the throttle plate closed and rota
28. Note 6 Remove the breather filter from chamber See which side of the engine has the oil fill and or fuel Figure 9 45 pump valve cover See Figure 9 45 Figure 9 43 Removing Breather Filter Figure 9 45 Removing Valve Covers 9 11 Section 9 Disassembly Remove Ignition Modules 3 Leave the wiring harness attached to the 1 Disconnect the lead s from each ignition manifold module See Figure 9 46 Modules for non SMART SPARK ignition systems have only one Aluminum kill lead Intake Manifold Figure 9 46 Disconnecting Leads from Ignition Modules 2 Rotate the flywheel so the magnet is away from the modules 3 Remove the mounting screws and ignition modules Note the position of ignition modules Two Barrel 2 Intake Manifold Figure 9 47 Position of SMART SPARK Ignition Module Figure 9 48 Removing Intake Manifold Remove Intake Manifold 1 Remove the four hex flange screws securing the intake manifold to the cylinder heads Note which screws hold the wiring clamps 2 Remove the intake manifold and the intake manifold gaskets aluminum intake manifolds or O Rings plastic intake manifolds See Figure 9 48 9 12 EF Figure 9 49 Bolt Wiring Harness Detail Remove Spark Plugs 1 Remove the spark plug from each cylinder head Figure 9 50 Removing Spark Plugs Remove Cylinder Heads and Hydraulic Lifters NOTE Cylinder heads are retained using either hex flange s
29. Outlet Line to Carburetor Mechanical Fuel Pump Inlet Line Figure 5 2 Mechanical Fuel Pump 5 3 Section 5 Fuel System and Governor Carburetor General Engines in this series are equipped with Keihin fixed main jet carburetors CH18 740 engines use a one barrel carburetor Most applications use a fuel shut off solenoid installed in place of the fuel bowl retaining screw and also contain an accelerator pump All carburetors feature a self relieving choke like or similar to the one shown in the exploded view A WARNING Explosive Fuel Gasoline is extremely flammable and its vapors can explode if ignited Store gasoline only in approved containers in well ventilated unoccupied buildings away from sparks or flames Do not fill the fuel tank while the engine is hot or running since spilled fuel could ignite if it comes in contact with hot parts or sparks from ignition Do not start the engine near spilled fuel Never use gasoline as a cleaning agent on page 5 10 CH750 engines use a Keihin BK two barrel carburetor on a matching intake manifold This carburetor with related servicing and adjustments is covered beginning on page 5 11 Troubleshooting Carburetor Related Causes Possible Cause Probable Remedy 1 Engine starts hard runs roughly 1 or stalls at idle speed 2 Engine runs rich indicated by black sooty exhaust smoke misfiring loss of speed and power governor hunting or excessive t
30. damage NOTE Synthetic oils meeting the listed classifications may be used with oil changes performed at the recommended intervals However to allow piston rings to properly seat anew or rebuilt engine should be operated for at least 50 hours using standard petroleum based oil before switching to synthetic oil A logo or symbol on oil containers identifies the API service class and SAE viscosity grade See Figure 6 1 A Figure 6 1 Oil Container Logo The top position of the symbol shows service class such as API SERVICE CLASS SJ The symbol may show additional categories such as SH SG CC or CD The center portion shows the viscosity grade such as SAE 10W 30 If the bottom portion shows Energy Conserving it means that oil is intended to improve fuel economy in passenger car engines 6 1 Section 6 Lubrication System Checking Oil Level The importance of checking and maintaining the proper oil level in the crankcase cannot be overemphasized Check oil BEFORE EACH USE as follows 1 Make sure the engine is stopped level and is cool so the oil has had time to drain into the sump 2 Clean the area around the dipstick before removing it This will help to keep dirt grass clippings etc out of the engine 3 Remove the dipstick wipe oil off Reinsert the dipstick into the tube until fully seated See Figure 6 2 Cil Fill Cap Valve Cover Location Figure 6 2 Location of Oil Fill Cap and Dipsti
31. fuel pressure fuel pump c Combustion air air cleaner dirty restricted intake leak throttle bores d Base engine problem rings valves e Exhaust system leak muffler flange oxygen sensor mounting boss etc f Fuelin the crankcase oil Altitude Blocked or restricted fuel return circuit to tank 98 Code 42 Source Engine Oil Temperature Sensor Explanation Not sending proper signal to ECU Expected Engine Response Engine may be hard to start because ECU can t determine correct fuel mixture Possible Causes 1 Temperature Sensor Related a Sensor wiring or connection 2 Engine Wiring Harness Related 35 Pin MA 1 7 Metal Cased ECU a Pin circuits 14 and or 27A damaged wires connectors or routed near noisy signal coils alternator etc b ECU to harness connection problem 2 Engine Wiring Harness Related 24 Pin MSE 1 0 Plastic Cased ECU a Pin circuits 4 6 and or 4A damaged wires connectors or routed near noisy signal coils alternator etc b ECU to harness connection problem Section 5B EFI Fuel System 2 Engine Wiring Harness Related 32 Pin MSE 1 1 Plastic Cased ECU a Pin circuits 4 6 and or 4A damaged wires connectors or routed near noisy signal coils alternator etc b ECU to harness connection problem 3 System Related a Engine is operating above the 176 C 350 F temperature sensor limit Code 43 and 44 32 Pin
32. no continuity resistance from each stator lead to ground the stator is OK not shorted to ground using an ohmmeter If resistance or continuity is measured the stator leads are shorted to ground Replace stator Perform same test as step 1 above Ifthe voltage is 14 7 volts or less the charging system is OK The battery is unable to hold a charge Service battery or replace as necessary Battery Continuously Charges at If voltage is more than 14 7 volts the rectifier High Rate regulator is faulty Replace rectifier regulator 8 27 Section 8 Electrical System and Components Troubleshooting Guide 3 Amp Battery Charging System with 70 Watt Lighting Stator NOTE Zero ohmmeters on each scale to ensure accurate readings Voltage tests should be made with engine running at 3000 RPM no load Battery must be good and fully charged 1 With engine running at 3000 RPM measure 1 If voltage is more than 12 5 volts charging voltage across battery terminals using a DC system is OK voltmeter If voltage is 12 5 volts or less the stator or diode are probably faulty Test the stator and diode Tests 2 3 and 4 2 Disconnect the charging lead from battery 2 If voltage is 28 volts or more stator winding is OK With engine running at 3000 RPM measure voltage from charging lead to ground using a If voltage is less than 28 volts test stator using DC voltmeter an ohmmeter Tests 3 and 4 3 With char
33. nor is any internal servicing permitted or possible If a 4 Choke plate in carburetor not opening problem is encountered and determined to be caused completely by the load block the carburetor should be replaced 5A 3 Section 5A LPG Fuel Systems High Altitude Operation The standard carburetor calibrations will provide proper operation up to altitudes of 1500 m 5000 ft No internal changes are necessary or available for either carburetor NOTE Carburetor adjustments should be made only after the engine has warmed up Idle Speed Adjustment 1 Start the engine and run at half throttle for 5 to 10 minutes Check that the throttle and choke Nikki carburetor plates can open fully 2 Place the throttle control into the idle or slow position Turn the low idle speed adjusting screw See Figure 5A 2 or 5A 3 in or out to obtain a low idle speed of 1200 RPM 75 RPM or set to application specifications Check the speed using a tachometer NOTE The actual low idle speed RPM depends on the application Refer to the equipment manufacturer s recommendations The low idle speed for basic engines is 1200 RPM LPG Fuel System Component Service LPG Carburetor Cleaning The carburetor may be cleaned if necessary Removal from the engine and limited disassembly will aid in cleaning NOTE Impco Carburetor Do not loosen or alter the mounted position of the clamping brackets and or stop collar on the throttle shaft
34. not shown in drawing is vented to secondary chamber so that rupture of this diaphragm would direct fuel into the carburetor Fuel now moves through passage E past secondary valve 25 into secondary area C As negative pressure vacuum is created at the carburetor venturi and is transmitted through the dry gas hose to chamber C secondary diaphragm 12 is drawn down and contacts the secondary lever 16 Fuel will flow in proportion to air velocity through the carburetor venturi ensuring an ideal mixture at all engine speeds Whenever the engine is operating the vacuum diaphragm 10 is down against the floor H and the spring 11 is compressed The idle and starting adjustment is made with a tamper resistant screw 17 which regulates the whisker wire system not shown opening up the secondary orifice slightly but only when the vacuum diaphragm is drawn down Very little vacuum is needed to start this vacuum diaphragm travel 0 2 in Mercury to start and 0 5 in Mercury for full travel The instant the engine stops rotating loss of vacuum in section D releases diaphragm 10 causing bumper K to push against secondary lever 16 overcoming action of whisker wire and ensuring 100 lock off This patented Beam design will lock off primary pressures up to five times in excess of normal and permits starting without priming or choking 5A 10 Odvco0 oocgrxom Sor nm T N 1 E
35. of the main harness Both tests should indicate continuity 24 Pin MSE 1 0 Plastic Cased ECU Check for continuity from pin 15 of the ECU connector see page 5B 31 to the shell of the oxygen sensor and from pin 11 to the sensor connector terminal of the main harness Both tests should indicate continuity 32 Pin MSE 1 1 Plastic Cased ECU Check for continuity from pin 719 of the ECU connector see page 5B 32 to the shell of the oxygen sensor and from pin 20 to the sensor terminal of the main harness Both tests should indicate continuity a If there is no continuity displayed in either of the tests check the harness circuit for breaks or damage and the connections for poor contact moisture or corrosion If no continuity was found in the first test also check for a poor broken ground path back through the exhaust system engine and mounting sensor is grounded through its shell b If continuity is indicated go to step 6 With the key switch in the on run position using a high impedance voltmeter check the voltage from the wiring harness oxygen sensor connector to the engine ground location Look for a steady voltage from 350 550 mv 0 35 0 55 v a If voltage reading is not as specified move the black voltmeter lead to the negative post of the battery to be certain of a good ground If the voltage is still not correct the ECU is probably bad b If voltage readings are correct clear the fau
36. to the lower blower housing hole See Figure 11 64 Figure 11 64 Ground Lead Details 5 Tighten all of the shrouding fasteners Torque the blower housing screws to 6 2 N m 55 in Ib ina new hole or to 4 0 N m 35 in Ib in a used hole Torque the shorter M5 side baffle screws to 4 0 N m 35 in Ib See Figure 11 65 Torque the upper M5 side baffle screws into cylinder head to 6 2 N m 55 in Ib in a new hole or to 4 0 Ne m 35 in Ib in a used hole Torque the two rear M6 baffle mounting screws to 10 7 N m 95 in Ib in a new hole or to 7 3 N m 65 in Ib in a used hole See Figure 11 66 11 18 Section 11 Reassembly 7 Torque the four breather cover screws to 7 3 N m 65 in Ib in the sequence shown in Figure 11 68 Figure 11 65 Tighten Short Screws to Torque Specified Figure 11 68 Breather Cover Fastener Torque Sequence Reconnect Rectifier Regulator 1 Install the rectifier regulator in the blower housing if removed previously then connect the rectifier regulator ground lead with the washer and silver screw through the eyelet as shown in Figure 11 69 If a grounding bracket is used secure with the lower mounting screw and washer against the outer side of the rectifier regulator See Figure 11 71 Figure 11 66 Tighten Baffle Mounting Screws 6 If an overlapping style flywheel screen is used attach it to the supports or flywheel For a metal flywheel screen apply Loctite No
37. 1414 mm 1 1033 mm 0 043 in Nominal RED 1 2938 1 3700 mm 1 3319 mm 0 052 in Nominal Remove the closure plate If end play requires adjustment remove the original spacer and install the appropriate size shim spacer in its place Then follow the procedure under Install Closure Plate Assembly JJ Install Closure Plate Oil Seal 1 Check to make sure that there are no nicks or burrs in the crankshaft bore of the closure plate 2 Applya light coat of engine oil to the outside diameter of the oil seal 3 Drive the oil seal into the closure plate using a seal driver Make sure the oil seal is installed straight and true in the bore to the depth shown in Figure 11 18 Oil Seal Figure 11 18 Oil Seal Depth in Closure Plate Install Closure Plate Assembly RTV sealant is used as a gasket between the closure plate and the crankcase Refer to Section 2 for a listing of approved sealants Always use fresh sealant Using outdated sealant can result in leakage 1 Be sure the sealing surfaces have been cleaned and prepared as described at the beginning of Section 10 or in Service Bulletin 252 2 Check to make sure that there are no nicks or burrs on the sealing surfaces of the closure plate or crankcase Section 11 Reassembly 3 Apply a 1 5 mm 1 16 in bead of sealant to the 6 Install the ten hex flange screws securing the sealing surface of the closure plate See Figure closure plate to the crankcase Torque
38. 17 8 C 0 F SAE 10 2 Remove cross shaft Adjustment Slight readjustment may be needed after a few hours on a new clutch to accommodate normal run in wear Firm pressure should be required to engage clutch 40 45 pounds pull at lever handle Readjust if clutch slips and overheats or if clutch handle jumps out after 5 engagement Use the following procedure 3 Remove housing bolts 4 and slide housing off 4 Loosen bolts securing clutch assembly to crankshaft then remove locking screw Pull clutch assembly off 6 To replace clutch simply turn adjusting collar off 1 Release clutch and remove nameplate Using a and remove plate large screwdriver turn adjusting ring clockwise one notch at a time until firm pressure is required to engage clutch See Figure 12 2 Adjusting ring is spring loaded and does not have to be loosened before adjustment is made Do not attempt to pry or force spring lock away from the ring Reverse procedure for reassembly Adjust and lubricate following previous instructions Spring Lock Figure 12 2 Adjusting Clutch 12 2 KOHLER ENGINES FOR SALES AND SERVICE INFORMATION IN U S AND CANADA CALL 1 800 544 2444 KohlerEngines com ENGINE DIVISION KOHLER CO KOHLER WISCONSIN 53044 2011 by Kohler Co All rights reserved FORM NO 24 690 06 Rev A ISSUED 9 10 REVISED 1 11 1P24 690 06 50531 99104 1
39. 20 in Ib 11 21 Section 11 Reassembly Figure 11 77 Ground Lead on Carburetor Mounting Screw One Barrel Carburetor 3 Torque the two carburetor mounting screws to 6 2 7 3 N m 55 65 in Ib Two Barrel Carburetor Models 1 Usea new carburetor gasket Make sure all holes align and are open 2 Apply Loctite 242 to the shorter inner set of threads of any removed studs 3 Assemble carburetor gasket and carburetor to the intake manifold and start any removed studs Use two hex nuts locked flange to flange and tighten each of the studs until bottomed tight See Figure 11 78 11 22 A pa Si i Figure 11 78 Installing Studs and Carburetor Two Barrel Carburetor 4 Connect the ground lead and fuel solenoid lead as equipped See Figure 11 79 Figure 11 79 Connecting Ground Lead Two Barrel Carburetor Install External Governor Controls 1 Install the governor lever onto the governor cross shaft See Figure 11 80 Section 11 Reassembly 2 Make sure the throttle linkage is connected to the governor lever and the throttle lever on the carburetor 3 Move the governor lever toward the carburetor as far as it will go wide open throttle and hold in position See Figure 11 81 Figure 11 83 Connecting Choke Linkage 2 Mount the main control bracket and air cleaner support bracket if used to the cylinder heads using the four hex flange screws Torque the screws to 10 7 N m
40. 5 0 psi the tester should indicate a change to no continuity switch open The switch should 2 Install the switch into the tapped hole in the remain open as the pressure is increased to 90 psi breather cover See Figure 6 8 maximum 3 Torque the switch to 4 5 N m 40 in Ib 3 Gradually decrease the pressure through the range of 3 0 5 0 psi The tester should indicate a Testing change to continuity switch closed down to Compressed air a pressure regulator pressure gauge 0 psi and a continuity tester are required to test the switch 4 Replace the switch if it does not operate as 1 Connect the continuity tester across the blade specified terminal and the metal case of the switch With 0 psi pressure applied to the switch the tester should indicate continuity switch closed 6 5 Section 6 Lubrication System 6 6 Section 7 Retractable Starter PN WARNING Spring Under Tension Retractable starters contain a powerful recoil spring that is under tension Always wear safety goggles when servicing retractable starters and carefully follow instructions in this section for relieving spring tension To Remove Starter 1 Remove the five hex flange screws securing the starter to the blower housing 2 Remove the starter To Install Starter 1 Install the retractable starter onto the blower housing leaving the five hex flange screws slightly loose 2 Pull the starter handle out until the pawls engage in the dr
41. 61 Start a few of the screws to hold it in place On two barrel carburetor models lift the debris shield up above the mounting surface as the blower housing is installed Make sure Figure 11 58 Installing Screws Locations 3 and the ground lead fuel solenoid lead and oil 4 pressure switch leads are accessible and in proper position See Figures 11 61 and 11 62 7 Install the inner baffles using the two remaining hex flange screws see Figures 11 59 and 11 60 and finger tighten Do not torque the screws at this time they will be tightened after the blower housing and outer baffles are installed Figure 11 62 Routing Wiring Harness and Leads Two Barrel Models Figure 11 60 Finger Tighten Two Remaining Cover Screws 11 17 Section 11 Reassembly 3 Position the outer baffles and loosely start the mounting screws The two M6 screws go into the back of the cylinders The short M5 screws go into the lower holes closest to the blower housing The short screw on the oil filter side is also used to mount the wire harness clip Be sure any wire harnesses or leads are routed out through the proper offsets or notches so they will not be pinched between the blower housing and baffles See Figure 11 63 Figure 11 63 Routing Wiring Harness and Leads 4 If the rectifier regulator was not removed attach the ground wire or metal grounding bracket for the rectifier regulator using the silver colored screw and washer
42. Carburetor only Accelerator Pump Cover Diaphragm Diaphragm Spring O Ring Rubber Boot Bushing Return Spring oO ae ae Des See Note on Page A 1 D do 16 O a9 Accelerator Pump Version Only Figure 5 10 CH18 740 Carburetor Exploded View Components such as the throttle and choke shaft assemblies throttle plate choke plate low idle fuel needle and others are available separately Always refer to the Parts Manual for the engine being serviced to ensure the correct repair kits and replacement parts are ordered Service repair kits available for the carburetor and affiliated components are Carburetor Repair Kit Float Kit High Altitude Kit 1219 2434 m 4 000 8 000 ft Solenoid Assembly Kit Accelerator Pump Seal and Bushing Kit Accelerator Pump Diaphragm Kit Choke Repair Kit 5 10 NOTE If accelerator pump rod movement is restricted or corrosion exists in the pump rod housing hole use a 0 153 in 3 9 mm or No 23 drill and carefully clean resize the hole to restore proper operation Blow out the hole with air and lightly lubricate with oil on reassembly Carburetor Keihin BK Two Barrel Carburetor CH750 The carburetor used on CH750 engines is a Keihin two barrel side draft design with fixed main jets See Figure 5 11 A self relieving choke similar to that used on single venturi carburetors is also contained in the design The circuits within the carburetor function as descri
43. Do not use reinstall any loosened or removed studs 3 Install the cylinder head and start the four new hex flange screws 2 Install new mounting stud s into the crankcase NOTE When installing cylinder heads new hex a Thread and lock two of the mounting nuts flange screws should always be used together on the smaller diameter threads 4 Torque the hex flange screws in two stages first b Thread the opposite end of the stud with the to 22 6 N m 200 in Ib finally to 41 8 N m preapplied locking compound into the 370 in Ib following the sequence in Figure crankcase until the specified height from the 11 42 crankcase surface is achieved See Figure 11 43 When threading in the studs use a steady tightening motion without interruption until the proper height is obtained Otherwise the frictional heat from the engaging threads may cause the locking compound to set up prematurely The studs closest to the lifters must have an exposed height of 75 mm 2 15 16 in The studs furthest from the lifters must have an exposed height of 69 mm 2 3 4 in c Remove the nuts and repeat the procedure as required Figure 11 41 Torquing Cylinder Head Fasteners 11 12 Figure 11 43 Installing New Mounting Studs to Specified Height 3 Check that the dowel pins are in place and install a new cylinder head gasket printing up 4 Install the cylinder head Match the numbers on the cylinder heads and the cr
44. EFI to ground or shorted to battery system The chart will enable you to review the entire Explanation Fuel pump ignition coils and fuel system in about 10 15 minutes Using the chart the injectors will not function because the accompanying diagnostic aids listed after the chart fuel pump relay circuit is either open and any signaled fault codes you should be able to shorted to ground or may be on quickly locate any problems within the system continuously if shorted to battery Expected Engine Response Engine will not run or fuel pump will continue to run when switch is off Possible Causes 1 Fuel Pump Relay Related a Bad fuel pump relay Primary side open or shorted 2 Fuel Pump Related a Fuel pump open or shorted internally 3 Engine Wiring Harness Related a Fuel pump fuse F1 open b Broken or shorted wire in harness ECU pin 28 to fuel pump relay pin 86 Ignition switch to fuel pump relay pin 85 4 ECU Related a Circuit controlling fuel pump relay damaged Code 61 Source Explanation Denotes the end of fault codes If signaled first no other fault codes are present 5B 43 Section 5B EFI Fuel System Bosch EFI Diagnostic Flow Diagram Proceed to Start of Test for retest KEY ON MALFUNCTION INDICATOR LIGHTS ON No REFER TO DIAGNOSTIC AID 1 FAULT CODES ARE FAULT CODES PRESENT REFER TO DIAGNOSTIC AID 2 FAULT CODES CLEAR CODES DOES ENGINE
45. Figures 9 16 and 9 17 9 5 Section 9 Disassembly Figure 9 20 Mechanical Fuel Pump Figure 9 22 Rear Air Cleaner Bracket Some Models Remove Control Panel If So Equipped 1 Disconnect the Oil Sentry Indicator Light 2 Mark the spring hole locations and disconnect wires the spring from the governor lever See Figure 9 23 2 Disconnect the choke control cable from the control bracket 3 Disconnect the throttle control cable or shaft 4 Remove the panel from the blower housing Remove Throttle amp Choke Controls Remove the four hex flange screws securing the control bracket and rear air cleaner bracket some models to the cylinder heads See Figures 9 2 and 9 22 er E e w V AL Figure 9 23 Disconnecting Spring from Bracket 3 Remove the choke linkage from the choke actuator lever and carburetor See Figure 9 24 Actuator Lever 9 6 Section 9 Disassembly Remove External Governor Controls 2 One Barrel Carburetor Models Only Remove 1 Loosen the hex flange nut and remove the the two carburetor mounting screws See Figure governor lever from the cross shaft See Figure 9 27 9 25 Leave lever attached to the throttle linkage and lay assembly on the top of the crankcase Two Barrel Carburetor Models Only If required use two hex flange nuts locked together and remove the two carburetor mounting studs on the starter side of the intake manifold and one of the studs on the oil filter
46. GENERAL NOTE NO 9 SAFETY SWITCH J1 25 N O GROUND J1 10 J1 9 SENSOR ENCINE SPEED 5 21 PD bia Pe Rea MX ea uc mv E ge Cylinder 1 y 8 Shela Grove 5 eue Qo m 2 To s tO e MEN wie cing Nowe A Al Si gt CIA E IJ 5 Sj 4 0 opp SS eS s a opal 712 o 123 8 o 0 124 Hs 2l us tojo o 26 J1 12 nS SE A AS A AAA ACA 12 0 128 dis clu e A S rk cA Alo off fo T MALFUNCTION Talo ob 1 1 a e a E lt a Bla T 1 cm i 35 d i 18 m E a d2 T T Y N 5 VT a a 20 O1 2 1 FA O z EN T 5 z T E d H 6 10A a Motor Throttle INJECTOR 1 INJECTOR 2 Temperature Position o Sensor Sensor 2 1 12 a E I GROUNDING NOTES A Battery B Lambda Sensor C Fuel Pump D Shield 2 1 12 25 SEE Attached to engine block near starter GROUNDING The sensor return is via the engine muffler NOTE B If a slip joint is used a grounding strap is required If a 2 leaded sensor is used pin 4 or pin 21 can be used for the is the return Attached to the chassis Attached to the engine block close to the coils CONNECTOR DIAGNOSTIC SEE GROUND NOTE C 50 D D 87 RELAY MAIN POWER co 11 12 SWITCH IGNI TION N O BATTERY GROUND Ll SEE GROUNDING NOTE A A d BATTERY GENERAL SYSTEM INSTALLATION NOTES The ignition switch must maintain a constant voltage to c
47. If the return line is good replace the regulator see Regulator Service on page 5B 21 b If the pressure is too low install in line T between the pump and regulator and retest the pressure at that point If it is too low there also replace the fuel pump 3 If the pump did not activate step 2 disconnect the plug from the fuel pump Connect a DC voltmeter across the terminals in the plug turn on the key switch and observe if a minimum of 7 volts is present If voltage is between 7 and 14 turn key switch off and connect an ohmmeter between the terminals on the pump to check for continuity a If there was no continuity between the pump terminals replace the fuel pump b If the voltage was below 7 test the wiring harness and relay as covered in the Electrical Relay section 4 If voltage at the plug was good and there was continuity across the pump terminals reconnect the plug to the pump making sure you have a good connection Turn on the key switch and listen for the pump to activate a If the pump starts repeat steps 1 and 2 to verify correct pressure b If the pump still does not operate replace it 5B 20 Fuel Pressure Regulator Figure 5B 27 External Fuel Pressure Regulators with Base Figure 5B 28 Internal Fuel Pressure Regulator General The fuel pressure regulator assembly maintains the required operating system pressure of 39 psi 3 A rubber fiber diaphragm see Figure 5B 2
48. Plastic Cased ECU Locate pins 30 and 31 in the 32 pin connector See page 5B 32 2 Disconnect connector from relay and locate terminal 87 in connector 3 Using an ohmmeter set on the Rx1 scale check the resistance in circuits as follows 35 Pin MA 1 7 Metal Cased ECU Check between terminal 87 and pin 1 for coil 1 Repeat the test between terminal 87 and pin 19 for coil 2 24 Pin MSE 1 0 Plastic Cased ECU Check between terminal 87 and pin 22 for coil 1 Repeat the test between terminal 87 and pin 23 for coil 2 32 Pin MSE 1 1 Plastic Cased ECU Check between terminal 87 and pin 30 for coil 1 Repeat the test between terminal 87 and pin 31 for coil 2 A reading of 1 8 4 0 Q in each test indicates that the wiring and coil primary circuits are OK a If reading s are not within specified range check and clean connections and retest b If reading s are still not within the specified range test the coils separately from main harness as follows 1 Disconnect the red and black primary leads from the coil terminals 2 Connect an ohmmeter set on the Rx1 scale to the primary terminals Primary resistance should be 1 8 2 5 Q 5B 18 3 Disconnect the secondary lead from the spark plug Connect an ohmmeter set on the Rx10K scale between the spark plug boot terminal and the red primary terminal Secondary resistance should be 13 000 17 500 Q 4 If the secondary resis
49. RC RR Note 1 Idle Switch not used Diagnostic of TPS Signal Implausible is disabled in code O Sensor Short to Battery diagnostic detection is disabled with SAS fuel cutoff calibrated out Air Temperature Sensor not used Temperature Sensor Signal Implausible diagnostic detection is calibrated out with TPLAUS set to 50 C System too Lean used to be O Sensor Short to Ground P0131 System too Rich used to be O Sensor Control at Lower Limit P0019 Obtainable only with ECU 24 584 28 5 or later Will not blink out ve pe SY J uo Tu 5B 37 Section 5B EFI Fuel System Code 21 Source Engine Speed Sensor Explanation ECU receiving inconsistent tooth count signals from speed sensor Expected Engine Response Possible misfire as ECU attempts to resynchronize during which time fuel and spark calculations are not made Possible Causes 1 Engine Speed Sensor Related a b e Sensor connector or wiring Sensor loose or incorrect air gap Flywheel key sheared 2 Speed Sensor Ring Gear Related a Damaged teeth b Varying gap gear loose out of alignment 3 Engine Wiring Harness Related 35 Pin MA 1 7 Metal Cased ECU a b Pin circuits 3 and or 21 wiring or connectors Shielding for pin circuits 3 and or 21 damaged or not properly grounded Poor or improper grounds in system battery ECU oxygen sensor shielding fuel pump ignition output Pin circuit
50. START Yes No REFER TO DIAGNOSTIC AID 3 RUN ON Yes L OPERATE AT VARIOUS SPEED LOAD CONDITIONS ARE FAULT REFER TO DIAGNOSTIC AID 2 CODES PRESENT FAULT CODES END T TEST CRANK ENGINE DOES MIL GO OFF Yes KEY OFF AND KEY ON LISTEN FOR FUEL PUMP REFER TO DIAGNOSTIC AID 4 SPEED SENSOR DOES FUEL PUMP CYCLE ON THEN OFF AFTER 1 2 SECONDS LOCATE ELECTRICAL RELAY WHILE HOLDING RELAY KEY OFF AND KEY ON DOES RELAY CYCLE ON THEN OFF AFTER 1 2 SECONDS Proceed to Start of Test for retest Yes Yes REFER TO DIAGNOSITC AID 5 FUEL PUMP REFER TO DIAGNOSTIC AID 6 RELAY WHILE CRANKING CHECK IGNITION SYSTEM REFER TO DIAGNOSTIC AID 7 IGNITION SYSTEM Yes WHILE CHECKING CHECK INJECTOR FUEL DELIVERY WET SPARK PLUG Yes INSTALL IN LINE PRESSURE GAUGE AND KEY ON FUEL PRESSURE IN SPECIFICATION No REFER TO DIAGNOSTIC AID 8 FUEL SYSTEM ELECTRICAL No REFER TO DIAGNOSTIC AID 9 FUEL SYSTEM REFER TO DIAGNOSTIC AID 10 Yes BASE ENGINE Operate for an appropriate period of time based upon original fault codes Figure 5B 44 5B 44 Section 5B EFI Fuel System Flow Chart Diagnostic Aids 11 Code 51 Injector 1 32 Pin MSE 1 1 Plastic Diagnostic Aid 1 SYSTEM POWER MIL does not Cased ECU only illuminate when key is turned on 12 Code 52 Injector 2
51. Switch r BS i 0 28 0 33 mm Section 8 Electrical System and Components Ignition Modules _ Spark Plug Figure 8 4 Capacitive Discharge Fixed Timing Ignition System The timing of the spark is controlled by the location of the flywheel magnet group as referenced to engine top dead center Spark Plug i Figure 8 5 Capacitive Discharge Ignition Module Schematic Operation As the flywheel rotates the magnet erouping passes the input coil L1 The corresponding magnetic field induces energy into the input coil L1 The resultant pulse is rectified by D1 and charges capacitor C1 As the magnet assembly completes its pass it activates the triggering device L2 which causes the semiconductor switch SCS to turn on With the device switch ON the charging capacitor C1 is directly connected across the primary P of the output transformer T1 As the capacitor discharges the current initiates a fast rising flux field in the transformer core A high voltage pulse is generated from this action into the secondary winding of the transformer This pulse is delivered to the spark plug gap Ionization of the gap occurs resulting in an arc at the plug electrodes This spark ignites the fuel air mixture in the combustion chamber Troubleshooting CD Ignition Systems The CD ignition systems are designed to be trouble free for the life of the engine Other than periodically checking replacing the
52. approved Any failures resulting from use of these fuels will not be warranted Gasoline Ether blends Methyl Tertiary Butyl Ether MTBE and unleaded gasoline blends up to a maximum of 1576 MTBE by volume are approved as a fuel for Kohler engines Other gasoline ether blends are not approved Section 1 Safety and General Information Periodic Maintenance Instructions A WARNING Accidental Starts Disabling engine Accidental starting can cause severe injury or death Before working on the engine or equipment disable the engine as follows 1 Disconnect the spark plug lead s 2 Disconnect negative battery cable from battery Maintenance Schedule Normal maintenance replacement or repair of emission control devices and systems may be performed by any repair establishment or individual however warranty repairs must be performed by a Kohler authorized service center Fill fuel tank Section 5 Daily or Before Check oil level Section 6 Starting Engine Check air cleaner for dirty loose or damaged parts Section 4 Check air intake and cooling areas clean as necessary Section 4 Replace air cleaner element Section 4 Change oil More frequently under severe conditions Section 6 Remove cooling shrouds and clean cooling areas Section 4 Check oil cooler fins clean as necessary if equipped Section 6 Every 100 Hours Check spark plug condition and gap Section 8 Every 200 Hours Change oil filter Section 6 Cha
53. bore and perpendicular to the piston pin 10 4 3 Piston to bore clearance is the difference between the bore diameter and the piston diameter step 2 minus step 1 Flywheel Inspection Inspect the flywheel for cracks and the flywheel keyway for damage Replace the flywheel if it is cracked Replace the flywheel the crankshaft and the key if flywheel key is sheared or the keyway is damaged Inspect the ring gear for cracks or damage Kohler does not provide the ring gear as a serviceable part Replace the flywheel if the ring gear is damaged Cylinder Head and Valves Inspection and Service After cleaning check the flatness of the cylinder head and the corresponding top surface of the crankcase using a surface plate or piece of glass and feeler gauge as shown in Figure 10 5 The maximum allowable out of flatness is 0 076 mm 0 003 in Figure 10 5 Checking Cylinder Head Flatness Carefully inspect the valve mechanism parts Inspect the valve springs and related hardware for excessive wear or distortion Check the valves and valve seat area or inserts for evidence of deep pitting cracks or distortion Check clearance of the valve stems in the euides See Figure 10 6 for valve details and specifications EXHAUST VALVE E F HZ G Seat Angle Guide Depth 4 mm 0 1575 in Valve Face Angle 45 Valve Margin Min 1 5 mm 0 0591 in A B C D E z G H Figure 10 6 Valve Details Hard
54. cleaner base gasket Reconnect the throttle and choke linkages and the fuel and vacuum lines Reinstall the air cleaner base and breather tube Secure base with two mounting nuts Torque nuts to 9 9 N m 88 in Ib Install the rest of the air cleaner system 6 Check to be sure all system connections are tight 7 Resetidle RPM and recheck high idle governed speed after starting and allowing sufficient warm up time Electric Lock Off Filter Assembly Functional Test The electric lock off can be easily tested to verify that it is functional Remove it from the system for testing Using a 12 volt power supply or battery connect one wire lead to the positive lead of power supply and touch remaining wire lead to negative lead of power supply When connection is made an audible click should be heard indicating the opening of the lock off While energized blow compressed air through it to determine if it is blocked or restricted Figure 5A 15 Figure 5A 16 Electric Lock Off Filter Assembly Filter Service The filter inside the lock off assembly should be replaced every 500 hours of operation or if it becomes blocked or restricted Cleaning of the filter element is not recommended Order a replacement filter element by the appropriate Kohler part number Section 5A LPG Fuel Systems Vaporizer Assembly The outer surface of the vaporizer should be kept free of dirt and debris accumulation which will ca
55. conditions Bad Condition The valve depicted here should be Coking Coking is normal on intake valves and is not replaced Note the warped head margin damaged harmful If the seat is good the valve could be reused and too narrow These conditions could be attributed after cleaning to excessive hours or a combination of poor operating conditions 10 6 Excessive Combustion Temperatures The white deposits seen here indicate very high combustion temperatures usually due to a lean fuel mixture Section 10 Inspection and Reconditioning Stem Corrosion Moisture in fuel or from condensation are the most common causes of valve stem corrosion Condensation occurs from improper preservation during storage and when engine is repeatedly stopped before it has a chance to reach normal operating temperatures Replace corroded valves Gum Gum deposits usually result from using stale gasoline Gum is a prevalent cause of valve sticking The cure is to ream the valve guides and clean or replace the valves depending on their condition Overheating An exhaust valve subject to overheating will have a dark discoloration in the area above the valve guide Worn guides and faulty valve springs may cause this condition Also check for clogged air intake and blocked fins when this condition is noted 10 7 Section 10 Inspection and Reconditioning Valve Guides If a valve guide is worn beyond specifications it will not gui
56. cranking voltage of 7V The throttle position sensor TPS connection shown is for CCW rotation of the TPS from idle to wide open throttle as viewed from the throttle shaft side of the TPS CW rotation requires switching the wires to TPS pins 1 and 3 Section 5B EFI Fuel System Fuel System A WARNING Fuel System Under Pressure The fuel system operates under high pressure System pressure must be relieved through the test valve in the fuel rail prior to servicing or removing any fuel system components Do not smoke or work near heaters or other fire hazards Have a fire extinguisher handy and work only in a well ventilated area The function of the fuel system is to provide sufficient delivery of fuel at the system operating pressure of 39 psi 3 If an engine starts hard or turns over but will not start it may indicate a problem with the EFI fuel system A quick test will verify if the system is operating 1 Disconnect and ground the spark plug leads 2 Complete all safety interlock requirements and crank the engine for approximately 3 seconds 3 Remove the spark plugs and check for fuel at the tips a If there is fuel at the tips of the spark plugs the fuel pump and injectors are operating b If there is no fuel at the tips of the spark plugs check the following 1 Make sure the fuel tank contains clean fresh proper fuel 2 Make sure that vent in fuel tank is open 3 Make sure fuel tank valve if so e
57. cylinders a special patented nickel silicone plating process for increased power superior oil control reduced exhaust emission and virtually permanent cylinder life POWER BORE cylinders cannot be resized or honed as described in the following procedure If a plated cylinder bore is damaged or out of specification use a new miniblock or short block to repair the engine Use the following procedure for crankcases with a cast iron sleeve Honing While most commercially available cylinder hones can be used with either portable drills or drill presses the use of a low speed drill press is preferred as it facilitates more accurate alignment of the bore in relation to the crankshaft crossbore Honing is best accomplished at a drill speed of about 250 RPM and 60 strokes per minute After installing coarse stones in hone proceed as follows 1 Lower hone into bore and after centering adjust so the stones are in contact with the cylinder wall Use of a commercial cutting cooling agent is recommended 2 With the lower edge of each stone positioned even with the lowest edge of the bore start drill and honing process Move the hone up and down while resizing to prevent the formation of cutting ridges Check the size frequently Section 10 Inspection and Reconditioning NOTE Kohler pistons are custom machined to exacting tolerances When oversizing a cylinder it should be machined exactly 0 25 mm 0 010 in or 0 50 mm 0 020 in
58. disconnect to prevent deterioration If you choose to the battery or use a battery minder to keep the use a Stabilizer follow the manufacturer s battery charged during storage recommendations and add the correct amount for the capacity of the fuel system 6 Store the engine in a clean dry place 1 5 Section 1 Safety and General Information Dimensions in millimeters Inch equivalents shown in 14 77 14 77 582 sez ALTERNATE OIL 60 00 AIR CLEANER FILL LOCATION 2 362 COVER REMOVAL 470 86 18 538 FUEL FILTER SOLENOID SHIFT STARTER 15 70 42 04 92 10 4X 10 30 408 rei Bees Iss p m MOUNTING HOLES LIFTING STRAP DIL FILTER T ENGINE MI REMOVAL 185 15 4 E Kona E MOUNTING 7 250 pesos munus HOLE A a z SPARK ADVANCE E 468 28 MODULE STANDARD 18 436 ON SOME MODELS 20 28 HP 456 58 17 876 113 20 LIB HP 4 457 20 28 HP MECHAN I CAL 101 50 FUEL PUMP 3 996 18 HP 8 525 3 51 S0 KEYWAY 20 28 HP 6 350 250 SQ KEYWAY 18 HP 2X OIL DRAIN PLUG m 3 8 N P T INCH sin MOUNTING HOLE A 3 504 287 09 11 303 5 6 18 UNF 2B 38 10 11 500 DEEP 20 28 HP OIL COOLER S 7 16 20 UNF 2B 4 00 eene E JS Pat 38 10 1 500 DEEP 557 100 00 x PR d AS S 3 i 3 504 30 NY Ass MOUNT ING ako D SURFACE 4d EN J E AN Z MOUNTING HOLE A 275 TANN n was AMANT di Y A NAE tl as T M 3 8 16 UNC 2B INCH
59. disconnect ALL external loads from engine belts pumps electric PTO clutch alternator rectifier regulator etc 3 Start the engine and allow it to warm up for 5 10 minutes so oil temperature is above 55 C 130 F Move the throttle control to the idle position and allow engine to stabilize for a minimum of one minute 5 Install a heavy rubber band around the throttle lever and the manifold boss to firmly hold the throttle against the idle stop On some EFI engines there is a dampening spring on the end of the idle speed screw The dampening spring if used should be fully compressed and the tab on the throttle lever in direct contact with the speed screw Adjust the idle speed to 1500 RPM using a tachometer 6 Shut off engine 7 Locate the service connector plug in the wiring harness 35 Pin MA 1 7 Metal Cased ECU Connect a jumper wire from the TPS initialization pin 8 gray wire to the ground pin black wire or use the jumper plug with the red jumper wire See Figure 5B 8 Section 5B EFI Fuel System 24 Pin MSE 1 0 Plastic Cased ECU Connect b If light stays on or blinking ceases a jumper wire from the TPS initialization pin 24 prematurely the procedure was unsuccessful violet wire to the battery voltage pin red wire and must be repeated Possible causes for or use the jumper plug with the blue jumper unsuccessful learning may be 1 Movement wire See Figure 5B 9 occurred in eithe
60. from the engine connector Rejoin the connectors and position or insulate the kill lead terminal so it cannot touch ground Try to start the engine to verify whether the reported problem is still present a Ifthe problem is gone the electrical system on the unit is suspect Check the key switch wires connections safety interlocks etc b If the problem persists the condition is associated with the ignition or electrical system of the engine Leave the kill lead isolated until all testing is completed NOTE If the engine starts or runs during any of 2 8 6 the testing you may need to ground the kill lead to shut it down Because you have interrupted the kill circuit it may not stop using the switch Test for spark on both cylinders with Kohler ignition tester see Section 2 Disconnect one spark plug lead and connect it to the post terminal of the tester Connect the clip to a good eround not to the spark plug Crank the engine and observe the tester spark gap Repeat the procedure on the other cylinder Remember to reconnect the first spark plug lead a If one side is not firing check all wiring connections and terminations on that side If wiring is okay replace ignition module and retest for spark b Ifthe tester shows spark but the engine misses or won t run on that cylinder try a new spark plug c If neither side is firing recheck position of ignition switch and check for shorted kill lead
61. high pressure 10 15 micron in line fuel filter Figure 5B 32 In Line Fuel Filter Service Fuel filter replacement is recommended every 1500 hours of operation or more frequently under extremely dusty or dirty conditions Use only the specified filter and install it according to the directional arrows Do not use a substitute filter as operating performance and safety can be affected Relieve system pressure through the safety valve in the fuel rail before servicing Fuel Rail Fuel Rail i 4 3 Locking Clip Fuel Injector Figure 5B 33 Manifold Assembly 9B 22 General The fuel rail is a formed tube assembly that feeds fuel to the top of the injectors The tops of the injectors fit into formed cups in the fuel rail When the rail is fastened to the manifold the injectors are locked into place A small retaining clip provides a secondary lock Incorporated into the fuel rail is a pressure relief test valve for testing operating pressure or relieving fuel system pressure for servicing The fuel supply line is attached to the barbed end of the fuel rail with an Oetiker hose clamp Service The fuel rail is mounted to the throttle body intake manifold It can be detached by removing the two mounting screws and the injector retaining clips Thoroughly clean the area around all joints prior to any disassembly No specific servicing is required unless operating conditions indicate that it needs internal clean
62. housing is removed Figure 9 33 Removing the Spark Advance Module Applicable Models 4 Remove the three each side hex flange screws securing the outer baffles Note the location of any lifting strap and position of the two short screws one each side on bottom for reassembly See Figure 9 34 Figure 9 36 Removing Metal Grass Screen 7 Remove the lower blower housing screw and washer securing the rectifier regulator ground lead or grounding strap 8 Two Barrel Carburetor Models Only Remove the two screws securing the debris shield to the blower housing The wiring harness is attached to the underside of shield See Figure 9 37 Figure 9 34 Note Location of Two Short Screws 9 9 Section 9 Disassembly Debris Shield Mounting Screws iz s 4 i E M N 4 i i m m i Y PF a _ 2 mm cual z Figure 9 37 Debris Shield Details Two Barrel Figure 9 39 Removing Fasteners Holding Baffle Carburetor Model Shown and Breather Cover 9 Remove the remaining hex flange screws and 2 Remove both inner baffles See Figure 9 40 detach the blower housing See Figure 9 38 10 Disconnect the plug from the key switch in the blower housing if engine is so equipped 3 Remove the two remaining screws holding the breather cover to the crankcase See Figure 9 40 Figure 9 38 Removing Blower Housing 4 Pry under the protruding edge of the breather Remov
63. inlet needle See Remedy 2e Bowl vents plugged Blow out with compressed air Carburetor bowl gasket leaks Replace gasket Troubleshooting Checklist When the engine starts hard runs roughly or stalls at low idle speed check the following areas before adjusting or disassembling the carburetor e Make sure the fuel tank is filled with clean fresh gasoline e Make sure the fuel tank cap vent is not blocked and that it is operating properly e Make sure fuel is reaching the carburetor This includes checking the fuel shut off valve fuel tank filter screen in line fuel filter fuel lines and fuel pump for restrictions or faulty components as necessary e Make sure the air cleaner base and carburetor are securely fastened to the engine using gaskets in good condition e Make sure the air cleaner element including precleaner if equipped is clean and all air cleaner components are fastened securely e Make sure the ignition system governor system exhaust system and throttle and choke controls are operating properly If the engine is hard starting runs roughly or stalls at low idle speed it may be necessary to adjust or service the carburetor High Altitude Operation Operating the engine with the wrong engine configuration at a given altitude may increase its emissions and decrease fuel efficiency and performance To ensure correct engine operation at altitudes above 1219 meters 4000 ft it may be necessary to
64. is applied the charging system is OK and battery was fully charged Trace B lead from rectifier regulator to key switch or other accessible connection Disconnect it from switch or connection Connect an ammeter from loose end of B lead to positive terminal of battery Connect DC voltmeter from loose end of B lead to negative terminal of battery With engine running at 3600 RPM read voltage on voltmeter If voltage is less than 13 8 or charge rate does not increase when load is applied test stator Tests 2 and 3 If voltage is 13 8 volts or more place a minimum load of 5 amps on battery to reduce voltage Observe ammeter NOTE Turnon lights if 60 watts or more Or place a 2 5 ohm 100 watt resistor across battery terminals No Charge Remove connector from rectifier regulator If voltage is 28 volts or more stator is OK to Battery With engine running at 3600 RPM measure Rectifier regulator is faulty Replace the AC voltage across stator leads using an AC rectifier regulator voltmeter If voltage is less than 28 volts stator is probabl faulty and should be replaced Test stator further using an ohmmeter Test 3 With engine stopped measure the resistance Tf resistance is 0 064 0 2 ohms the stator is OK across stator leads using an ohmmeter If the resistance is infinity ohms stator is open Replace stator With the engine stopped measure the Ifthe resistance is infinity ohms
65. mode is referred to as closed loop operation The EFI system operates closed loop when all three of the following conditions are met a The oil temperature is greater than 35 C 95 F b The oxygen sensor has warmed sufficiently to provide a signal minimum 375 C 709 F c Engine operation is at a steady state not starting warming up accelerating etc During closed loop operation the ECU has the ability to readjust temporary and learned adaptive controls providing compensation for changes in overall engine condition and operating environment so it will be able to maintain the ideal air fuel ratio of 14 7 1 The system requires a minimum engine oil temperature greater than 55 C 130 F to properly adapt These adaptive values are maintained as long as the ECU is powered up by the battery 5B 3 Section 5B EFI Fuel System During certain operating periods such as cold starts warm up acceleration etc an air fuel ratio richer than 14 7 1 is required and the system operates in an open loop mode In open loop operation the monitoring of exhaust gases output is not used and the controlling adjustments are based on the primary sensor signals and programmed maps only The system operates open loop whenever the three conditions for closed loop operation above are not being met Important Service Notes e Cleanliness is essential and must be maintained at all times when servicing or working on
66. necessary or use a C clamp to hold the pulley in position 9 Insert the new rope through the rope hole in the starter pulley and the rope guide bushing of the housing See Figure 7 3 7 2 p D Ro pe i Guide Bushing Figure 7 3 Installing Rope 10 11 12 Tie a slipknot approximately 12 in from the free end of rope Hold the pulley firmly and allow it to rotate slowly until the slipknot reaches the guide bushing of the housing Slip the handle and rope retainer onto the rope Tie a single knot at the end of the rope Install the rope retainer into the starter handle Untie the slipknot and pull on the handle until the rope is fully extended Slowly retract the rope into the starter When the spring is properly tensioned the rope will retract fully and the handle will stop against the starter housing Pawls Dogs Replacement To replace the pawls follow disassembly steps 1 4 and reassembly steps 3 8 on the following pages A pawl repair kit is available which includes the following components ay Pawl Retainer Center Screw Pawl Dog Spring Brake Spring Starter Pawl Dog Brake Washer Washer Disassembly A WARNING Spring Under Tension Do not remove the center screw from the starter until the spring tension is released Removing the center screw before releasing spring tension or improper starter disassembly can cause the sudden and potentially dangerous release of the spring Follo
67. of the test cycle Otherwise a false reading may be displayed in the form of a or a faint 8 8 14 PRESS REPEATERIEY UNTIL CORRE TEST LI T5 DISPLATT Figure 8 16 Pass Indicator The tester is powered by a 9 volt battery Most SAMs are designed to operate down to a minimum of 7 25 volts If the tester battery drops below that level incorrect test readings will result The tester battery should be checked periodically by connecting a DC voltmeter between the red and green lead wires with the tester connected to a SAM Press and hold the test button for a full test cycle F or P appears and then display shuts off while monitoring the voltage reading on the voltmeter If the voltage drops below 7 5 at any time during the cycle the 9 volt tester battery must be replaced Use an extended life alkaline battery To replace the battery remove the outer set of screws on the faceplate and carefully lift the panel from the body Unplug the connector and pull battery with mounting tape off the back of the tester Attach the connector to the new battery and mount the battery to the case with double backed tape Reinstall the faceplate and secure with the four screws Section 8 Electrical System and Components C DSAI Ignition System Operation A digital spark advance ignition system DSAI is The system provides more consistent energy to the used on some models The DSAI ignition system is an
68. on the power switch See Figure 8 30 This does not represent the The POWER light should be illuminated and condition of the part one of the four status lights may be on as well See Figure 8 30 This does not represent the condition of the part 8 25 Section 8 Electrical System and Components 4 Press the TEST button until a click is heard and then release See Figure 8 31 Momentarily either the HIGH LOW or SHORT light will flash a If the HIGH light flashes on off the part is good and may be used b If any other light is displayed the rectifier is faulty and should not be used NOTE A flashing LOW light can also occur as a result of an inadequate ground lead connection Make certain connection location is clean and clamp is secure Rectifier Regulator Flywheel Stator Ammeter Figure 8 37 Connections for Testing Charging System 8 26 Section 8 Electrical System and Components Troubleshooting Guide 15 20 25 Amp Battery Charging Systems When problems occur in keeping the battery charged or the battery charges at too high a rate the problem can usually be found somewhere in the charging system or with the battery NOTE Always zero ohmmeter on each scale before testing to ensure accurate readings Voltage tests should be made with the engine running at 3600 RPM no load The battery must be good and fully charged 1 If voltage is 13 8 14 7 and charge rate increases when load
69. or wiring problem b Sensor contaminated or damaged c Sensor below the minimum operating temperature 375 C 709 F d Poor ground path from sensor to engine sensor grounds through shell see Oxygen Sensor section Code 33 Source Oxygen Sensor Fuel System Explanation System too rich Temporary fuel adaptation control is at the upper limit Expected Engine Response Erratic performance Will run rich smoke Possible Causes 1 Fuel Supply Related nothing lean only rich a Restricted return line causing excessive fuel pressure b Fuelinlet screen plugged in tank fuel pump only c Incorrect fuel pressure at fuel rail 2 Oxygen Sensor Related Sensor connector or wiring problem Sensor contaminated or damaged Exhaust leak Poor ground path Pin circuit wiring or connectors Pin 10 for 35 Pin MA 1 7 Metal Cased ECU Pin 11 for 24 Pin MSE 1 0 Plastic Cased ECU PRPP 5B 40 Pin 20 for 32 Pin MSE 1 1 Plastic Cased ECU 3 TPS Sensor Related a Throttle plate position incorrectly set or registered during Initialization b TPS problem or malfunction 4 Engine Wiring Harness Related a Difference in voltage between sensed voltage pin circuit 17 for metal cased ECU pin circuit 2 for plastic cased ECU and actual injector voltage circuit 45 45A 5 Systems Related a Ignition spark plug plug wire ignition coil b Fuel fuel type quality injector fuel pu
70. plug boot must be used to prevent electrical system noise The safety switches are to be wired in series with the power relay It is recommended that the ECU be mounted vertically with the wire bundle down or horizontally with the ALL Weather connector down It is recommended that the ECU housing be grounded to the chassis The ECU should not be mounted to the engine nor should it be powerwashed When not in operation the battery must maintain a minimum system voltage of 7 volts with a current draw of 20mA to maintain adaptive memory During a stort the battery must maintain 7 volts minimum system voltage for ECU operation during crank Unless otherwise specified ALL wires are 18 ANG Connector Ji PIN FUNCTION D Battery Supply Permanent 2 Switched Ignition 3 Saftey Switch 4 TPS amp Temp Ground 5 Not Used 6 Motor Temp Input 7 Spare A D Input 8 TPS input 9 VR Input 10 gt VR Input gt 1D Lambda Input 185 Lambda Ground i need 13 K Line 14 TPS Supply Voltage 15 Battery Ground 165 Injector 1 Dutput 175 Injector 8 Output 185 Pump Relay Output 19 Diag Lamp Output 20 Tach Output ep Spare output 22 Igni output 23 Igne output 24 EDL TPS set Battery Gnd See Grounding Note Jl Bi r T L o o y y V J1 9 agen XX Z See General Note 10 TPS Intlatization J1 24 J1 11 gt 1 O 2 Sensor Jes Speed Sensor Inductive Pick up See Groundi
71. rate must be 7 5 L hr 2 gal hr with a pressure at 0 3 psi and a fuel lift of 18 in from carburetor inlet A 1 3 L hr 0 34 gal hr fuel rate must be maintained at 5 Hz Fuel Pump Replacement Replacing the Pulse Fuel Pump Replacement pumps are available through your source of supply To replace the pulse pump follow these steps 1 Disconnect the fuel lines from the inlet and outlet fittings 2 Remove the hex flange screws securing the fuel pump 3 Remove the pulse line that connects the pump to the crankcase or valve cover Section 5 Fuel System and Governor NOTE On most models the pulse line is connected to a fitting on the crankcase while on early models it is connected to the valve cover 4 Install the new fuel pump using the hex flange screws Torque the hex flange screws to 2 3 N m 20 in Ib NOTE Make sure the orientation of the new pump is consistent with the removed pump Internal damage may occur if installed incorrectly 5 Connect the pulse line to the pulse fitting 6 Connect the fuel lines to the inlet and outlet fittings Replacing the Mechanical Pump The mechanical pump is an integral part of the valve cover assembly and not serviced separately See Figure 5 2 1 Disconnect the fuel lines from the inlet and outlet fittings 2 Follow the procedure for replacing the valve cover Sections 9 and 11 3 Reconnect the fuel lines to the inlet and outlet fittings
72. recoil spring at this time Housing Figure 7 8 Installing Pulley and Spring into Housing 3 Install the pawl springs and pawls into the starter pulley See Figure 7 9 Section 7 Retractable Starter 4 Place the brake washer in the recess in starter 7 Tension the spring and install the rope and pulley over the center shaft handle as instructed in steps 6 through 12 under Rope Replacement on page 7 2 5 Lubricate the brake spring sparingly with grease Place the spring on the plain washer 8 Install the starter to the engine blower housing Make sure the threads in the center shaft remain as instructed in To Install Starter on page 7 1 clean dry and free of grease and oil 6 Apply a small amount of Loctite No 271 to the threads of the center screw Install the center screw with the washer and retainer to the center shaft Torque the screw to 7 4 8 5 N m 65 75 in Ib 7 5 Section 7 Retractable Starter 7 6 Section 8 Electrical System and Components This section covers the operation service and repair NOTE Do not clean spark plug in a machine of the electrical system components Systems and using abrasive grit Some grit could components covered in this section are remain in the spark plug and enter the engine causing extensive wear and e Spark Plugs damage e Battery and Charging System e Electronic Ignition Systems CD and DSAI 3 Check the gap using a wire feeler gauge Adjust
73. relates to this type starter also so it is not repeated here A Nippondenso or Delco Remy solenoid shift starter may be used The Nippondenso starter is covered first and the Delco Remy starter servicing follows Operation Solenoid Shift Starter When power is applied to the starter the electric solenoid moves the drive pinion out onto the drive shaft and into mesh with the flywheel ring gear When the pinion reaches the end of the drive shaft it rotates the flywheel and cranks the engine When the engine starts and the start switch is released the starter solenoid is deactivated the drive lever moves back and the drive pinion moves out of mesh with the ring gear into the retracted position Front Stop Collar e e Retainer Rear Stop Collar Insulator Commutator Thru Bolt Section 8 Electrical System and Components Starter Disassembly Starter Service 1 Disconnect the lead wire from the solenoid Every 500 hours of operation or annually whichever comes first solenoid shift starters must be 2 Remove the hex nuts securing the solenoid and disassembled cleaned and relubricated Apply starter remove the solenoid from the starter assembly lubricant see Section 2 to the lever and shaft Failure to do so could result in an accumulation of dirt or 3 Remove the two thru bolts debris that might prevent the engine from starting and could cause damage to the starter or the flywheel 4 Remove the co
74. remove any accumulated deposits See Figure 5A 23 Regulator Drain Plug Figure 5A 23 Regulator Drain Plug Some Models 1 Turn supply valve off run engine out of fuel and turn off ignition switch 2 Disconnect and ground the spark plug leads 3 Remove the 1 8 pipe plug from bottom of regulator and drain any accumulated deposits See Figure 5A 23 4 Reinstall plug using pipe sealant with Teflon Loctite 592 or equivalent on threads and tighten securely If required a replacement plug is available as Kohler Part No X 75 23 S 5A 12 Regulator Service Every 1500 hours it is recommended that disassembly cleaning and resetting of the regulator be performed using the regulator rebuilding kit available Specific instructions are included in the rebuilding kit Perform the regulator service following the instructions provided As all adjustments and settings must be reset using specific test equipment this must be performed by qualified LP personnel only Impco Beam Regulator Service Kohler repair kit 24 757 40 5 should be used to service the regulator every 1500 hours or whenever cleaning and servicing is required Nikki Regulator Service Kohler repair kit 24 757 39 5 should be used every 1500 hours Section 5B Electronic Fuel Injection EFI Fuel System Contents Page s Description IxrDabotasDpbo Prane Proce dUT nee aieeao iink NE EEEE EAEEREN E EN E EEEE Mrd 5B 2 A OC O a ood E A E A etna E
75. rings when installing pistons Never use old rings Some important points to remember when servicing piston rings 1 The cylinder bore must be deglazed before service ring sets are used 2 If the cylinder bore does not need reboring and if the old piston is within wear limits and free of score or scuff marks the old piston may be reused 3 Remove the old rings and clean up the grooves Never reuse old rings 4 Before installing the new rings on the piston place the top two rings each in turn in its running area in the cylinder bore and check the end gap See Figure 10 9 Compare the ring gap to the specifications listed in Section 1 Figure 10 9 Measuring Piston Ring End Gap 5 After installing the new compression top and middle rings on the piston check the piston to ring side clearance Compare the clearance to specifications listed in Section 1 If the side clearance is greater than specified a new piston must be used Refer to Figure 10 10 10 10 Figure 10 10 Measuring Piston Ring Side Clearance Install New Piston Rings To install new piston rings proceed as follows NOTE Rings must be installed correctly Ring installation instructions are usually included with new ring sets Follow instructions carefully Use a piston ring expander to install rings see Figure 10 11 Install the bottom oil control ring first and the top compression ring last Refer to Figure 10 12 Piston Ri
76. routed side by side especially under a single clamp there must be a small gap between the cables to prevent internal binding After the high speed setting has been completed check that there is a gap of at least 0 5 mm 0 020 in between the control cables Throttle Control Lever 2 Choke Control Lever 1 Choke Control Cable Kill Switch Throttle Control Cable Kill Switch Adjusting Screw Dual Control High Speed Lever Stop Screw Do Not Remove High Speed Adjusting Screw Figure 5 40 Governor Control Connections 5 22 Choke Linkage Z Bend Throttle Control Cable 0O High Speed Control Lever Right Side Pull Section 5 Fuel System and Governor Electronic Governor Digital Linear Actuator DLA Energizing the bi directional digital linear actuator General coils in the proper sequence causes the threaded shaft The electronic governor regulates engine speed at to move out of or back into the rotor in precise linear varying loads It consists of a governor control unit increments When power is removed the actuator digital linear actuator and linkage shaft remains in position The DLA must initialize fully extend to move the throttle plate to the closed position and partially open for starting Correct adjustment of the DLA is critical to achieve the full range of throttle plate movement See Adjustment Procedure Governor Control Unit GCU senses engine speed by pulse voltage inp
77. setting is 17 mm 0 669 in 1 5 mm 0 059 in measured from the float bottom to the body of the carburetor See Figure 5 19 Replace the float if the height is different than the specified setting DO NOT attempt to adjust by bending float tab Figure 5 19 Checking Float Height NOTE Be sure to measure from the casting surface not the rubber gasket if still attached Section 5 Fuel System and Governor 9 When the proper float height is obtained NOTE Further disassembly of the fuel bowl is not carefully reinstall the fuel bowl using new necessary unless the Fuel Solenoid Kit or O Rings onto the carburetor Secure with the four Fuel Bowl Kit obtained separately will also original screws Torque the screws to 2 5 0 3 be installed N m 23 2 6 in Ib See Figure 5 20 2 Remove the float pin screw and lift out the old float pin and inlet needle See Figure 5 22 Discard all the old parts The seat for the inlet needle is not serviceable and should not be removed Figure 5 20 Installing Fuel Bowl 10 Install the carburetor and the heavy duty air cleaner as outlined in Section 11 Reassembly Disassembly Overhaul 1 Clean the exterior surfaces of dirt or foreign material before disassembling the carburetor Remove the four mounting screws and separate the fuel bowl from the carburetor Transfer any remaining fuel into an approved container Remove and discard the old O Rings Fuel can als
78. shaft bushing with the old choke lever from the carburetor housing Save the bushing to use as a driver for installing the new bushing Discard the old lever Clean the I D of both choke shaft bores as required Insert the new bushing through the new choke lever from the outside and start the bushing in the outer shaft bore Position the choke lever so the protruding boss on the carburetor housing is between the two stops formed in the choke lever See Figure 5 33 Figure 5 33 Assembling Choke Lever 8 Turn the old bushing upside down and use it as a driver to carefully press or tap the new bushing into the carburetor body until it bottoms Check that the choke lever pivots freely without restriction or binding See Figure 5 34 Figure 5 34 Installing Bushing 9 Install the new return spring onto the new choke shaft so the upper leg of the spring is between the two formed stops on the end of the choke shaft See Figure 5 35 NOTE Make sure it stays in this location during the following step Figure 5 35 Choke Shaft and Spring Details 10 11 Slide the choke shaft and spring into the carburetor Pivot preload the shaft and set the inner leg of the spring against the formed stop within the choke lever as originally assembled See Figure 5 32 The opposing leg of the spring must still be between the formed stops of the choke shaft Place a drop of Loctite on the threads of each new s
79. side Pivot the carburetor to clear the breather cover fitting and pressure switch if equipped Remove the carburetor throttle linkage choke linkage and the governor lever as an assembly E Figure 9 25 Removing Governor Lever Remove Carburetor A WARNING Explosive Fuel Gasoline is extremely flammable and its vapors can explode if ignited Store gasoline only in approved containers in well ventilated unoccupied buildings away from sparks or flames Do not fill the fuel tank while the engine is hot or running L i f E 1 M P a i b er Li p s ET h KE 7 2d v i since spilled fuel could ignite if it comes in contact with hot Figure 9 27 Removing Carburetor Mounting parts or sparks from ignition Do not start the engine near Screws spilled fuel Never use gasoline as a cleaning agent rn 3 Remove the carburetor throttle linkage and 1 Disconnect the fuel shut off solenoid lead and governor lever as an assembly See Figure 9 28 ground lead if equipped See Figure 9 26 Ground Lead Figure 9 28 Removing Carburetor Assembly with Governor Lever Attached Model Pictured 4 Remove the carburetor gasket 9 7 Section 9 Disassembly 5 If necessary the carburetor throttle linkage and Remove Outer Baffles and Blower governor lever can be separated Reattach the Housing bushings to the linkage following separation to 1 Disconnect the plug from the rectifier r
80. spark plugs at all engine speeds by using the 12 volt advanced 12 volt version of the fixed timing ignition battery as its source of power Engine speed and top system used on other models Two inductive style dead center TDC location reference information ignition modules control the ignition timing based on is provided by the flywheel magnet group as it engine RPM A typical DSAI application Figure 8 17 passes the ignition module System triggering and consists of the following components engine timing is performed by a digitally controlled microprocessor This digital control provides e Amagnet assembly which is permanently affixed repeatable and consistent engine cylinder spark to the flywheel timing Each DSAI module performs its function independently for each engine cylinder e Two inductive 12 volt ignition modules which mount on the engine crankcase Figure 8 17 e A 12 volt battery which supplies current to the ignition modules e Akill switch or key switch which grounds the spark advance module to stop the engine e Two spark plugs Key Switch or Off Position of Key Switch on 12 Volt Battery Spark an Plug magnet Ignition keg Paes Modules Figure 8 17 Digital Spark Advance Ignition DSAI System 8 15 Section 8 Electrical System and Components Troubleshooting DSAI Ignition Systems The DSAI ignition system is designed to be trouble free for the life of the engine Other
81. starting or loss of power accompanied by high fuel consumption may be symptoms of faulty valves Although these symptoms could also be attributed to worn rings remove and check the valves first After removal clean the valve heads faces and stems with a power wire brush Section 10 Inspection and Reconditioning INTAKE VALVE EXHAUST INSERT INTAKE INSERT Insert O D 36 987 37 013 mm 1 4562 1 4572 in 32 987 33 013 mm 1 2987 1 2997 in 6 5 mm 0 2559 in Guide I D 7 038 7 058 mm 0 2771 0 2779 in 7 038 7 058 mm 0 2771 0 2779 in Valve Head Diameter 33 37 33 63 mm 1 3138 1 3240 in 29 37 29 63 mm 1 1563 1 1665 in 45 1 5 mm 0 0591 in Valve Stem Diameter 6 982 7 000 mm 0 2749 0 2756 in 6 970 6 988 mm 0 2744 0 2751 in Then carefully inspect each valve for defects such as a warped head excessive corrosion or a worn stem end Replace valves found to be in bad condition A normal valve and valves in bad condition are shown in the accompanying illustrations 10 5 Section 10 Inspection and Reconditioning Normal Even after long hours of operation a valve Leakage A poor grind on face or seat of valve will can be reconditioned and reused if the face and allow leakage resulting in a burned valve on one side margin are in good shape If a valve is worn to where only the margin is less than 1 32 do not reuse it The valve shown was in operation for almost 1000 hours under controlled test
82. than periodically checking replacing the spark plugs no maintenance timing or module adjustments are necessary or possible Mechanical systems do occasionally fail or break down however so the following troubleshooting information is provided to help you get to the root of a problem Reported ignition problems are most often due to poor connections Before beginning the test procedure check all external wiring Be certain all ignition related wires are connected including the spark plug leads Be certain all terminal connections fit snugly Make sure the ignition switch is in the RUN position Test Procedure for DSAI Ignition Systems The following procedures are provided for troubleshooting ignition problems on DSAI equipped engines They will allow you to isolate and pinpoint the failed component s Special Tools Required e Hand Tachometer e Ignition Tester Kohler Part No 25 455 01 S e Automotive Timing Light e Multi meter Digital Specifications Required e Spark plug gap 0 76 mm 0 030 in NOTE Ignition tester Kohler Part No 25 455 01 5 must be used to test ignition on these engines Use of any other tester can result in inaccurate findings The battery on the unit must be fully charged and properly connected before making any of these tests a battery that is hooked up or charged backward will crank the engine but it won t have spark Be certain the drive is in neutral and all external loads are dis
83. the instructions provided with the valve seat cutter being used A typical cutter is shown in Figure 10 7 The final cut should be made with an 89 cutter as specified for the valve seat angle in Figure 10 6 Cutting the proper 45 valve face angle as specified in Figure 10 6 and the proper valve seat angle 44 5 half of the full 89 angle will achieve the desired 0 5 1 0 full cut interference angle where the maximum pressure occurs on the outside diameters of the valve face and seat 10 8 Valve Seat Cutter Figure 10 7 Typical Valve Seat Cutter Lapping Valves Reground or new valves must be lapped in to provide proper fit Use a hand valve grinder with a suction cup for final lapping Lightly coat the valve face with a fine grade of grinding compound then rotate the valve on its seat with the grinder Continue grinding until a smooth surface is obtained on the seat and on the valve face Thoroughly clean the cylinder head in soap and hot water to remove all traces of grinding compound After drying the cylinder head apply a light coating of SAE 10 oil to prevent rusting Intake Valve Stem Seal These engines use valve stem seals on the intake valves Always use a new seal when the valves are removed from the cylinder head The seals should also be replaced if deteriorated or damaged in any way Never reuse an old seal Pistons and Rings Inspection Scuffing and scoring of pistons and cylinder walls occurs wh
84. the pump preventing the continued delivery of fuel In this situation the MIL will go on but it will go back off after 4 cranking revolutions if system function is OK Once the engine is running the fuel pump remains on Service The fuel pumps are non serviceable and must be replaced if determined to be faulty If a fuel delivery problem is suspected make certain the pump is being activated through the relay all electrical connections are properly secured the fuses are good and a minimum of 7 0 volts is being supplied If during cranking voltage drops below 7 0 volts a reduction of fuel pressure may occur resulting in a lean starting condition If required testing of the fuel pump and relay may be conducted 5B 19 Section 5B EFI Fuel System 1 Connect the black hose of Pressure Tester part of EFI Service Kit see Section 2 to the test valve in the fuel rail Route the clear hose into a portable gasoline container or the equipment fuel tank 2 Turn on the key switch to activate the pump and check the system pressure on the gauge If system pressure of 39 psi 3 is observed the relay fuel pump and regulator are working properly Turn the key switch off and depress the valve button on the tester to relieve the system pressure a Ifthe pressure is too high and the regulator is outside the tank just down line from the pump check that the return line from the regulator to the tank is not kinked or blocked
85. the EFI system Dirt even in small quantities can cause significant problems e Clean any joint or fitting with parts cleaning solvent before opening to prevent dirt from entering the system e Always depressurize the fuel system through the test valve in fuel rail before disconnecting or servicing any fuel system components See fuel warning on page 5B 2 e Never attempt to service any fuel system component while engine is running or ignition switch is on e Do not use compressed air if the system is open Cover any parts removed and wrap any open joints with plastic if they will remain open for any length of time New parts should be removed from their protective packaging just prior to installation e Avoid direct water or spray contact with system components e Do not disconnect or reconnect the wiring harness connector to the control unit or any individual components with the ignition on This can send a damaging voltage spike through the ECU e Do not allow the battery cables to touch opposing terminals When connecting battery cables attach the positive cable to positive battery terminal first followed by negative cable to negative battery terminal e Never start the engine when the cables are loose or poorly connected to the battery terminals 5B 4 e Never disconnect battery while engine is running e Never use a quick battery charger to start the engine e Do not charge battery with
86. the center power red lead terminal of the DSAI module Use the same ground location for the multi meter as in Step 3 a If all tests are OK and module has no spark or fails to advance replace the affected module b Ifany of the tests are bad determine cause and fix as required then retest 8 17 Section 8 Electrical System and Components Battery Charging System General Most engines are equipped with a 15 or 20 amp regulated charging system Some have a 25 amp regulated charging system See Figures 8 23 8 24 and 8 25 for the 15 20 25 amp charging system diagrams Some engines utilize a 3 amp unregulated system with optional 70 watt lighting circuit Refer to Figure 8 26 NOTE Observe the following guidelines to avoid damage to the electrical system and components e Make sure the battery polarity is correct A negative ground system is used e Disconnect the rectifier regulator plug and or the wiring harness plug before doing any electric welding on the equipment powered by the engine Also disconnect all other electrical accessories in common ground with the engine e Prevent the stator AC leads from touching or shorting while the engine is running This could damage the stator 15 20 25 Amp Regulated Charging System Figure 8 20 15 Amp Stator and Rectifier Regulator Figure 8 21 20 Amp Stator and Rectifier Regulator 1st Style 25 Amp Stator 2nd Style Figure 8 22 25 Amp Stator and Rectifier R
87. the lower end of the rod shank Always refer to the appropriate parts information to ensure that correct replacements are used Hydraulic Lifters Inspection Check the base surface of the hydraulic lifters for wear or damage If the lifters need to be replaced apply a liberal coating of Kohler lubricant see Section 2 to the base of each new lifter before it is installed Bleeding the Lifters To prevent a possible bent push rod or broken rocker arm it is important to bleed any excess oil out of the lifters before they are installed 1 Cuta 50 75 mm 2 3 in piece from the end of an old push rod and chuck it in a drill press 2 Lay arag or shop towel on the table of the drill press and place the lifter open end up on the towel 3 Lower the chucked push rod until it contacts the plunger in the lifter Slowly pump the plunger two or three times to force the oil out of the feed hole in the side of the lifter Closure Plate Assembly Inspection Inspect the oil seal in the closure plate and remove it if it is worn or damaged Refer to Install Closure Plate Oil Seal in Section 11 for new oil seal installation Inspect the main bearing surface for wear or damage refer to Section 1 Specifications Tolerances and Special Torque Values Replace the closure plate assembly if required Governor Gear Assembly Inspection Inspect the governor gear teeth Replace the gear if it is worn chipped or
88. the spark plug lead wire from module always away trom the cylinder On 1 cylinder the single kill tab should be towards you See Figure 11 54 On 2 cylinder the single kill tab should be away from you in Install each ignition module to the crankcase bosses with the two screws hex flange or allen head based on model Slide the modules up as far away from the flywheel as possible and snug the screws to hold them in that position Rotate the flywheel to position the magnet directly under one ignition module Insert a 0 30 mm 0 012 in flat feeler gauge between the magnet and the ignition module See Figure 11 50 Loosen the screws enough to allow the magnet to pull the module down against the feeler gauge Figure 11 50 Setting Ignition Module Air Gap 6 i Torque the screws to 4 0 6 2 N m 35 55 in Ib Repeat steps 4 through 6 for the other ignition module Rotate the flywheel back and forth checking for clearance between the magnet and ignition modules Make sure the magnet does not strike the modules Check the gap with a feeler gauge and readjust if necessary Final air gap 0 280 0 330 mm 0 011 0 013 in Install Intake Manifold ih Install the intake manifold and new gaskets or O Rings plastic manifold with wiring harness attached to the cylinder heads Slide any wiring harness clips onto the appropriate bolts before installing Make sure the gaskets are in the proper orientation Torqu
89. throttle plate angle to the ECU Since the throttle by way of the governor reacts to engine load the angle 55 Pin MA 1 7 Metal Cased ECU Red of the throttle plate is directly proportional to the load positive ohmmeter lead to 12 pin terminal on the engine and Black negative ohmmeter lead to 27 pin terminal 24 Pin MSE 1 0 Plastic Cased ECU Red positive ohmmeter lead to 8 pin terminal and Black negative ohmmeter lead to 4 pin terminal 32 Pin MSE 1 1 Plastic Cased ECU Red positive ohmmeter lead to 8 pin terminal pa and Black negative ohmmeter lead to 4 pin Mounted Throttle T A terminal Position Sensor Hold the throttle closed and check the resistance It should be 800 1200 Q Figure 5B 7 TPS Location 5B 7 Section 5B EFI Fuel System 4 Leave the leads connected to the pin terminals as described in step 3 Rotate the throttle shaft slowly counterclockwise to the full throttle position Monitor the dial during rotation for indication of any momentary short or open circuits Note the resistance at the full throttle position It should be 1800 3000 Q 5 Disconnect the main wiring harness connector from the TPS leaving the TPS assembled to the manifold Refer to the chart below and perform the resistance checks indicated between the terminals in the TPS switch with the throttle in the positions specified Throttle Between Resistance Closed 800 1200 Closed 1800 3000 Full
90. touch wires while engine is running Electrical Shock Never touch electrical wires or components while the engine is running They can be sources of electrical shock Engine Identification Numbers When ordering parts or in any communication involving an engine always give the Model Specification and Serial Numbers including letter suffixes if there are any The engine identification numbers appear on a decal or decals affixed to the engine shrouding See Figure 1 1 An explanation of these numbers is shown in Figure 1 2 A Model No Command Engine Horizontal Crankshaft Horsepower 17 17 HP 18 18 HP 20 20 HP 22 22HP 23 23 HP 25 25 HP 26 26 HP B Spec No Variation of Engine Model Code Basic Engine Model CH18 CH20 CH22 624 cc CH25 CH22 23 674 cc CH26 Serial No 3305810334 Year Manufactured Code Year Year 1991 2000 1992 2001 1993 2002 1994 2003 1995 2004 1996 2005 1997 2006 1998 2007 1999 2008 Section 1 Safety and General Information S Electric Start Numerical Designation 730 740 745 750 CH620 0001 CH640 0001 CH670 0001 CH680 0001 CH730 0001 CH735 0001 CH740 0001 CH745 0001 CH750 0001 Complete Spec Number Incorporating Model No with Variation No of Basic Spec Factory Code Code 39 40 Figure 1 2 Explanation of Engine Identification Numbers 1 3 Section 1 Safety and General Information Oil Recommendations Using the pro
91. vi EE E EEE 6 8 N m 60 in Ib Section 1 Safety and General Information Ignition Spark Plug Type Champion or Equivalent esce RC12YC XC12YC or Platinum 3071 Spark Plug Gap All except Natural Gas with CD Fixed Ij tiblobio asiento rit acea t eu aste miss 0 76 mm 0 030 in Natural Gas with CD Fixed Toni Ottiisssscsszssctsscnishesssnsestiinsansneainednieansesauinesnunens 0 51 mm 0 020 in Ui ie TS PO CS E P r 24 4 29 8 N m 18 22 ft Ib Ioyntion Module ATE GOD sireeni ae cron d Rabe ie 0 28 0 33 mm 0 011 0 013 in Ieeinon Module Fastener Tore saieieeta er behectateni Fassa e quA E MERE dad Eee 4 0 6 2 N m 35 55 in Ib Speed Sensor Air Gap EFLEDE INES uassibeitanesekhscesienisandunSendbi ned aedis eut od icta up subbeupS 1 50 0 25 mm 0 059 0 010 in Muffler Dares Retaining INE TOPCOBG eenen URN QU bd coker eatdenvauensnensinadenaes 24 4 N m 216 in Ib Cil Filter O Piter EO TC c TE P refer to oil filter for instructions Oil Cooler Ole golepZdapter pe DOPEUD usce sedi nio at Rud iau rete ecm ie eie 27 N m 20 ft Ib Piston Piston Rings and Piston Pin Piston to Piston Pin Running Clearance eee esee 0 006 0 017 mm 0 0002 0 0007 in Piston Pin Bore I D M n 17 006 17 012 mm 0 6695 0 6698 in Max Wear Els C c 17 025 mm 0 6703 in Piston Pin O D i
92. volt Test Leads Connect Only Long Enough to Test Figure 8 80 Testing Hold In Coil Function Test Test 4 Solenoid Hold In Coil Contact Continuity Test Use an ohmmeter set to the audible or Rx2K scale and connect the two ohmmeter leads to the two large post terminals Perform the preceding test 3 and check for continuity See Figure 8 81 The meter should indicate continuity if no continuity is indicated the solenoid should be replaced Repeat test several times to confirm condition Section 8 Electrical System and Components Plunger Pushed In 12 volt Test Leads Figure 8 81 Testing Hold In Coil Solenoid Contact Continuity 8 45 Section 8 Electrical System and Components 8 46 Section 9 Disassembly A WARNING Accidental Starts Disabling engine Accidental starting can cause severe injury or death Before working on the engine or equipment disable the engine as follows 1 Disconnect the spark plug lead s 2 Disconnect negative battery cable from battery General Clean all parts thoroughly as the engine is disassembled Only clean parts can be accurately inspected and gauged for wear or damage There are many commercially available cleaners that will quickly remove grease oil and grime from engine parts When such a cleaner is used follow the manufacturer s instructions and safety precautions carefully Make sure all traces of the cleaner are removed before the
93. well ventilated unoccupied buildings away from sparks or flames Do not fill the fuel tank while the engine is hot or running since spilled fuel could ignite if it comes in contact with hot parts or sparks from ignition Do not start the engine near spilled fuel Never use gasoline as a cleaning agent Pulse Style Pumps 1 Disconnect the fuel lines at the carburetor and at the in line fuel filter See Figure 9 15 Section 9 Disassembly 3 Remove the two hex flange screws securing the fuel pump to the bracket or to the blower housing See Figure 9 18 The fuel pump body may be metal or plastic Figure 9 15 Disconnecting Fuel Inlet Line at Carburetor 2 Figure 9 18 Removing Screws Holding Fuel Pump Metal Bodied Pump Shown 4 Note or mark the orientation of the fuel pump then remove the fuel pump with lines attached as shown in Figure 9 19 Figure 9 16 Disconnecting Pulse Line from Crankcase Figure 9 19 Remove Fuel Pump and Lines Mechanical Fuel Pump The mechanical style fuel pump is part of the valve cover assembly See Figure 9 20 1 Disconnect the fuel lines at the pump outlet and a lt at the in line fuel filter Figure 9 17 Disconnecting Pulse Line from Valve Cover Early Models 2 The fuel pump will be removed with the valve cover Refer to the valve cover removal 2 Disconnect the pulse vacuum line from the procedure crankcase or from the valve cover on earlier models See
94. with hot exhaust gt 2 UN parts 2 Install Fuel Pump Plastic Cased Pulse Fuel Pump Figure 11 75 Reinstalled Fuel Pump A WARNING Explosive Fuel Gasoline may be present in the carburetor and fuel system Gasoline is extremely flammable and its vapors can explode Install Carburetor if ignited Keep sparks and other sources of ignition awa i the pue i A WARNING Explosive Fuel Gasoline may be present in the carburetor and fuel system 1 Install the pulse style fuel pump and lines as an Gasoline is extremely flammable and its vapors can explode assembly Connect the pulse line to the crankcase if ignited Keep sparks and other sources of ignition away vacuum fitting or the valve cover whichever from the engine source is used One Barrel Carburetor Models NOTE Pulse style fuel pumps may be made of 1 Install a new carburetor gasket Make sure all n metal or plastic See Figure 11 75 If a holes align and are open new fuel pump is being installed make sure the orientation of the new pump 2 Install the carburetor throttle linkage and is consistent with the removed pump governor lever as an assembly See Figure 11 Internal damage may occur if installed 76 If a plastic intake manifold is used and the incorrectly carburetor is equipped with a fuel solenoid attach the ground lead to the carburetor 2 Install the fuel pump using the two hex flange mounting screw See Figure 11 77 screws Torque the screws to 2 3 N m
95. 1800 3000 Full 800 1200 Any 1600 2500 If the resistance values in steps 3 4 and 5 are within specifications go to step 6 If the resistance values are not within specifications or a momentary short or open circuit was detected during rotation step 4 the TPS needs to be replaced go to step 7 6 Check the TPS circuits input ground between the TPS plug and the main harness connector for continuity damage etc See chart on pages 5B 28 5B 31 or 5B 32 35 Pin MA 1 7 Metal Cased ECU Pin Circuits 12 and 27 24 Pin MSE 1 0 Plastic Cased ECU Pin Circuits 8 and 4 32 Pin MSE 1 1 Plastic Cased ECU Pin Circuits 8 and 4 a Repair or replace as required b Turn the idle speed screw back in to its original setting c Reconnect connector plugs start engine and retest system operation 5B 8 7 Remove the two mounting screws from the TPS Save the screws for reuse Remove and discard the faulty TPS Install the replacement TPS and secure with the original mounting screws a Reconnect both connector plugs b Perform the appropriate TPS Initialization Procedure integrating the new sensor to the ECU TPS Initialization Procedure For 35 Pin MA 1 7 Metal Cased ECU and 24 Pin MSE 1 0 Plastic Cased ECU only 1 Check that the basic engine all sensors fuel fuel pressure and battery are good and functionally within specifications Important 2 Remove
96. 26 Troubleshooting i Exe lo lero e shalom G70 cl ND Teer Teer Terre E tren o mT er eT rn rT 5B 26 FVM Oy SD NER T TIT E sess pai aca hae E o 5B 27 5B 33 lod e cuc T 5B 34 FOE CS E 5B 34 5B 43 TOU Pes i EIOW AU sistas ca petra irtupe verti E en do Ded Ubenli ku t isl inb b SUR UR NU AUN MUMM MED E 5B 43 5B 44 Flow CATS OS UCN esascuisaesi scutuap aue eticsepaunettgareais ra teaeates nnsienenemeasae aia aathesesternanlbnsnedeomtanncaaiaecnegetasie 5B 45 5B 46 Fe VC foo N Refer to Section 2 5B 1 Section 5B EFI Fuel System Description A WARNING Explosive Fuel can cause fires and severe burns Fuel system ALWAYS remains under HIGH PRESSURE A WARNING Explosive Fuel Gasoline is extremely flammable and its vapors can explode if ignited Store gasoline only in approved containers in well ventilated unoccupied buildings away from sparks or flames Do not fill the fuel tank while the engine is hot or running since spilled fuel could ignite if it comes in contact with hot parts or sparks from ignition Do not start the engine near spilled fuel Never use gasoline as a cleaning agent The EFI fuel system remains under high pressure even when the engine is stopped Before attempting to service any part of the fuel system the pressure must be relieved Pressure Tester part of
97. 7 325 Torque Conversions N m in Ib x 0 113 N m ft Ib x 1 356 in Ib N m x 8 85 ft Ib N m x 0 737 223 7 165 237 3 175 311 9 230 352 6 260 447 5 330 474 6 350 637 3 470 Section 2 Tools amp Aids Certain quality tools are designed to help you perform specific disassembly repair and reassembly procedures By using tools designed for the job you can properly service engines easier faster and safer In addition you ll increase your service capabilities and customer satisfaction by decreasing engine downtime Here is the list of tools and their source Separate Tool Suppliers Kohler Tools SE Tools Design Technology Inc Contact your source 415 Howard St 768 Burr Oak Drive of supply Lapeer MI 48446 Westmont IL 60559 Phone 810 664 2981 Phone 630 920 1300 Toll Free 800 664 2981 Fax 810 664 8181 Tools Balance Gear Timing Tool K amp M Series Kohler 25 455 06 5 To hold balance gears in timed position when assembling engine Formerly Y 357 Camshaft Endplay Plate For checking camshaft endplay ae eee Cylinder Leakdown Tester For checking combustion retention and if cylinder piston rings or valves are worn pore ene Electronic Fuel Injection EFI Diagnostic Software Kohler 25 761 23 5 Use with Laptop or Desktop PC EFI Service Kit For troubleshooting and setting up an EFI engine Kohler 24 761 01 5 Individual Components Available Design Technology Inc Pre
98. 7 2 kW 23 HP Giu RES MT 18 6 kW 25 HP OT T 19 4 kW 26 HP OTTO T E faves 20 1 kW 27 HP CEE 20 9 kW 28 HD CIT BO T 22 3 kW 30 HD Peak Torque CRU LE uo E OST Md EP 43 6 N m 32 2 ft Ib CEREO gia EOM M 44 3 N m 32 7 ft Ib CEZ CHO O CO AOR N r 49 1 N m 36 2 ft Ib iure us EOM NH Cr E 54 1 N m 37 9 ft Ib ipM Eur E 54 0 N m 39 5 ft Ib CET DEO UI quim S 55 4 N m 40 9 ft Ib iuis CH O9 0 2300RPM T C M 54 2 N m 40 0 ft Ib Giu EN idu P 57 3 N m 42 3 ft Ib A EET EV du ERN c MM 57 9 N m 42 7 ft Ib Giu INA OG duum n 64 4 N m 47 5 ft Ib Bore CH1IS CH620 CH20 CH640 C 122 C24 CC Joroisissa ina E AEE cac MOS RU 77 mm 3 03 in CEHIZZICEIGZU CH CA 07A C esha E EE RE E 80 mm 3 15 in CH25 CH26 CH735 CH730 CH740 CH745 CH750 esssseesesesssesseesssessresseessressressesssessse 83 mm 3 27 in Stroke i A E EAE EAE EEA AE AOE E E EA ETET 67 mm 2 64 in Sub 1 EEE E A E E EA TA T E A E TEA O T E 69 mm 2 7 in Displacement C HIS CHO20 C EIDO CHO40 CH2 624 C ogeesbeie uin usan ea orba baeo tU e r
99. 9 divides the regulator into two separate sections the fuel chamber and the pressure regulating chamber The pressure regulating spring presses against the valve holder part of the diaphragm pressing the valve against the valve seat The combination of atmospheric pressure and regulating spring tension equals the desired operating pressure Any time the fuel pressure against the bottom of the diaphragm exceeds the desired top pressure the valve opens relieving the excess pressure returning the excess fuel back to the tank Pressure Regulating Pressure Regulating Chamber Diaphragm LE ES E ee Ke pi EN Valve Seat Af TIT LSE SIA pL Jn Fuel Chamber Inlet Port Return Port to tank to fuel rail Figure 5B 29 Fuel Pressure Regulator Details Service Depending on the application the regulator may be located in the fuel tank along with the fuel pump or outside the tank just down line from the pump The regulator is a sealed non serviceable assembly If it is faulty it must be separated from the base holder assembly and replaced as follows 1 Shut engine off make sure engine is cool and disconnect the negative battery cable 2 Depressurize fuel system through test valve in fuel rail see fuel warning on page 5B 2 3 Access the regulator assembly as required and clean any dirt or foreign material away from the area 4 External Regulator Based upon the style of regulator used see Figure 5
100. Attach to chassis as close to ECU as possible Battery Attach to engine block near starter E Shield Attach to engine block near Coll 2 Wire from shield to ground Location to be as short as possible The Lambda o the engine via the exhaust sustem If a slip joint exhaust system is used a ding strap Fon the engine to the Muffler near the La ibda sensor iS required Fuel Pump Attach to chassis See Ground 30 87A Normal 1 2 4 9 6 8 9 9 Relay Contacts 30 87 pose phe Losed Not Used See Ground Note B Optional Rel ngs y General System Installation Notes The ignition switch must maintain constant voltage to circuits 17 31A and 41A as the key is swept fron run to start or start to run positions to prevent an ECU reset during starting a Ys The voltage on circuits 16 17 and 43 must remain within 10 2 volts of each other regardless of system current draw to prevent differences between actuator voltage circuits 40 44 and 45 and system sensed voltage circuit 17 If the ignition switch controls a powered circuit Cie Lights horn it is recommended that a relay be used to control the powered circuit as shown Each application wire harness conf iguration should be checked that the fuel pump fuse F2 fails open when the fuel pump is in a stalled or Locked condition A resistive spark plug with either a resistive spark plug wire on resistive spark
101. B 30 a Remove the two screws securing the mounting bracket to the regulator housing Remove the O Ring and pull the regulator out of the housing b Remove the snap ring and remove regulator from base holder Internal In Tank Regulator Remove the three screws securing the retaining ring and regulator in the base holder assembly Grasp and pull the regulator out of the base holder See Figure 5B 31 Section 5B EFI Fuel System Figure 5B 30 External Regulators and Base Holders Figure 5B 31 Internal Regulator and Base Holder 5 Always use new O Rings and hose clamps when installing a regulator A new replacement regulator will have new O Rings already installed Lubricate the O Rings external regulator with light grease or oil 6 a Install the new regulator by carefully pushing and rotating it slightly into the base or housing b External Regulators with Square Base Housing Only Install a new O Ring between the regulator and the mounting bracket Set the mounting bracket into position c Secure the regulator in base with the original retaining ring or screws Be careful not to dent or damage the body of the regulator as operating performance can be affected 7 Reassemble any parts removed in step 3 5B 21 Section 5B EFI Fuel System 8 Reconnect the negative battery cable 9 Recheck regulated system pressure at fuel rail test valve Fuel Filter EFI engines use a high volume
102. CU will relearn by its metal case with large 35 pin connector block the adapted values if the engine is operated for 10 15 and also as MA 1 7 See Figure 5B 1 The second minutes at varying speeds and loads after the oil and third styles have plastic cases but are smaller temperature exceeds 55 C 130 F in overall size These have either a 24 pin or 32 pin connector block and identified as MSE 1 0 or MSE To prevent engine over speed and possible failure a 1 1 respectively See Figures 5B 2 and 5B 3 Basic rev limiting feature is programmed into the ECU If function and operating control remains the same the maximum RPM limit 4125 RPM on MA 1 7 4500 between the three however due to differences in the RPM on MSE 1 0 amp MSE 1 1 is exceeded the ECU internal circuitry as well as the wiring harness none suppresses the injection signals cutting off the fuel of the ECU s are interchangeable Certain individual flow This process repeats itself in rapid succession service troubleshooting procedures also apply where limiting operation to the preset maximum applicable they are covered individually as 35 Pin MA 1 7 Metal Cased ECU 24 Pin MSE 1 0 Service Plastic Cased ECU or 32 Pin MSE 1 1 Plastic Never attempt to disassemble the ECU It is sealed to Cased ECU prevent damage to internal components Warranty is void if the case is opened or tampered with in any General way The ECU is the brain or central processing comp
103. Cased 1 1 ECU Sys ECU ECU Sys tem Only System tem o oo qwmw rj jr EBEN NN CR RR RC RR a re reseno NER RC cont on next page 9B 35 Section 5B EFI Fuel System OBD2 35 Pin 24 Pin 32 Pin P Code Ap MA 1 7 MSE 1 0 plicable to Connection or Failure Description Metal Plastic EIS 32 Pin MSE Cased Cased Cacad 1 1 ECU Sys ECU ECU Sys ECU tem Only System tem System EBENEN py ty fy py ty fy Lv py se fe quem pep m ERN CER m er EL momen ef umm EL TT EARMEN e Sram Lv M rv M wa oy M m oy NO oO C2 2 33 3 4 NO Temperature Sensor Circuit Shorted P0118 Temperature Sensor Circuit Open Circuit or Short to Battery Failure Completing Autolearn TPS Offset below minimum allowable limit Failure Completing Autolearn TPS N A offset above maximum allowable limit JI Co N JI JI C1 D D oO oO C2 OO oO NO NO NO A A C1 1 51 52 5B 36 Section 5B EFI Fuel System 32 Pin OBD2 35 Pin 24 Pin P Code Ap MA 1 7 MSE 1 0 plicable to Connection or Failure Description Metal Plastic Bao 32 Pin MSE Cased Cased Cased 1 1 ECU Sys ECU ECU tem Only System EM P0264 Injector 2 Short Circuit to Ground EM P0265 Injector 2 Short Circuit to Batt EM P1651 Diagnostic Lamp Open Circu E Lamp Short Circuit to a NNNM D oem rmn we wm E D orm nmm we we y ERNEEEL T NEN CE NER
104. Disassembly 2 Locate the three splitting tabs that are cast into the perimeter of the closure plate Insert the drive end of a 1 2 breaker bar between the top splitting tab and the crankcase Hold the handle horizontal and pull toward you to break the RTV seal If necessary pry at the bottom tabs also See Figures 9 67 and 9 68 Do not pry on the sealing surfaces as this could cause leaks Carefully pull closure plate from crankcase Figure 9 64 Removing Backing Plates and Stator Wire Bracket 2 Remove the two hex head screws and stator See Figure 9 65 Note the routing of the stator lead in the channel Remove Closure Plate Assembly 1 Remove the ten hex flange screws securing the closure plate to the crankcase See Figure 9 66 Figure 9 68 Breaking Seal on Top Splitting Tab Governor Gear Assembly The governor gear assembly is located inside the closure plate If service is required refer to the service procedures under Governor Gear Assembly in Section 10 Oil Pump Assembly The oil pump is mounted to the inside of the closure plate If service is required refer to the service procedures under Oil Pump Assembly in Section 10 Figure 9 66 Removing the Ten Closure Plate Fasteners 9 17 Section 9 Disassembly Remove Camshaft 1 Remove the camshaft and shim See Figure 9 69 Figure 9 71 Mark End Cap with Cylinder Number in i j Before Removal Figure 9 69 Removing Camshaft No
105. EFI Service Kit see Section 2 has an integral relief valve Connect the black tester hose to the test valve in the fuel rail Route the clear hose into a portable gasoline container Depress the button on the tester relief valve Initial Starting Priming Procedure Important The EFI fuel system must be purged of air primed prior to the initial start up and or any time the system has been disassembled or the fuel tank run dry 1 Locate the electronic control unit ECU for the EFI system Check the part number on the end If the Part No is 24 584 28 or higher the ECU has a built in priming feature a Turn the key switch to the on run position You will hear the fuel pump cycle on and off When the fuel pump stops cycling approximately one minute the system is primed start the engine 2 For plastic cased ECU s below 24 584 28 5 the system can be primed by manually cycling the fuel pump 5B 2 a Turn the key switch to the on run position The fuel pump will run for about three seconds and stop Turn the switch off and back on to restart the fuel pump Repeat this procedure until the fuel pump has cycled five times then start the engine 3 The system can also be primed similar to relieving pressure a Connect the pressure gauge as described above for relieving fuel pressure Depress and hold the release button and crank the engine until the air is purged and fuel is visible in the discharge tube If
106. Each is preset in correlation to a specific position of the throttle plate shaft or acts as a stop None of these attached components including the throttle plate or shaft requires disassembly or removal for any carburetor servicing All the components on the throttle shaft should be left intact If the settings of any one of these is inadvertently loosened or altered each must be checked reset or performance and operation will be affected Refer to the procedure included in the reassembly installation sequence to check or reset 5A 4 Impco Carburetor 1 Turn off fuel supply at tank 2 Remove the air cleaner breather hose fuel line vacuum hose choke and throttle linkages Remove the mounting hardware carburetor and gaskets from the engine Discard the gaskets 3 The carburetor venturi may be removed for inspection and appropriate cleaning a Remove the four screws securing the air cleaner adapter and gasket to the carburetor See Figure 5A 4 Figure 5A 4 b Important Mark a small line on the outer edge of the venturi for proper orientation and reinstallation later c Loosen the venturi retaining screw on the side of the carburetor body and lift out the venturi See Figure 5A 5 Figure 5A 5 Inspect the overall condition of the fuel enrichment hose attached to the carburetor It must be free of cracks deterioration and damage Disconnect the fuel enrichment hose from the carburetor fittings
107. Figure 11 87 Throttle Choke Control Bracket Detail Install Oil Sentry If So Equipped 1 Apply pipe sealant with Teflon Loctite No 59241 or equivalent to the threads of the Oil Sentry switch and install it into the breather cover See Figure 11 88 Torque to 4 5 N m 40 in Ib 2 Connect the wire lead green to the Oil Sentry terminal Install Control Panel If So Equipped 1 Install the panel to the blower housing 2 Connect the throttle control cable or shaft 3 Connect the choke control cable to the control bracket 4 Connect the Oil Sentry indicator light wires 11 26 Figure 11 88 Installing Oil Sentry Switch Install Valve Covers Three valve cover designs have been used The earliest type used a gasket and RTV sealant between the cover and sealing surface of the cylinder head The second type had a black O Ring installed in a groove on the underside of the cover and may have metal spacers in the bolt holes The newest design uses a yellow or brown O Ring with bolt hole spacers molded in place The tightening torque differs between gasket and O Ring style covers Kits are available for converting to the latest O Ring type covers Differences are pointed out in the following installation steps NOTE Do not scrape old RTV sealant if used off the sealing surface of the cylinder head as this could cause damage and result in leaks The use of gasket remover solvent paint remover is r
108. NC ROO Governed Idle Hole 390 3480 2 Clar 310133 4 Pope 35 310 3 Purple 28002000 2 Pupe 3750 3 Clear 5 Regulation others 10 11 24 Section 11 Reassembly 8 mm Governor Lever and Hole Position RPM Charts CH18 Engines 4 0000 3 Governor Lever 2 1 72 0O00 Intended Non Accelerator Accelerator Governor Shaft ide WOT RPM Pump Carburetor Pump Carburetor Configuration Spring Color Hole No Spring Color Hole No w S m um pit Standard Parent Material RPrRFNNN WKH WB eR NY RR RP rRNN WW W CH20 740 Engines Intended Non Accelerator Accelerator Governor Shaft igh WoT RPM Pump Sar oie Wo Pump Carburetor Configuration Spring Color Color Spring Color EI ir DD e 1 5 Standard Parent Material RPNRrRFNN WW We NH RR n rRNN WW W CH26 CH745 EFI Engines CH750 Engines Intended vonnguraien Highidie WOT SpringColor HoleNo Spring Color Hole No Standard Parent Material Pre rRF NN WW UC Section 11 Reassembly Description Bracket speed control Clamp cable some applications Kill Switch some applications Lever choke top position Lever throttle control middle Linkage choke control Lever throttle actuator bottom Screw M5x0 8x20 Washer wave Washer flat 3 Spring choke return Nut M5x0 8 lock en Fon c6 90 09 OU A QNA
109. SERVICE MANUAL KOHLER COMMAND CH18 CH26 CH620 CH750 HoRizoNTAL CRANKSHAFT E i S dt j Em EL LM KOHLER ENGINES Contents Section 1 Safety and General Information eere Leee e eeee e eese eene nnn Section 2 Tools amp AidS e ec eeeeeee neuen nnne n huh a nunun mua DR SERE SRRRRERORORRSRSR SR RsaROROR nnn Section 3 Troubleshooting 11 lee eiee ee Liee ee Leeeliienu eene nana nana aan n sanam a nana annm aaa Section 4 Air Cleaner and Air Intake System Section 5 Fuel System and Governor Section 5A LPG Fuel Systems Section 5B Electronic Fuel Injection EFI Fuel System Section 6 Lubrication System Section 7 Retractable Starter Section 8 Electrical System and Components Section 9 Disassembly 11 llle ieeeliiecliieeeiee nna n unen hash aa saa a a ausa sas a sas n n suas assa cra Section 10 Inspection and Reconditioning Sechon TT RGIS EMDI eia ee UEM LN EU ee EUM RESEe Dp MIFIPM ee Section 12 Clutch e ececeoeee rere unen nnnm huh usan RR RR RR RSRRRRERORERR RR SRRRRERRRORORORR nan Section 1 Safety and General Information Safety Precautions To ensure safe operation please read the following statements and understand their meaning Also refer to your equipment manufacturer s manual for other important safe
110. Se NNNNY CON NA r Ns NI P N PEZ Q i IM NA 1 8 27 NPT Plug Primary Diaphragm Assembly Primary Spring Expansion Plug Secondary Diaphragm Spring Primary Lever Assembly Fillister Head Screw Primary Pivot Pin Torx Head Screw Vac Lock Diaphragm Assembly Vac Lock Spring Figure 5A 20 NS WW B i IN DS Y A q NS NS y VS T INN um d p NO N So RL 4 N NS ens 4 E E 15 8 ze D 43 12 N iJ Ls 2777777 SE V all d LALA LL UL Lg gg l ZZ d RZ yf 9 Secondary Diaphragm Pan Head Screw Secondary Lever Spring Secondary Pivot Pin Secondary Lever Assembly Adjustment Screw Pan Head Screw Expansion Plug Diaphragm Gasket Split Lock Washer Section 5A LPG Fuel Systems Nikki Regulator Primary Chamber Nikki Regulator Secondary Chamber See Figure 5A 21 See Figure 5A 22 The primary chamber reduces the high pressure fuel The secondary chamber further reduces the fuel flow from the tank and vaporizer down to pressure from the 29 kPa 4 psi of the primary approximately 4 psi Fuel flowing from the vaporizer chamber to near 0 kPa 0 psi pressure to prevent enters the inlet of the regulator under approximately excessive fuel flow to the carburetor Fuel enters the 76 kPa 11 psi of pressure There it is delivered to the secondary chamber 13 through the clearance primary chamber 3 thro
111. Servicing Kit All Starters To remove and reinstall drive retaining rings and brushes SE Tools KLR 82411 Individual Component Available Starter Brush Holding Tool Solenoid Shift Tachometer Digital Inductive Design Technology Inc For checking operating speed RPM of an engine D IT 110 Vacuum Pressure Tester Kohler 25 761 22 8 Alternative to a water manometer T um abouti did SE Tools KLR 82413 For sizing valve guides after installation Valve Guide Service Kit Courage Aegis Command OHC SE Tools KLR 82415 For servicing worn value guides SE Tools KLR 82416 2 2 Section 2 Tools amp Aids Biss Dielectric Grease GE Novaguard G661 Kohler 25 357 11 S Electric Starter Drive Lubricant Inertia Drive Kohler 52 357 01 S Electric Starter Drive Lubricant Solenoid Shift Kohler 52 357 02 S RTV Silicone Sealant Kohler 25 597 07 S Loctite 5900 Heavy Body in 4 oz aerosol dispenser Only oxime based oil resistant RTV sealants such as those listed are approved for use Loctite Nos 5900 or 5910 are recommended for best sealing characteristics Loctite 5910 Loctite Ultra Black 598 Loctite Ultra Blue 587 Loctite Ultra Copper Spline Drive Lubricant Kohler 25 357 12 5 2 3 Section 2 Tools amp Aids Special Tools You Can Make 2 Remove the studs of a Posi Lock rod or grind off the aligning steps of a Command rod so the joint Flywheel Holding Tool surface is flat A flywheel holding too
112. Train Components 9 15 Section 9 Disassembly Figure 9 60 Removing Plastic Type Grass Screen 2 Remove the four hex flange screws and fan See Figure 9 61 Figure 9 61 Removing Fan Remove Flywheel 1 Use a flywheel strap wrench or holding tool see Section 2 to hold the flywheel and loosen the hex flange screw securing the flywheel to the crankshaft See Figure 9 62 NOTE Always use a flywheel strap wrench or holding tool to hold the flywheel when loosening or tightening the flywheel screw Do not use any type of bar or wedge to hold the flywheel Use of such tools could cause the flywheel to become cracked or damaged 9 16 il Figure 9 62 Removing Flywheel Fastener Using Strap Wrench 2 Remove the hex flange screw and washer 3 Use a puller to remove the flywheel from the crankshaft See Figure 9 63 NOTE Always use a flywheel puller to remove the flywheel from the crankshaft Do not strike the crankshaft or flywheel as these parts could become cracked or damaged Striking the puller or crankshaft can cause the crank gear to move affecting the crankshaft end play Figure 9 63 Removing Flywheel with a Puller 4 Remove the woodruff key from the crankshaft Remove Stator and Backing Plates 1 Remove the four hex flange screws securing the backing plates and stator wire bracket if equipped See Figure 9 64 Remove the backing plates and stator wire bracket Section 9
113. a problem in the Figure 5B 16 Style 1 Fuel Injector wiring or at the connector b If voltage is present the wiring to the connector is good Turn ignition switch off and proceed to test 5 to test the relay Terminal 86 Terminal 87 Feed ECU Controlled to Ignition Coils Ground Fuel Injectors and Fuel Pump Terminal Terminal 85 Ignition 487A a Switch Voltage Not Used l Figure 5B 17 Style 2 Fuel Injector Terminal 30 Permanent General Battery Voltage The fuel injectors mount into the intake manifold Figure 5B 15 Relay Terminal Details and the fuel rail attaches to them at the top end Replaceable O Rings on both ends of the injector 5 Connect an ohmmeter Rx1 scale between the prevent external fuel leakage and also insulate it 85 and 86 terminals in the relay There should from heat and vibration A special clip connects each be continuity See Figure 5B 15 injector to the fuel rail retaining it in place 5B 14 When the key switch is on and the relay is closed the fuel rail is pressurized and voltage is present at the injector At the proper instant the ECU completes the ground circuit energizing the injector The valve needle in the injector is opened electromagnetically and the pressure in the fuel rail forces fuel down through the inside The director plate at the tip of the injector see inset contains a series of calibrated openings which directs the fuel into the manifold in a cone sh
114. aced Additives and higher grades of fuel can be used as a preventative measure if clogging has been a problem Ignition System General A high voltage solid state battery ignition system is used with the EFI system The ECU controls the ignition output and timing through transistorized control of the primary current delivered to the coils Based on input from the speed sensor the ECU determines the correct firing point for the speed at which the engine is running At the proper instant it releases the flow of primary current to the coil The primary current induces high voltage in the coil secondary which is then delivered to the spark plug Each coil fires every revolution but every other spark is wasted Service Except for removing the spark plug lead by unscrewing it from the secondary tower see Figure 5B 22 no coil servicing is possible If a coil is determined to be faulty replacement is necessary An ohmmeter may be used to test the wiring and coil windings Figure 5B 22 Ignition Coil NOTE Do not ground the coils with the ignition on as they may overheat or spark Testing 1 Disconnect the main harness connector from ECU 5B 17 Section 5B EFI Fuel System 35 Pin MA 1 7 Metal Cased ECU Locate pins 1 and 19 in the 35 pin connector See page 5B 28 24 Pin MSE 1 0 Plastic Cased ECU Locate pins 22 and 23 in the 24 pin connector See page 5B 31 32 Pin MSE 1 1
115. ack lead attached to the AC lead reconnect it to the opposite side AC lead and repeat the test If the OK light green again comes on the part is good and may be used b If any other light is displayed in either of the tests the rectifier regulator is faulty and should not be used NOTE A flashing LOW light can also occur as a result of an inadequate ground lead connection Make certain connection location is clean and clamp is secure Figure 8 34 4 Amp Unregulated Rectifiers 1 Connect the tester ground lead with spring clamp to the body of rectifier being tested 2 Connect the ground lead of tester with spring clamp to the housing of rectifier regulator 3 Connect the red lead and one of the black leads from the tester to the pair of terminals on opposite end of adapter lead connections are not location specific 2 Connect the red tester lead to the B center terminal of the rectifier and the two black tester leads to the two AC outside terminals See Figure 8 36 4 Connect the remaining black lead from tester to one of the black AC outside leads from rectifier regulator See Figure 8 33 Figure 8 36 3 Plug the tester into the proper AC outlet power Figure 8 35 for tester being used Turn on the power switch The POWER light should be illuminated and 5 Plug the tester into the proper AC outlet power one of the four status lights may be on as well for tester being used Turn
116. adjust or service the carburetor 5 11 Section 5 Fuel System and Governor Low Idle Fuel Adjustments Low Idle Speed RPM Adjustment Screw Fuel Solenoid Figure 5 11 Keihin Two Barrel Carburetor Carburetor Adjustment Low Idle Speed RPM Adjustment 1 Low Idle Speed RPM Setting Place the throttle control into the idle or slow position Set the low idle speed to 1200 RPM 75 RPM by turning the low idle speed adjusting screw in or out Check the speed using a tachometer NOTE The actual low idle speed depends on the application Refer to the equipment manufacturer s recommendations The low idle speed for basic engines is 1200 RPM To ensure best results when setting the low idle fuel needle the low idle speed should be 1200 RPM 75 RPM Low Idle Fuel Adjustment NOTE Engines will have fixed low idle or limiter caps on the two idle fuel adjusting needles Step 3 can only be performed within the limits allowed by the cap Do not attempt to remove the limiter caps 1 Start the engine and run at half throttle for 5 to 10 minutes to warm up The engine must be warm before doing steps 2 3 and 4 2 Place the throttle control into the idle or slow position Adjust the low idle speed to 1200 RPM Follow the Adjusting the Low Idle Speed RPM procedure 3 Low Idle Fuel Needle s Setting Place the throttle into the idle or slow position 9 12 a Turn one of th
117. ag extus cet nea 624 cc 38 cu in C H22 CH670 CH23 CH680 074 CC osseenotetemsdort daHpui pni end reksi ns ieee s rin Ann E a RE E Eai 674 cc 41 cu in CH25 CH26 CH735 CH730 CH740 CH745 ss cmesuicnanesnamedinncnsmnssituabnabshcussaonesdumnsauceroubettagseanent 725 cc 44 cu in ep 755 cc 46 cu in Compression Ratio CHIS CH20 CEDO CTI640 CED2 CTIO70 CEI23 C680 is cscwnassncshudsmsebosusteaonanonawsncteaonens 8 5 1 Se Vy Balle CH SA0 eV UNG ay oeei rt rt e i R edes 9 0 1 OTT 90 IE AEN AE A A A AA A I A E 9 4 1 Dry Weight CHIS CHO20 C EDO HIOASO CIA 2 C1670 E3297 C E O9U ieestostestersutntsetoned encuestas 41 kg 90 Ib CRS CTO CEH enr 0C 0 CHAG os rare aust usta eN a AE A 43 kg 94 Ib A uU C A TE 48 kg 105 Ib Oil Capacity w filter approximate determined by oil MICE and oil cooler Sedan fictis o quA das dod iriennerien 1 6 1 8 L 1 7 1 9 U S qt Values are in Metric units Values in parentheses are English equivalents Lubricate threads with engine oil prior to assembly 1 8 Section 1 Safety and General Information General Specifications cont Angle of Operation Maximum At Full Oil Level All Directions 257 ZA Blower Housing and Sheet Metal MSTA tay qc olga OT U ea a E E ert ern rte 6 2 N m 55 in Ib into new holes 4 0 N m 35 in Ib into used holes
118. against the fuel inlet needle without depressing the center pin The correct float height setting is 17 mm 0 669 in 1 5 mm 0 059 in measured from the float bottom to the body of the carburetor See Figure 5 30 Replace the float if the height is different than the specified setting Do not attempt to adjust by bending float tab Figure 5 30 Checking Float Height NOTE Be sure to measure from the casting surface not the rubber gasket if still attached 5 17 Section 5 Fuel System and Governor 16 When the proper float height is obtained carefully reinstall the fuel bowl using new O Rings onto the carburetor Secure with the four original screws Torque the screws to 2 5 0 3 N m 23 2 6 in Ib See Figure 5 31 Figure 5 31 Installing Fuel Bowl Choke Repair Is Remove the carburetor from the engine Discard the old mounting gaskets for the air cleaner and carburetor Clean the areas around the choke shaft and the selt relieving choke mechanism thoroughly Remove and discard the plastic cap from the end of the choke lever shaft assembly Note the position of the spring legs and the choke plate for correct reassembly later See Figure 5 32 Remove the two screws attaching the choke plate to the choke shaft Pull the shaft out of the carburetor body and discard the removed parts Figure 5 32 Choke Details 5 18 Usea screw extractor easy out and remove the original choke
119. al contact cleaner to remove any old dielectric compound dark residue dirt or contamination Disconnect the spark plug leads from the spark plugs Remove one of the mounting screws from each of the ignition modules If the mounting screws are black remove them both and discard Replace them with part number M 561025 S Look in the mounting hole with a flashlight and use a small round wire brush to remove any loose rust from the laminations inside the mounting hole Refer to the chart on page 8 10 to identify which ignition module s you have If they are the smaller style check the vendor part number on the face All modules with vendor part numbers MA 2 MA 2A or MA 2B Kohler Part No 24 584 03 should be replaced with 24 584 11 or 24 584 15 5 For small modules with vendor numbers MA 2C or MA 2D Kohler Part No 24 584 11 or the larger style modules 24 584 15 5 and 24 584 36 5 use a digital ohmmeter to check the resistance values and compare them to the table following When testing resistance to the laminations touch the probe to the laminations inside the screw hole as some laminations have a rust preventative coating on the surface which could alter the resistance reading a If all of the resistance values are within the ranges specified in the table go to step 5 b If any of the resistance values are not within the ranges specified in the table that module is faulty and must be replaced NOTE The resist
120. an cause damage similar to detonation Preignition damage is often more severe than When cylinder temperatures get too high lacquer and detonation damage Preignition is caused by a hot varnish collect on pistons causing rings to stick which spot in the combustion chamber from sources such as results in rapid wear A worn ring usually takes on a glowing carbon deposits blocked cooling fins an shiny or bright appearance improperly seated valve or wrong spark plug s Scratches on rings and pistons are caused by abrasive See Figure 10 8 for some common types of piston and material such as carbon dirt or pieces of hard metal ring damage n nal wi a E rri mg mre m wh Pu i qu nda T n ou AEN i AMET m t i i 3 1 i 1 lul AN t ly i i E g LAT Wi E ZUM if HG I T IE Lm BN IL d N Hl ne e 1 k l i MES ud mE Hg Y H irm VM II t It Eii jj Hil T vni M 7m Uo Alc AA d T oM i Overheated or Deteriorated Oil Scored Piston and Rings Figure 10 8 Common Types of Piston Damage 10 9 Section 10 Inspection and Reconditioning Replacement pistons are available in STD bore size and in 0 25 mm 0 010 in and 0 50 mm 0 020 in oversize Replacement pistons include new piston ring sets and new piston pins Replacement ring sets are also available separately for STD 0 25 mm 0 010 in and 0 50 mm 0 020 in oversize pistons Always use new piston
121. an injector and listen for a change in idle performance only running on one cylinder or a change in injector noise or vibration If an injector is not operating it can indicate either a bad injector or a wiring electrical connection problem Check as follows NOTE Do not apply voltage to the fuel injector s Excessive voltage will burn out the injector s Do not ground the injector s with the ignition on Injector s will open turn on if relay is energized 1 Disconnect the electrical connector from both injectors Plug the 12 volt Noid Light part of EFI Service Kit see Section 2 in one connector 5B 15 Section 5B EFI Fuel System Figure 5B 20 Volt Noid Light 2 Make sure all safety switch requirements are met Crank the engine and check for flashing of noid light Repeat test at other connector a 5B 16 If flashing occurs use an ohmmeter Rx1 scale and check the resistance of each injector across the two terminals Proper resistance is 12 20 If injector resistance is correct check whether the connector and injector terminals are making a good connection If the resistance is not correct replace the injector following steps 1 8 and 13 16 below If no flashing occurs reattach connectors to both injectors Disconnect the main harness connector from the ECU and the connector from the relay Set the ohmmeter to the Rx1 scale and check the injector circuit resistance as follows 35 Pin
122. ance values apply only to modules that have been on a running engine New service modules may have higher resistance until they have been run Ignition Module Resistance Table 24 584 03 or 24 584 11 1 11 46 in H 24 584 03 24 584 11 1 11 16 in H Test Use Digital Ohmmeter 945 to 1175 ohms 149 to 166 ohms 3 50 to 7000 ohms 24 584 15 S or 24 584 36 S 2 1 16 in H 24 584 15 S 2 1 16 in H 890 to 1175 ohms 119 to 136 ohms 8000 to 40 000 ohms 5600 to 9000 ohms 5 Check and or adjust the ignition module air gap s An air gap of 0 28 0 33 mm 0 011 0 013 in must be maintained under all three legs of the ignition module s Checking adjusting should be performed with the parts at room temperature a If the module was not loosened or replaced check that the specified air gap is present under all three legs If the gap is correct reinstall the second mounting screw removed earlier and recheck gap after tightening b If the gap is incorrect or the module was loosened or replaced adjust the gap as follows 1 Turn the flywheel magnet away from the module position 2 Attach the module to the mounting legs pull it away from the flywheel and snug the screws to hold it temporarily 3 Rotate the flywheel so the magnet is centered under the module 4 Position a 0 30 mm 0 012 in feeler gauge between the magnet and all three legs of the module The igniti
123. ankcase See Figure 11 36 Make sure the head is flat on the gasket and dowel pins 5 Lightly lubricate the exposed upper threads of the studs with engine oil Install a flat washer and hex nut onto each of the mounting studs Torque the hex nuts in two stages first to 16 9 N m 150 in Ib finally to 33 9 N m 300 in Ib following the sequence in Figure 11 42 Mounting Nuts Stud Design Install Push Rods and Rocker Arms Early models used hollow push rods with special rocker arms They are not interchangeable with the later current style solid push rods and associated rocker arms Do not mix these A replacement kit is available with solid components Section 11 Reassembly NOTE Push rods should always be installed in the same position as before disassembly 1 Note the mark or tag identifying the push rod as either intake or exhaust and cylinder 1 or 2 Dip the ends of the push rods in engine oil and install making sure that each push rod ball seats in its hydraulic lifter socket See Figure 11 45 Figure 11 45 Install Push Rods in Their Original Position 2 Apply grease to the contact surfaces of the rocker arms and rocker arm pivots Install the rocker arms and rocker arm pivots on one cylinder head and start the two hex flange screws See Figure 11 46 m i ee 4 x Figure 11 46 Torquing Rocker Arm Screws 3 Torque the hex flange screws to 11 3 N m 100 in Ib Repeat for the ot
124. aped spray pattern P Kg n DE a y eam o pee aimee oe Cy is ia p 9 Multi Orifice Director Plate with Calibrated Opening 5 Armature 6 Valve body 7 Valve needle 1 Filter strainer in fuel supply 2 Electrical connection 3 Solenoid winding 4 Valve housing Figure 5B 18 Fuel Injector Details The injector is opened and closed once for each crankshaft revolution however only one half the total amount of fuel needed for one firing is injected during each opening The amount of fuel injected is controlled by the ECU and determined by the length of time the valve needle is held open also referred to as the injection duration or pulse width It may vary in length from 1 5 8 milliseconds depending on the speed and load requirements of the engine Section 5B EFI Fuel System Service Injector problems typically fall into three general categories electrical dirty clogged or leakage An electrical problem usually causes one or both of the injectors to stop functioning Several methods may be used to check if the injectors are operating 1 With the engine running at idle feel for operational vibration indicating that they are opening and closing 2 When temperatures prohibit touching listen for a buzzing or clicking sound with a screwdriver or mechanic s stethoscope see Figure 5B 19 Figure 5B 19 Checking Injectors 3 Disconnect the electrical connector from
125. backing plate from the end cap See Figure 8 55 Figure 8 52 Removing Thru Bolts 5 Remove the commutator end plate assembly Figure 8 55 containing the brush holder brushes springs and locking caps Remove the thrust washer from 8 Take out the drive lever and pull the armature inside the commutator end See Figure 8 53 out of the drive end cap See Figure 8 56 9 Remove the thrust washer from the armature shaft See Figure 8 56 Figure 8 53 Removing Commutator End Plate Assembly 6 Remove the frame from the armature and drive end cap See Figure 8 54 Figure 8 56 Armature and Lever Removed Figure 8 54 Starter Frame Removed 8 37 Section 8 Electrical System and Components 10 Push the stop collar down to expose the retaining ring See Figure 8 57 Figure 8 57 Retaining Ring Detail 11 Remove the retainer from the armature shaft Save the stop collar NOTE Do not reuse the old retainer Armature Washer Figure 8 58 Removing Retaining Ring 12 Remove the drive pinion assembly from the armature 13 Clean the parts as required NOTE Do not soak the armature or use solvent when cleaning Wipe clean using a soft cloth or use compressed air Plunger Spring Lever Plate Plug Solenoid Frame amp Field Brush Holder Nut CE Frame Screw Bolt Figure 8 59 Delco Remy Starter 8 38 Inspection Drive Pinion Check and inspect the followi
126. battery drops below 9 volts while cranking the battery is too small 5 F to 0 F 21 C to 18 C discharged or faulty If the battery charge is insufficient to turn over the engine recharge the battery ph DC Voltmeter Battery Maintenance Regular maintenance is necessary to prolong battery life A WARNING Explosive Gas Batteries produce explosive hydrogen gas while being charged To prevent a fire or explosion charge batteries only in well ventilated areas Keep sources of ignition away from the battery at all times Keep batteries out of the reach of children Remove all jewelry when servicing batteries Before disconnecting the negative ground cable make sure all switches are OFF If ON a spark will occur at the ground cable terminal which could cause an explosion if hydrogen gas or gasoline vapors are present Figure 8 2 Battery Voltage Test 1 Regularly check the level of electrolyte Add distilled water as necessary to maintain the recommended level NOTE Do not overfill the battery Poor performance or early failure due to loss of electrolyte will result 8 3 Section 8 Electrical System and Components Electronic Ignition Systems There are three different types of ignition systems used on these engines All systems use an ignition module which energizes the spark plug The difference in the system is in the way the ignition timing is triggered The Fixed Ignition System utilizes a Capaci
127. bed following Float Circuit The fuel level in the bowl is maintained by the float and fuel inlet needle The buoyant force of the float stops fuel flow when the engine is at rest When fuel is being consumed the float will drop and fuel pressure will push the inlet needle away from the seat allowing more fuel to enter the bowl When demand ceases the buoyant force of the float will again overcome the fuel pressure rising to the predetermined setting and stop the flow Slow amp Mid Range Circuit At low speeds the engine operates only on the slow circuit As a metered amount of air is drawn through the slow air bleed jets fuel is drawn through the two main jets and further metered through the slow jets Air and fuel are mixed in the body of the slow jet and exit to the transfer port From the transfer port the air fuel mixture is delivered to the idle progression chamber From the idle progression chamber the air fuel mixture is metered through the idle port passages At low idle when the vacuum signal is weak the air fuel mixture is controlled by the setting of the idle fuel adjusting screws This mixture is then mixed with the main body of air and delivered to the engine As the throttle plate opening increases greater amounts of air fuel mixture are drawn in through the fixed and metered idle progression holes As the throttle plate opens further the vacuum signal becomes great enough so the main circuit begins to work S
128. ble to recognize or process signals from its memory Expected Engine Response Engine will not run Possible Causes 1 ECU internal memory problem a Diagnosable only through the elimination of all other system component faults Code 24 Will not blink out Source Engine Speed Sensor Explanation No tooth signal from speed sensor MIL light will not go out when cranking Expected Engine Response None engine will not start or run as ECU is unable to estimate speed Possible Causes 1 Engine Speed Sensor Related a Sensor connector or wiring b Sensor loose or air gap incorrect 2 Speed Sensor Wheel Related a Damaged teeth b Gap section not registering 3 Engine Wiring Harness Related a Pin circuit wiring or connectors Pin s 3 and or 21 for 35 Pin MA 1 7 Metal Cased ECU Pin s 9 and or 10 for 24 Pin MSE 1 0 Plastic Cased ECU Pin s 9 and or 10 for 32 Pin MSE 1 1 Plastic Cased ECU 4 ECU Harness Related a ECU to harness connection problem Section 5B EFI Fuel System Code 31 Source Fuel Mixture or Oxygen Sensor Explanation System too lean Oxygen sensor not sending expected voltage to ECU Expected Engine Response System operates under open loop control only Until fault is detected and registered by ECU engine will run rich if oxygen sensor is shorted to ground or lean if it is shorted to battery voltage After fault is detected performance can vary depend
129. buretor Detail 5 Hold the carburetor upper body so that the float assembly hangs vertically and rests lightly against the fuel inlet needle The fuel inlet needle should be fully seated but the needle tip should not be depressed See Figure 5 9 NOTE The fuel inlet needle tip is spring loaded Make sure the float assembly rests against the fuel inlet needle without depressing the tip 6 The correct float height adjustment is 22 mm 0 86 in measured from the float bottom to the air horn casting Adjust the float height by carefully bending the tab NOTE Be sure to measure from the casting surface not the rubber gasket surface 7 If proper float height adjustment cannot be achieved check to see if the fuel inlet needle is dirty obstructed or worn Remove the brass screw and float assembly to remove the fuel inlet needle 5 8 Figure 5 9 Carburetor Float Adjustment 8 10 Once the proper float height is obtained carefully lower the carburetor air horn assembly onto the carburetor body connecting the choke linkage Install the four screws Torque the screws to 1 7 N m 15 in Ib See Figure 5 8 Connect the fuel line Install the breather hose and air cleaner assembly following the steps in Section 11 Reassembly Disassembly Disassemble the carburetor using the following steps See Figure 5 10 Lh Remove the air cleaner breather hose and carburetor Refer to Section 9 Disassemb
130. camshaft for wear or damage See Section 1 for minimum lift specifications Inspect the cam gear for badly worn chipped or missing teeth Replacement of the camshaft will be necessary if any of these conditions exist Crankshaft Inspection and Service Inspect the gear teeth of the crankshaft If the teeth are badly worn chipped or some are missing replacement of the crankshaft will be necessary 10 1 Section 10 Inspection and Reconditioning Inspect the crankshaft bearing surfaces for scoring grooving etc Some engines have bearing inserts in the crankshaft bore of the closure plate and or crankcase Do not replace bearings unless they show signs of damage or are out of running clearance specifications If the crankshaft turns easily and noiselessly and there is no evidence of scoring grooving etc on the races or bearing surfaces the bearings can be reused Inspect the crankshaft keyways If they are worn or chipped replacement of the crankshaft will be necessary Inspect the crankpin for score marks or metallic pickup Slight score marks can be cleaned with crocus cloth soaked in oil If the wear limits as stated in Specifications and Tolerances are exceeded it will be necessary to either replace the crankshaft or regrind the crankpin to 0 25 mm 0 010 in undersize If reground a 0 25 mm 0 010 in undersize connecting rod big end must then be used to achieve proper running clearance Measure the crank
131. cessary all four brushes should be replaced 1 Remove the brushes from the brush holder and remove the brush holder from the frame 2 Cut the brush lead wire at the edge of the post with a pair of nippers 3 File off any burrs on the post Figure 8 48 Completed Delco Remy Starter 4 The replacement brushes have a solid portion on Starter Disassembly A e a o a DOS 1 Remove the hex nut and disconnect the positive brush lead ket f the solenoid terminal 5 Solder the crimped portion to the post DEE Ea aee a aA 2 Remove the three screws securing the solenoid to 6 Replace the brush holder in the frame and place the starter See Figure 8 49 the brushes in the brush holder Reinstall the springs 8 35 Section 8 Electrical System and Components Phillips Head Screws Figure 8 49 Removing Solenoid Screws 3 If the solenoid was mounted with Phillips head screws separate the solenoid and plunger spring from the drive end cap If the solenoid was mounted with external Torx head screws the plunger is part of the solenoid unhook the plunger pin from the drive lever Remove the gasket from the recess in the housing See Figures 8 50 and 8 51 NOTE Test procedure for checking starter solenoid on pages 8 44 and 8 45 Figure 8 51 Removing Plunger 4 Remove the two thru larger bolts See Figure 8 52 8 36 Section 8 Electrical System and Components 7 Remove the drive lever pivot bushing and
132. choke Choke plate and shaft assembly is spring loaded Check to make sure plate moves freely and is not binding and affecting idle fuel delivery 4 Place the throttle control into the idle or slow position Turn the low idle speed adjusting screw in or out to obtain a low idle speed of 1200 RPM 75 RPM Check the speed using a tachometer NOTE The actual low idle speed depends on the application Refer to the equipment manufacturer s recommendations The low idle speed for basic engines is 1200 RPM To ensure best results when setting the low idle fuel needle the low idle speed should be 1200 RPM 75 RPM 5 Turn the low idle fuel adjusting needle in slowly until engine speed decreases and then back out approximately 3 4 turn to obtain the best low speed performance 6 Recheck the idle speed using a tachometer and readjust the speed as necessary Models with Governed Idle System An optional governed idle control system is supplied on some engines The purpose of this system is to maintain a desired idle speed regardless of ambient conditions temperature parasitic load etc that may change Engines with this feature contain a small secondary spring connected between the governor lever and the lower adjustment tab of the main bracket See Figure 5 6 The system requires an additional procedure for setting the idle speed If speed adjustments are required proceed as follows 1 Make any necessary speed or contr
133. ck 4 Remove dipstick and check oil level The level should be between the F and L marks If low add oil of the proper type up to the F mark Reinstall oil fill cap and dipstick Operating Range Figure 6 3 Oil Level Marks on Dipstick NOTE To prevent extensive engine wear or damage always maintain the proper oil level in the crankcase Never operate the engine with the oil level below the L mark or above the F mark on the dipstick Changing Oil and Oil Filter Changing Oil Change the oil after every 100 hours of operation more frequently under severe conditions Refill with service class SG SH SJ or higher oil as specified in the Viscosity Grades table on page 6 1 Change the oil while the engine is still warm The oil will flow more freely and carry away more impurities Make sure the engine is level when filling or checking oil Change the oil as follows 1 Clean the areas around one of the oil drain plugs oil fill cap and dipstick 2 Remove one of the oil drain plugs A drain plug is located on either side of the crankcase one is adjacent to and below the oil filter the other is below the starter See Figure 6 4 Figure 6 4 Location of Oil Drains 6 2 3 Allow all the oil to drain and then reinstall the drain plug Torque to 13 6 N m 10 ft Ib 4 Remove the oil fill cap and fill the engine with the proper oil to the F mark on the dipstick Always che
134. ck the oil level with the dipstick before adding more oil Figure 6 5 Removing Oil Fill Cap 5 Reinstall the oil fill cap Changing Oil Filter Replace the oil filter at least every other oil change every 200 hours of operation Always use a genuine Kohler oil filter Change the filter as follows See Figure 6 6 Cil Filter t pcm Oil Cooler Oil Drain Plug Figure 6 6 Oil Drain Plug and Oil Filter Engine With Oil Cooler 10 Section 6 Lubrication System Clean the areas around the drain plug oil filter oil fill cap and dipstick Remove one of the oil drain plugs A drain plug is located on either side of the crankcase one is adjacent to and below the oil filter the other is below the starter Allow all oil to drain and then reinstall the drain plug Torque to 13 6 N m 10 ft Ib Remove the old filter and wipe off the filter adapter with a clean cloth Place a new replacement filter in a shallow pan with the open end up Pour new oil of the proper type in through the threaded center hole Stop pouring when the oil reaches the bottom of the threads Allow a minute or two for the oil to be absorbed by the filter material Apply a thin film of clean oil to the rubber gasket 6 on the new filter Install the new oil filter to the filter adapter or oil cooler Refer to instructions on the oil filter for proper installation Remove the oil fill cap and fill the engine with the prope
135. commendations for Standard Applications E Tightening Torque N m in Ib or 10 Property Class Noncritical Fasteners Into Aluminum Size M4 44 2 0 86 4 0 35 M6 3 38 A 16 5 146 6 8 60 M8 10 5 93 i 40 7 360 17 0 150 11 5 0 18 9 7 12 M5 2 5 22 43 Tightening Torque N m ft Ib or 10 Property Class Noncritical Into Aluminum M10 21 7 16 27 1 20 47 5 35 66 4 49 81 4 60 33 9 25 M12 36 6 27 47 5 35 82 7 61 116 6 86 139 7 103 61 0 45 M14 58 3 43 76 4 55 131 5 97 184 4 136 219 7 162 94 9 70 Section 1 Safety and General Information English Fastener Torque Recommendations for Standard Applications Tightening Torque N m in Ib or 20 Bolts Screws Nuts and Fasteners Assembled Into Cast Iron or Steel Grade 2 or 5 Fasteners Into Aluminum OO 2 3 20 2 8 o5 2 3 20 3 6 32 4 5 40 3 6 32 4 5 40 7 9 70 13 0 115 18 7 165 9 6 85 15 8 140 22 6 200 17 0 150 28 3 250 39 6 350 18 7 165 30 5 270 29 4 260 33 9 300 Tightening Torque N m ft Ib or 20 40 7 30 47 5 35 67 8 50 54 2 40 81 4 60 47 5 35 74 6 55 108 5 80 61 0 45 101 7 75 142 4 105 67 8 50 108 5 80 155 9 115 94 9 70 101 7 75 135 6 100 149 2 110 189 8 140 199 3 150 271 2 200 142 4 105 169 5 125 223 7 165 244 1 180 311 9 230 332 2 245 440
136. conditioning The final cleaning operation should always be a thorough scrubbing with a brush and hot soapy water Use a strong detergent that is capable of breaking down the machining oil while maintaining a good level of suds If the suds break down during cleaning discard the dirty water and start again with more hot water and detergent Following the scrubbing rinse the cylinder with very hot clear water dry it completely and apply a light coating of engine oil to prevent rusting Measuring Piston to Bore Clearance Before installing the piston into the cylinder bore it is necessary that the clearance be accurately checked This step is often overlooked and if the clearances are not within specifications engine failure will usually result NOTE Do not use a feeler gauge to measure piston to bore clearance it will yield inaccurate measurements Always use a micrometer Use the following procedure to accurately measure the piston to bore clearance 1 Usea micrometer and measure the diameter of the piston 6 mm 0 24 in above the bottom of the piston skirt and perpendicular to the piston pin See Figure 10 4 6 mm 0 24 in 4 Measure 6 mm above the Bottom of Piston Skirt at Right Angles to Piston Pin Figure 10 4 Measuring Piston Diameter 2 Useaninside micrometer telescoping gauge or bore gauge and measure the cylinder bore Take the measurement approximately 63 5 mm 2 5 in below the top of the
137. connect the oxygen sensor lead With the lead connected probe or connect the sensor connection with the red VOA meter lead Attach the black VOA meter lead to a known good ground location Start and run the engine at 3 4 throttle and note the voltage output The reading should cycle between 0 2 v 1 0 v which indicates the oxygen sensor is functioning normally and also the fuel delivery controlled by the ECU is within prescribed parameters If the voltage readings show a steady decline bump the governor lever to make the engine accelerate very quickly and check the reading again If voltage momentarily increases and then again declines without cycling engine may be running lean due to incorrect TPS initialization Shut off the engine perform TPS initialization and then repeat the test If TPS initialization cannot be achieved perform step c c Replace the oxygen sensor page 5B 13 Run the engine long enough to bring the new sensor up to temperature and repeat the output test from step 1 The cycling voltage from 0 2 to 1 0 volt should be indicated 2 Move the black voltmeter lead to the engine ground location and repeat the output test The same voltage 0 2 v 1 0 v should be indicated a If the same voltage reading exists go on to otep 3 b If the voltage output is no longer correct a bad ground path exists between the sensor and the engine ground Touch the black lead at various points backtracking from the eng
138. connected Test 1 Isolate and Verify the Trouble is Within the Engine Ignition System 1 Locate the connectors where the wiring harnesses from the engine and equipment are joined Separate the connectors and remove the white kill lead from the engine connector Rejoin the connectors and position or insulate the kill lead terminal so it cannot touch ground 8 16 Try to start the engine to verify whether the reported problem is still present NOTE If the engine starts or runs during any of the testing you may need to ground the kill lead to shut it down Because you have interrupted the kill circuit it may not stop using the switch a If the problem goes away the electrical system on the equipment is suspect Check the key switch wires connections safety interlocks etc b If the problem persists the condition is associated with the ignition or electrical system of the engine Leave the kill lead isolated until all testing is completed c Identify the white kill lead of the engine wiring harness connector Establish a connection to a known good ground location The engine should kill completely If not or only one cylinder is affected go to Test 4 but also check the white kill lead connection for the affected DSAI module Test 2 Test for Spark 1 With the engine stopped disconnect one spark plug lead Connect the spark plug lead to post terminal of spark tester Kohler Part No 25 455 01 5 and attach t
139. crew Position and install the new choke plate to the flat side of the choke shaft Start the two screws Close the choke and check the plate alignment within the carburetor throat then tighten the screws securely Do not overtighten See Figure 5 36 Section 5 Fuel System and Governor Figure 5 36 Installing Choke Plate 12 Check for proper operation and free movement of the parts Install the new cap Always use new gaskets when servicing or reinstalling carburetors Repair kits are available which include new gaskets and other components Service repair kits available for Keihin BK two barrel carburetors and affiliated components are Carburetor Overhaul Kit Float Kit Fuel Solenoid Kit Choke Repair Kit Bowl Kit High Altitude Kit 1219 2434 m 4 000 8 000 ft 5 19 Section 5 Fuel System and Governor Figure 5 37 Keihin BK Two Barrel Carburetor Exploded View 5 20 Ee LOU ES sd s Carburetor Body Subassembly Idle Speed Screw Idle Speed Spring Screw Ground Lead Retaining Washer Slow Jet RH Side Slow Jet LH Side O Ring Slow Jet 2 Fuel Bowl O Ring Fuel Bowl Upper O Ring Fuel Bowl Lower Drain Screw Bowl Screw 4 Fuel Solenoid Sealing Washer Float Pin Screw Float Clip Float Valve Inlet Needle Main Nozzle Right Side Main Nozzle Left Side Main Jet Right Side Main Jet Left Side Choke Dust Cap
140. crews or hex flange nuts and washers on studs Do not interchange or mix components as the cylinder heads may have different machining unique to each fastening method 1 Remove the four hex flange screws or hex nuts and washers securing each cylinder head See Figure 9 51 Discard the screws or nuts and washers once removed Do not reuse Studs if present should only be removed if damaged or if cylinder reconditioning is necessary Once removed they must be replaced Section 9 Disassembly Hex Flange Screw Hex Flange Nut and Washer Figure 9 51 Removing Cylinder Head Fasteners 2 Mark the position of the push rods as either intake or exhaust and cylinder 1 or 2 Push rods should always be reinstalled in the same positions 3 Carefully remove the push rods cylinder heads and head gaskets See Figure 9 52 9 13 Section 9 Disassembly Stud and Hex Flange Nut Style Mounting Figure 9 52 Removing Cylinder Head Assembly 4 Remove the lifters from the lifter bores Use a Hydraulic Lifter Tool Do not use a magnet to remove lifters Mark the lifters by location as either intake or exhaust and cylinder 1 or 2 Hydraulic lifters should always be reinstalled in the same position See Figures 9 53 and 9 54 NOTE The exhaust lifters are located on the output shaft side of the engine while the intake lifters are located on the fan side of the engine The cylinder head number is embossed on the outside of each
141. ctice to drain oil at a location away from the workbench Be sure to allow ample time for complete drainage Cleaning the Engine After inspecting the external condition of the engine clean the engine thoroughly before disassembling it Also clean individual components as the engine is disassembled Only clean parts can be accurately inspected and gauged for wear or damage There are many commercially available cleaners that will quickly remove grease oil and grime from engine parts When such a cleaner is used follow the manufacturer s instructions and safety precautions carefully Make sure all traces of the cleaner are removed before the engine is reassembled and placed into operation Even small amounts of these cleaners can quickly break down the lubricating properties of engine oil Basic Engine Tests Crankcase Vacuum Test A partial vacuum should be present in the crankcase when the engine is operating Pressure in the crankcase normally caused by a clogged or improperly assembled breather can cause oil to be forced out at oil seals gaskets or other available spots Crankcase vacuum is best measured with either a water manometer or a vacuum gauge see Section 2 Complete instructions are provided in the kits Section 3 Troubleshooting To test the crankcase vacuum with the manometer i Insert the stopper hose into the oil fill hole Leave the other tube of manometer open to atmosphere Make sure the shut of
142. cylinder head See Figure 9 55 9 14 Figure 9 55 Match Marks on Cylinder Barrel and Heads Section 9 Disassembly Disassemble Cylinder Heads 3 Once the valve spring is compressed remove the 1 Remove the two hex flange screws rocker arm following items See Figures 9 58 and 9 59 pivots and rocker arms from the cylinder head See Figure 9 56 Valve spring keepers Valve spring retainers Valve springs Valve spring caps Intake and exhaust valves mark position Valve stem seals intake valve only Valve Seal Figure 9 56 Removing Rocker Arms 2 Compress the valve springs using a valve spring compressor See Figure 9 57 Figure 9 59 Intake Valve Seal Location NOTE These engines use valve stem seals on the intake valves Use a new seal whenever valve is removed or if the seal is deteriorated in any way Never reuse an old seal 4 Repeat the above procedure for the other cylinder head Do not interchange parts from one cylinder head to the other Remove Grass Screen and Fan 1 Small metal retainers are typically attached on three of the seven mounting posts for positive retention of the plastic grass screen Use a hook end tool next to the post and pull outward to separate each of the small metal retainers Then unsnap the fan from the remaining mounting posts See Figure 9 60 Figure 9 57 Removing Valves with Valve Spring Compressor Keepers Retainer Figure 9 58 Valve
143. d circuit can affect the output signal and trigger misleading fault codes Keep that in mind when doing any troubleshooting associated with the oxygen sensor The oxygen sensor can also be contaminated by leaded fuel certain RTV and or other silicone compounds carburetor cleaners etc Use only those products indicated as O Sensor Safe Oxygen Sensor Figure 5B 11 Oxygen Sensor Service Like the other sensors already discussed the oxygen sensor is a non serviceable component Complete replacement is required if it is faulty The sensor and wiring harness can be checked as follows General The oxygen sensor functions like a small battery generating a voltage signal to the ECU based upon the difference in oxygen content between the exhaust gas and the ambient air NOTE All tests should be conducted with a good quality high impedance digital VOA meter for accurate results 5B 11 Section 5B EFI Fuel System 1 Oxygen sensor must be hot minimum of 400 C voltage change at each location If the correct 725 F Run engine for about 5 minutes With the engine running disconnect the oxygen sensor lead from the wiring harness Set VOA meter for DC volts and connect the red lead to the disconnected sensor lead and the black lead to the sensor shell Check for a voltage reading between 0 2 v 1 0 v a If voltage is in the specified range go to Step 2 b Ifthe voltage is not in the specified range re
144. d be replaced Figure 10 13 Removing Governor Gear 2 Remove the locking tab thrust washer located under the governor gear assembly 3 Carefully inspect the governor gear shaft and replace it only if it is damaged After removing the damaged shaft press or lightly tap the replacement shaft into the closure plate to the depth shown in Figure 10 14 pear Shaft 34 0 mm 1 3386 in 33 5 mm 1 3189 in Figure 10 15 Oil Pump Oil Pickup and Relief Valve Original Style Figure 10 14 Governor Shaft Press Depth 10 12 Section 10 Inspection and Reconditioning 3 Install the rotor 4 Install the oil pump body to the closure plate and secure with the two hex flange screws Torque the hex flange screws as follows a Install fastener into location No 1 and lightly tighten to position pump b Install fastener into location No 2 and fully torque to the recommended value c Torque fastener in location No 1 to the recommended value Figure 10 16 Oil Pump Oil Pickup and One Piece Relief Valve Later Style Inspection Inspect the oil pump housing gear and rotors for nicks burrs wear or any visible damage If any parts are worn or damaged replace the oil pump Inspect the oil pressure relief valve piston It should be free of nicks or burrs Check the spring for wear or distortion The free length of the spring should be approximately 47 4 mm 1 8 in Replace the spring if it is disto
145. d to the short yellow or pink module lead See Figure 8 13 Leave the red and green leads connected Repeat step 2 Figure 8 13 Ihe tester is powered by a 9 volt battery Most SAMs are designed to operate down to a minimum of 7 25 volts If the tester battery drops below that level incorrect test readings will result The tester battery should be checked periodically by connecting a DC voltmeter between the red and green lead wires with the tester connected to a SAM Press and hold the test button for a full test cycle F or P appears and then display shuts off while monitoring the voltage reading on the voltmeter If the voltage drops below 7 5 at any time during the cycle the 9 volt tester battery must be replaced Use an extended life alkaline battery To replace the battery remove the outer set of screws on the faceplate and carefully lift the panel from the body Unplug the connector and pull battery with mounting tape off the back of the tester Attach the connector to the new battery and mount the battery to the case with double backed tape Reinstall the faceplate and secure with the four screws To Test Using 25 761 40 S Tester DSAM ASAM Test Procedure NOTE The SAM must be at room temperature when tested Disconnect all of the SAM leads isolating it from the main wiring harness and the ignition module s Testing may be performed with the module mounted or loose The figures show the part remo
146. de the valve in a straight line This may result in burnt valve faces or seats loss of compression and excessive oil consumption To check valve guide to valve stem clearance thoroughly clean the valve guide and using a split ball gauge measure the inside diameter of the guide Then using an outside micrometer measure the diameter of the valve stem at several points on the stem where it moves in the valve guide Use the largest stem diameter to calculate the clearance by subtracting the stem diameter from the guide diameter If the intake clearance exceeds 0 038 0 076 mm 0 0015 0 0030 in or the exhaust clearance exceeds 0 050 0 088 mm 0 0020 0 0035 in determine whether the valve stem or guide is responsible for the excessive clearance The maximum I D wear on the intake valve guide is 7 134 mm 0 2809 in while 7 159 mm 0 2819 in is the maximum allowed on the exhaust guide The guides are not removable but can be reamed 0 25 mm 0 010 in oversize Valves with 0 25 mm oversize stems must then be used If the guides are within limits but the valve stems are worn beyond limits install new valves Valve Seat Inserts Hardened steel alloy intake and exhaust valve seat inserts are press fitted into the cylinder head The inserts are not replaceable but can be reconditioned if not too badly pitted or distorted If cracked or badly warped the cylinder head should be replaced Recondition the valve seat inserts following
147. disconnected in Step 2 may be reconnected If the procedure was unsuccessful see Steps a and b following a If during this procedure the MIL goes back into blinking 4 consecutive blinks every 2 seconds the engine and O sensor have cooled down and out of closed loop operation prohibiting the learning from occurring Repeat Steps 6 9 b If during the procedure with the engine running the MIL stays on continuously for more than 15 seconds turn off the ignition Then initiate the fault code sequence by doing three consecutive key on key off cycles leaving the key on in the last sequence each key on key off sequence must be less than 2 5 seconds long The fault detected must be corrected before the auto learn function can be re initiated The PC based diagnostic tool and software may be used to read out the fault code and assist with the troubleshooting and repair 5B 10 Engine Oil Temperature Sensor Figure 5B 10 Engine Oil Temperature Sensor General The engine oil temperature sensor Figure 5B 10 is used by the system to help determine fuel requirements for starting a cold engine needs more fuel than one at or near operating temperature Mounted in the oil filter adapter housing it has a temperature sensitive resistor that extends into the oil flow The resistance changes with oil temperature altering the voltage sent to the ECU Using a table stored in its memory the ECU correlate
148. dy and removable venturi Impco carburetor for cracks holes and other wear or damage Check the choke shaft Nikki carburetor only and the throttle shaft for wear and free movement NOTE Do not attempt to disassemble or remove either shaft from the carburetor body including the mounted clamp brackets on Impco style carburetors The screws attaching the choke and throttle plate to their respective shafts are staked or bonded to prevent loosening The plate s and shaft s are not available separately If detrimental wear or damage is found in any of the parts the carburetor should be replaced 5A 5 Section 5A LPG Fuel Systems LPG Carburetor Reassembly Impco Carburetor 1 Slide the venturi into the carburetor body aligning the position mark made prior to removal Correctly installed the discharge holes should not be visible from the top 2 Secure with the venturi retaining screw Torque the screw to 4 0 N m 36 in Ib 3 Install a new adapter gasket and mount the air cleaner adapter onto the carburetor with the four screws Torque the screws to 4 0 N m 36 in Ib 4 Install a new carburetor gasket onto the intake manifold adapter followed by the carburetor Install and finger tighten the mounting fasteners 5 Connect the Z end of the throttle linkage and the dampening spring to the throttle clamp bracket on the throttle shaft Attach the opposite end of linkage and spring to the governor lever
149. e Electric Starter the gap to 0 76 mm 0 030 in for all except NG CD Fixed or 0 51 mm 0 020 in for NG CD Fixed Spark Plugs by carefully bending the ground electrode See Engine misfire or starting problems are often caused Figure 8 1 by aspark plug that has improper gap or is in poor condition Wire Gauge The engine is equipped with the following spark plugs Spark Plug Type The standard spark plug is a Champion RC12YC Kohler Part No 12 132 02 S Natural gas NG or RFI compliant engines use Champion XC12YC Kohler 25 132 14 S spark plug A high performance spark plug Champion Platinum 3071 used on Pro Series engines Kohler Part No 25 132 12 S is also available Equivalent alternate brand plugs can also be used Gap 0 76 mm 0 030 in all except NG CD Fixed 0 51 mm 0 020 in NG CD Fixed Thread Size 14mm dian de Reach 19 1 mm 3 4 in Hex Size 15 9 mm 5 8 in Figure 8 1 Servicing Spark Plug Spark Plug Service Every 200 hours of operation remove each spark plug Check its condition and either reset the gap or replace with a new plug as necessary To service the plugs perform the following steps 4 Reinstall the spark plug into the cylinder head and torque to 24 4 29 8 N m 18 22 ft Ib Inspection Inspect each spark plug as it is removed from the cylinder head The deposits on the tip are an indication of the general condition of the piston rings valves and carburetor 1 Bef
150. e Fick cobra Ferrea feratur adinamia 9 9 N m 88 in Ib Yellow or Brown O Ring Style Cover w Integral Metal Spacers 6 2 N m 55 in Ib Valves and Valve Lifters Hydraulic Valve Lifter to Crankcase Running Clearance 0 0241 0 0501 mm 0 0009 0 0020 in Intake Valve Stem to Valve Guide Running Clearance 0 038 0 076 mm 0 0015 0 0030 in Exhaust Valve Stem to Valve Guide Running Clearance 0 050 0 088 mm 0 0020 0 0035 in Intake Valve Guide I D lU 7 038 7 058 mm 0 2771 0 2779 in DIRE VDO CUTIE ireto cti aac rri ceased di gU opat itid se SU E EUN Ee dUes 7 134 mm 0 2809 in Exhaust Valve Guide I D TNC 7 038 7 058 mm 0 2771 0 2779 in Mae Vear IDEE urnis a i a a cea dues 7 159 mm 0 2819 in Valve Guide Reamer Size OE AMM du o MEER T E t o Oo 0 E 7 048 mm 0 2775 in OZ a io T 7 298 mm 0 2873 in Intake Valve Minimum Lifi oa oddieeoiee io e dutudo desse tenute iie nan iiai riedni 8 07 mm 0 3177 in Exhaust Valve Minimum Lift Lauer otav de rsaqi onde oed a pix Eon dpa l Repu acida e ctae E a ds 8 07 mm 0 3177 in Nonunal Valve peal ANGIE cisrenan ae a Un EQUUM FANE EIU DENM dE 45 Section 1 Safety and General Information General Torque Values Metric Fastener Torque Re
151. e Inner Baffles and Breather Cover cover with a screwdriver to break the RTV or The inner valley baffles are attached at one corner gasket seal See Figure 9 41 Do not pry on the using the same fasteners as the breather cover See sealing surfaces ds it could QUE damage Figure 9 39 resulting in leaks Most engines use a formed gasket rather than RTV sealant 1 Remove the two hex flange screws securing the inner baftles 9 10 Section 9 Disassembly 7 Remove the hex flange screw breather reed retainer and breather reed See Figure 9 44 d j Fi g W 1 r s E s 5 b x 3 i LES et k E i 1 Ehe t ai Fn E pa a k a Figure 9 41 Breaking Breather Cover Seal 5 Remove the breather cover and gasket if used See Figure 9 42 Remove Valve Covers Three valve cover designs have been used The earliest type used a gasket and RTV sealant between the cover and sealing surface of the cylinder head The second type had a black O Ring installed in a groove on the underside of the cover and may have metal spacers in the bolt holes The latest design uses a brown O Ring and the bolt holes spacers are molded in place 1 Remove the four hex flange screws securing each valve cover Note the position of any attached n brackets or lifting straps Figure 9 42 Removing Breather Cover 2 Remove the valve covers valve cover gaskets or O Rings and any brackets or lifting straps
152. e causing factors Refer to the specific section s within this service manual for more detailed information Engine Cranks But Will Not Start 1 Empty fuel tank Fuel shut off valve closed Poor fuel dirt or water in the fuel system Clogged fuel line Spark plug lead s disconnected Key switch or kill switch in off position Faulty spark plugs Faulty ignition module s Carburetor solenoid malfunction Diode in wiring harness failed in open circuit mode Vacuum fuel pump malfunction or oil in vacuum hose 13 Vacuum hose to fuel pump leaking cracked 14 Battery connected backwards 15 Safety interlock system engaged rm DO US SELON ae Sl mM m n Engine Starts But Does Not Keep Running 1 Restricted fuel tank cap vent 2 Poor fuel dirt or water in the fuel system 3 Faulty or misadjusted choke or throttle controls 4 Loose wires or connections that short the kill terminal of ignition module to ground Faulty cylinder head gasket Faulty carburetor 7 Vacuum fuel pump malfunction or oil in vacuum hose 8 Leaking cracked vacuum hose to fuel pump 9 Intake system leak o o SMART SPARK malfunction applicable models 10 Diode in wiring harness failed in open circuit mode Engine Starts Hard 1 11 12 13 c Mesue AS eS dd PTO drive is engaged Dirt or water in the fuel system Clogged fuel line Loose or faulty wires or connections Faulty or misadjusted choke o
153. e end of metal mounting clips are up out the commutator armature The mounting screw holes in the metal clips must be up c Install the brush springs and snap on the four out Slide the brush holder assembly down retainer caps See Figure 8 73 into place around the commutator and install the positive brush lead grommet in the cutout of the frame See Figure 8 71 The protective tube may be saved and used for future servicing Figure 8 73 Brush Installation Tool with Extension d Hold the starter assembly vertically on the end housing and carefully place the tool Figure 8 71 Installing Brush Holder Assembly with with extension and assembled original brush Supplied Tube holder assembly onto the end of the armature shaft Slide the brush holder assembly down Starter reassembly when not replacing the Brushes into place around the commutator install the Brush Holder Assembly positive brush lead grommet in the cutout of the frame See Figure 8 74 a Carefully unhook the retaining caps from over each of the brush assemblies Do not lose the springs 8 42 Section 8 Electrical System and Components Figure 8 74 Installing Brush Holder Assembly Figure 8 76 Torquing Brush Holder Screws using Tool with Extension 13 Hook the plunger behind the upper end of 11 Install the end cap onto the armature and frame the drive lever and install the spring into the aligning the thin raised rib in the end cap
154. e in the fuel warning on page 5B 2 Remove the two fuel rail mounting screws 14 Clean any dirt accumulation from the sealing mounting area of the faulty injector s and disconnect the electrical connector s 15 Pull the retaining clip off the top of the injector s and remove from manifold 16 Reverse the appropriate procedures to install the new injector s and reassemble the engine Use new O Rings any time an injector is removed new replacement injectors include new O Rings Lubricate O Rings lightly with oil Torque the fuel rail and blower housing mounting screws to 3 9 N m 35 in Ib and the intake manifold and air cleaner mounting screws to 9 9 N m 88 in Ib Injector problems due to dirt or clogging are generally unlikely due to the design of the injectors the high fuel pressure and the detergent additives in the gasoline Symptoms that could be caused by dirty clogged injectors include rough idle hesitation stumble during acceleration or triggering of fault codes related to fuel delivery Injector clogging is usually caused by a buildup of deposits on the director plate restricting the flow of fuel resulting in a poor spray pattern Some contributing factors Section 5B EFI Fuel System to injector clogging include higher than normal operating temperatures short operating intervals and dirty incorrect or poor quality fuel Cleaning of clogged injectors is not recommended they should be repl
155. e low idle fuel adjusting needles out counterclockwise from the preliminarysetting until the engine speed decreases rich Note the position of the needle Now turn the adjusting needle in clockwise The engine speed may increase then it will decrease as the needle is turned in lean Note the position of the needle Set the adjusting needle midway between the rich and lean settings See Figure 5 12 b Repeat the procedure on the other low idle adjustment needle 4 Recheck adjust the Low Idle Speed RPM to the specified setting Lean Lean Adjust to Midpoint Right Side Adjust to Midpoint Left Side Figure 5 12 Optimum Low Idle Fuel Settings Models with Governed Idle System An optional governed idle control system is supplied on some engines The purpose of this system is to maintain a desired idle speed regardless of ambient conditions temperature parasitic load etc that may change Engines with this feature contain a small secondary spring connected between the governor lever and the lower adjustment tab of the main bracket See Figure 5 13 The system requires an additional procedure for setting the idle speed If speed adjustments are required proceed as follows 1 Make any necessary speed or control adjustments following the appropriate instructions covered in this section Section 5 Fuel System and Governor 2 Move the throttle control to the idle position Carburetor Servicing
156. e the four screws in two stages first to 7 4 N m 66 in Ib then to 9 9 N m 88 in Ib using the sequence shown in Figure 11 51 Figure 11 51 Intake Manifold Torque Sequence Section 11 Reassembly Figure 11 52 Sealant Applied to Terminals NOTE If the wires were disconnected from the ignition modules on engines with SMART SPARK reattach the leads and seal the base of the terminal connectors with GE Novaguard G661 see Section 2 or Fel Pro Lubri Sel dielectric compound The beads should overlap between the terminals to form a solid bridge of compound See Figure 11 52 Do not put any compound inside the terminals The 24 584 15 5 ignition modules have a separator barrier between the terminals On these modules seal the base of the terminals but it is not necessary to have overlapping beads of sealant between the connections 2 Two Barrel Manifold Carburetor Models Route the wiring harness through the mounting clip on the underside of debris shield if separated earlier Carefully position the debris shield to the rear as far as possible See Figure 11 53 Figure 11 53 Routing of Wiring Harness Two Barrel Models 11 15 Section 11 Reassembly 3 Connect the kill lead to the tab terminal on 3 Install the breather reed and breather reed standard ignition modules See Figure 11 54 retainer onto the crankcase and secure with the hex flange screw Hold the assembly in line when tightening T
157. eads Shut Off Fuel Supply Drain Oil from Crankcase and Remove Oil Filter 1 Remove the oil fill cap dipstick and one of the oil drain plugs 9 1 Section 9 Disassembly 3 Remove and discard the oil filter See Figure 9 5 Figure 9 4 Removing Oil Drain Plug Figure 9 6 Removing Oil Filter Adapter Nipple 2 Allow ample time for the oil to drain from the crankcase and oil filter 9 2 Section 9 Disassembly 4 Remove the hex flange screws securing the bracket and base See Figure 9 8 Two additional rear screws must be removed if the engine contains a rear air cleaner support bracket See Figure 9 9 Figure 9 7 Removing Oil Cooler 4 Anoilcooler is standard equipment on some models and an option on others It may be a cast aluminum housing part of the oil filter adapter or attached to the blower housing separated from the oil filter adapter If so equipped remove the adapter and the cooler See Figures 9 6 and Figure 9 9 Rear Air Cleaner Bracket Screws 9 7 5 Remove the bracket then remove the base and Remove Muffler gasket while carefully pulling the rubber 1 Remove the exhaust system and attaching breather tube through the base See Figure 9 10 hardware from the engine On engines equipped with a port liner remove it now Remove Air Cleaner Assembly Standard Air Cleaner 1 Unhook the latches or loosen the knob and remove the cover Refer to Section 4 2 Remove the wing nut from
158. ecommended 1 If using the gasket or sealant type cover prepare the sealing surfaces of the cylinder head and cover as directed in Service Bulletin 252 Refer to Section 2 for approved sealants Always use fresh sealant using outdated sealant could result in leakage With O Ring type covers make sure the sealing surfaces are clean 2 Make sure there are no nicks or burrs on the sealing surfaces 3 For covers requiring RTV sealant apply a 1 5 mm 1 16 in bead to the sealing surface of both cylinder heads install a new valve cover gasket on each then apply a second bead of sealant on the top surface of the gaskets For O Ring type covers install a new O Ring in the groove of the covers Do not use gaskets or RTV sealant 4 Locate the cover with the oil fill neck on the same side as removed and install the lifting strap in the original position With O Ring type covers position the cover on the cylinder head If loose spacers were used insert a spacer in each of the screw holes On both types install the four hex flange screws in each cover and finger tighten 5 Torque the valve cover fasteners to the proper specification using the sequence shown in Figure 11 89 Section 11 Reassembly Gasket RTV style cover 3 4 N m 30 in Ib Black O Ring style cover with shoulder screws 5 6 N m 50 in Ib with screws and spacers 9 9 N m 88 in Ib Yellow or Brown O Ring style cover wi
159. ection 5 Fuel System and Governor Main High Speed Circuit At high speeds loads the engine operates on the main circuit As a metered amount of air is drawn through the four air jets fuel is drawn through the main jets The air and fuel are mixed in the main nozzles and then enter the main body of airflow where further mixing of the fuel and air occurs This mixture is then delivered to the combustion chamber The carburetor has a fixed main circuit no adjustment is possible Carburetor Adjustments Adjustment NOTE Carburetor adjustments should be made only after the engine has warmed up The carburetor is designed to deliver the correct fuel to air mixture to the engine under all operating conditions The main fuel jet is calibrated at the factory and is not adjustable The idle fuel adjusting needle is also set at the factory and normally does not need adjustment Depending on model and application engines may also be equipped with a Governed Idle System If equipped with a Governed Idle System refer to Models with Governed Idle System when performing any carburetor adjustment as an additional step to the listed adjustment procedure s is required NOTE Engines operating at altitudes above approximately 1219 m 4000 ft may require a special high altitude main jet Refer to High Altitude Operation If however the engine is hard starting or does not operate properly it may be necessary to
160. ee Figure 8 67 Figure 8 67 Installing Armature and Pivot Lever Section 8 Electrical System and Components Install the backup washer followed by the rubber grommet into the matching recess of the drive end cap The molded recesses in the grommet should be out matching and aligned with those in the end cap See Figure 8 68 Figure 8 68 Installing Backup Washer and Grommet 8 Install the frame with the small notch forward onto the armature and drive end cap Align the notch with the corresponding section in the rubber grommet Install the drain tube in the rear cutout if it was removed previously See Figure 8 69 Figure 8 69 Installing Frame and Drain Tube 9 Install the flat thrust washer onto the commutator end of the armature shaft See Figure 8 70 8 41 Section 8 Electrical System and Components Figure 8 70 Installing Thrust Washer Figure 8 72 Removing Retaining Clips 10 Starter reassembly when replacing the Brushes b Position each of the brushes back in their slots Brush Holder Assembly so they are flush with the LD of the brush holder assembly Insert the Brush Installation a Hold the starter assembly vertically on the Tool with extension or use the tube described end housing and carefully position the above from a prior brush installation through assembled brush holder assembly with the the brush holder assembly so the holes in the supplied protective tube against th
161. egulator avoid losing them on the blower housing See Figure 9 31 Remove Oil Sentry If So Equipped 1 Disconnect the lead from the Oil Sentry switch 2 Remove the Oil Sentry switch from the breather cover See Figure 9 29 Figure 9 31 Disconnecting Plug from Rectifier Regulator 2 Usethe tip of the dipstick or a similar small flat tool to bend the locking tang then remove the B center lead from the terminal plug as shown in Figure 9 32 This will allow the blower housing to Breather Cover be removed without disturbing the wiring harness Remove Electric Starter Motor 1 Disconnect the leads from the starter 2 Remove the two hex flange screws See Figure 9 30 Figure 9 32 Remove B Lead from Terminal Plug 3 The rectifier regulator does not have to be detached from the blower housing If the engine is equipped with SMART SPARK the SAM Figure 9 30 Removing Electric Starter Motor module should be removed from the cylinder baffle or blower housing See Figure 9 33 The 3 Remove the starter assembly and any spacers if module willing hang loose as part of the wiring used harness 9 8 Section 9 Disassembly Figure 9 35 Removing Outer Baffles 5 Remove the outer baffles on both sides See Figure 9 35 6 Onengines equipped with a metal grass screen remove the screen before removing the blower housing See Figure 9 36 Plastic grass screens can be removed after the blower
162. egulators 8 18 Section 8 Electrical System and Components 4epupA2 e Bnid eds a 11 P i 1 Alquiess y 0 109 jooymA 4 D e lh gs eijnpow uonjubj uonub Jepun o2 YMS ensseJd IIO Ii SUUM uee15 m Knues IO 390g 10 2euuo5 tul 14817 evoueu Aur oued vu Aus IO 10 s nS ou 191901 uomub 8 PAOA jquiessy saun unis pjouajos ueelsy IM wARUES IO 0 403 PH ut 9 a Kini uopiub eyeuieq y 7 piousjos O usus cun S 19485 84n 89Jd llO 9UUuM pns piousjos feujuuo Arossacoy til MONA pe e 4 IH saneben i MO A hueneg i j e nisod 4 4 5 EN E een Joppauuop IE oyeuBey W po 660 Sz uouMs A9 J9499H H 19j4O0 UNS 01 1no e v0 660 SZ LO S61 Bp 10 2euuo um M MONA Miossacoy V Koneg g S n SUM 84 S punog aM sai enn youms 9y peu IM peu enig Figure 8 23 Wiring Diagram 15 20 25 Amp Regulated Battery Charging System with Fixed Timing 8 19 Section 8 Electrical System and Components g 19J0IA jquiessy saun HIUS piousjos uee15 HIM w nues IO Xp Eno yoojg 1012euuo2 J0jejn6oH nt KL 1epuy 2 zi uopiub eyeujey v Bnid 31eds s0jejnBey O Xa Co piousjos Jeyioeu NIMS JUAS 841n 89Jd tO SUUM SWYS ley iq uo xuld pnis SINVS Bojeuy uo Mola piouejJos 1918s jeujuuo Aiossasoy 1 my IH
163. en internal engine temperatures approach the welding point of the piston Temperatures high enough to do this are created by friction which is usually attributed to improper lubrication and or overheating of the engine Normally very little wear takes place in the piston boss piston pin area If the original piston and connecting rod can be reused after new rings are installed the original pin can also be reused but new piston pin retainers are required The piston pin is included as part of the piston assembly if the pin boss in the piston or the pin are worn or damaged a new piston assembly is required Section 10 Inspection and Reconditioning Ring failure is usually indicated by excessive oil Detonation damage occurs when a portion of the fuel consumption and blue exhaust smoke When rings charge ignites spontaneously from heat and pressure fail oil is allowed to enter the combustion chamber shortly after ignition This creates two flame fronts where it is burned along with the fuel High oil which meet and explode to create extreme hammering consumption can also occur when the piston ring end pressures on a specific area of the piston Detonation gap is incorrect because the ring cannot properly generally occurs from using low octane fuels conform to the cylinder wall under this condition Oil control is also lost when ring gaps are not staggered Preignition or ignition of the fuel charge before the during installation timed spark c
164. engine speed does not exceed 3750 RPM no load Connect Spark Plug Leads p 1 Connect the leads to the spark plugs See Figure 11 106 Figure 11 106 Connect Spark Plug Leads 11 31 Section 11 Reassembly 11 32 Section 12 Clutch Clutch General Some engines are equipped with a wet disc type clutch See Figure 12 1 for exploded view of clutch Nameplate Shifting Lever j Pin Oil Seal Ball Bearing Snap Ring Pressure Plate S Retaining Rings Pilot Bearin Release 3 Sleeve Clutch Assembly Assembly c Bearing Release Adjusting H B Assembly Lock Figure 12 1 Wet Type Clutch Exploded View 12 1 Section 12 Clutch Service 2 After adjustment is made engage clutch and On this type an oil splash type lubrication system is check to make sure rollers go over center to lock used The proper oil level must be maintained to the unit in engaged position and prevent provide efficient lubrication The oil should be releasing under load If trouble persists after changed after each 100 hours of operation When readjustment clutch reconditioning is indicated refilling use 0 47 L 1 pt of motor oil of proper viscosity See chart below Reconditioning Drain the oil remove the nameplate and use the SAE Viscosity following procedure Above 10 C 50 F SAE 30 1 Remove capscrews 2 from clutch yoke and 17 8 C 0 to 10 C 50 F SAE 20 remove spacers Below
165. engine is reassembled and placed into operation Even small amounts of these cleaners can quickly break down the lubricating properties of engine oil Typical Disassembly Sequence The following sequence is suggested for complete engine disassembly The sequence can be varied to accommodate options or special equipment Disconnect spark plug leads Shut off fuel supply Drain oil from crankcase and remove oil filter Remove muffler Remove air cleaner assembly Remove fuel pump Remove control panel if so equipped Remove throttle and choke controls 9 Remove external governor controls 10 Remove carburetor 11 Remove Oil Sentry if so equipped 12 Remove electric starter motor 13 Remove outer baffles and blower housing 14 Remove inner baffles and breather cover 15 Remove valve covers 16 Remove ignition modules 17 Remove intake manifold 18 Remove spark plugs 19 Remove cylinder heads and hydraulic lifters oe ae Ier 20 Remove grass screen and fan 21 Remove flywheel 22 Remove stator and backing plates 23 Remove closure plate assembly 24 Remove camshaft 25 Remove connecting rods with pistons and rings 26 Remove crankshaft 27 Remove governor cross shaft 28 Remove flywheel end oil seal Disconnect Spark Plug Leads 1 Disconnect the leads from the spark plugs See Figure 9 1 NOTE Pull on boot only to prevent damage to spark plug lead Figure 9 1 Disconnect Both Spark Plug L
166. engines have a combination system which allows the operator to select either gasoline or LP This section covers the standard carbureted fuel systems The gaseous systems are covered in subsection 5A and the EFI systems are covered in subsection 5B The governor systems used are covered at the end of this section A WARNING Explosive Fuel Gasoline is extremely flammable and its vapors can explode if ignited Store gasoline only in approved containers in well ventilated unoccupied buildings away from sparks or flames Do not fill the fuel tank while the engine is hot or running since spilled fuel could ignite if it comes in contact with hot parts or sparks from ignition Do not start the engine near spilled fuel Never use gasoline as a cleaning agent Fuel System Components The typical carbureted fuel system and related components include the following Fuel Tank Fuel Lines In line Fuel Filter Fuel Pump Carburetor Operation The fuel from the tank is moved through the in line filter and fuel lines by the fuel pump On engines not equipped with a fuel pump the fuel tank outlet is located above the carburetor inlet allowing gravity to feed fuel to the carburetor Fuel then enters the carburetor float bowl and is drawn into the carburetor body There the fuel is mixed with air This fuel air mixture is then burned in the engine combustion chamber Fuel Recommendations General Recommendations Purchase gasoline in sma
167. entiometer varying the voltage signal to the ECU in direct correlation to the angle of the throttle plate This signal along with the other sensor signals is processed by the ECU and compared to the internal preprogrammed maps to determine the required fuel and ignition settings for the amount of load The correct position of the TPS is established and set at the factory Do not loosen the TPS or alter the mounting position unless absolutely required by fault code diagnosis or throttle shaft service If the TPS is loosened or repositioned the appropriate TPS Initialization Procedure pages 5B 8 5B 10 must be performed to reestablish the baseline relationship between the ECU and the TPS Service The TPS is a sealed non serviceable assembly If diagnosis indicates a bad sensor complete replacement is necessary If a blink code indicates a problem with the TPS it can be tested as follows 1 Counting the number of turns back out the idle 1 Throttle Valve Shaft speed adjusting screw counterclockwise until 2 Resistor Track the throttle plates can be closed completely 3 Wiper Arm w Wiper 4 Electrical Connection 2 Disconnect the main harness connector from the ECU but leave the TPS mounted to the throttle Figure 5B 6 Throttle Position Sensor Details body manifold General 3 Connect the ohmmeter leads as follows The throttle position sensor TPS is used to indicate See chart on pages 5B 28 5B 31 or 5B 32
168. er key off then key on code 56 would be set also Fuel pump relay pin 87 to injector pin 1 b Opened main fuse F1 3 Fuel Pump Relay Related a Bad fuel pump relay Primary side functional but pin 30 to pin 87 remains open Primary side pin 85 to pin 86 is open or shorted during engine operation Note after key off then key on code 56 would be set also 4 ECU Related a Circuit controlling injector 2 damaged b Circuit controlling fuel pump relay damaged Code 55 32 Pin MSE 1 1 Plastic Cased ECU only Source MIL Diagnostic lamp circuit open shorted to ground or shorted to battery Explanation MIL is not functioning because the circuit is open shorted to ground or shorted to battery Expected Engine Response Engine will run normally if no other errors are present Possible Causes 1 MIL diagnostic lamp Related a MIL element opened or element shorted to ground b Lamp missing 2 Engine Wiring Harness Related a Broken or shorted wire in harness ECU pin 29 to lamp open or shorted 3 Vehicle Wiring Harness Related a Broken or shorted wire in harness Power lead to MIL open or shorted 4 ECU Related a Circuit controlling lamp damaged Section 5B EFI Fuel System Code 56 32 Pin MSE 1 1 Plastic Troubleshooting Flow Chart Cased ECU only The following flow chart on page 5B 44 provides Source Fuel pump relay circuit open shorted an alternative method of troubleshooting the
169. er switch See Figure 8 30 The POWER light should be illuminated and one of the four status lights may be on as well This does not represent the condition of the part Figure 8 30 4 Press the TEST button until a click is heard and then release See Figure 8 31 Momentarily one of the four lights will illuminate indicating the condition of the part 8 23 Section 8 Electrical System and Components 3 Connect the red lead and one of the black leads to the pair of terminals on the open end of the n tandem adapter lead connections are not location a specific ec ORR i 4 Connect the remaining black lead from the tester RE SU e to one of the outer AC terminals on the rectifier TESTe regulator See Figure 8 33 Figure 8 31 a Ifthe OK green light comes on and stays steady the part is good and may be used b If any other light is displayed the rectifier regulator is faulty and should not be used NOTE A flashing LOW light can also occur Figure 8 33 as a result of an inadequate ground lead connection Make certain connection location 5 Plug the tester into the proper AC outlet power is clean and clamp is secure for tester being used Turn on the power switch The POWER light should be illuminated and Pi Amp Rectifier Regulators one of the four status lights may be on as well Connect the single lead adapter in between the See Figure 8 30 This does not represe
170. es If the solenoid fails to activate it should be replaced NOTE DO NOT leave the 12 volt test leads connected to the solenoid for any time over what is necessary for performing each of the individual tests Internal damage to the solenoid may otherwise occur 12 volt Test Leads Momentary Connection Only Figure 8 78 Testing Pull In Coil Plunger Actuation Test 2 Solenoid Pull In Coil Contact Continuity Test Use an ohmmeter set to the audible or Rx2K scale and connect the two ohmmeter leads to the two large post terminals Perform the preceding test 1 and check for continuity See Figure 8 79 The ohmmeter should indicate continuity if no continuity is indicated the solenoid should be replaced Repeat test several times to confirm condition 8 44 12 volt Test Leads Momentary Connection Only VOM Leads E r f imma l a Figure 8 79 Testing Pull In Coil Solenoid Contact Continuity Test 3 Solenoid Hold In Coil Function Test Connect one 12 volt test lead to the flat spade S start terminal on the solenoid and the other lead to the body or mounting surface of the solenoid Then manually push the plunger In and check if the Hold In coil holds the plunger retracted See Figure 8 80 Do not allow the test leads to remain connected to the solenoid for a prolonged period of time If the plunger fails to stay retracted the solenoid should be replaced Manually Push Plunger In 12
171. ester clip to a good engine ground NOTE Iftwo testers are available testing can be performed simultaneously for both cylinders However if only one tester is available two individual tests must be performed The side not being tested must have the spark plug lead connected or grounded Do not crank the engine or perform tests with one spark plug lead disconnected and not grounded or permanent system damage may occur 2 Crank the engine over establishing a minimum of 550 600 RPM and observe tester s for spark 3 Repeat the spark test on the opposite cylinder if cylinders are being tested individually a Ifboth cylinders have good spark but the engine runs poorly or existing plug condition or appearance is questionable install new spark plugs gapped at 0 76 mm 0 030 in and retest engine performance If problem persists go to Test 3 b If one cylinder had good spark but the other cylinder had no spark or intermittent spark go to Test 4 c If there was spark on both cylinders but power is suspect go to Test 3 Test 3 Check for Timing Advance 1 Makea line near the edge of the flywheel screen with a marking pen chalk or narrow tape See Figure 8 18 2 Connect an automotive timing light to cylinder that had good spark Figure 8 18 Mark for Timing Advance 3 Run the engine at idle and use the timing light beam to locate the line on the screen Draw a line on the blower housing next to the l
172. et Intake G Carburetor Manifold em intake Gasket s O O Ring intake Manifold Miete GM AE 9 Gii Se O Ring co Intake Manifold Manifold Figure 4 8 Exploded View of Standard Air Intake System Components 4 3 Section 4 Air Cleaner and Air Intake System Air Cleaner Element Cover and Seal Make sure element cover is not bent or damaged Make sure the wing nut and seal are in place to ensure the element is sealed against leakage Air Cleaner Base Make sure the base is secured tightly to the carburetor and not cracked or damaged Breather Tube Make sure the tube is attached to both the air cleaner base and the breather cover NOTE Damaged worn or loose air cleaner components can allow unfiltered air into the engine causing premature wear and failure Tighten or replace all loose or damaged components Rear Mounting Complete Disassembly and Reassembly Screws Standard Type If the base plate on the standard type has to be removed proceed as follows 1 Remove air cleaner components as described earlier 2 Remove the hex flange screws securing the bracket and base See Figures 4 9 and 4 10 Remove the bracket Figure 4 10 Rear Mounting Screws Used with 3 Pinch the sealing collar on the breather hose and Plastic Intake Manifold push it down through the hole in the air cleaner base Carefully feed the upper section of the breather tube down through the base See Figure 4 11 4 Remove t
173. ew with a small amount of Permabond LM 737 or equivalent Loctite adhesive Do not get any adhesive on free coils of spring 3 Start the engine and recheck the idle speed settings after sufficient warm up Readjust as required Initial Governor Adjustment The initial governor adjustment is especially critical on EFI engines because of the accuracy and sensitivity of the electronic control system Incorrect adjustment can result in overspeed loss of power lack of response or inadequate load compensation If you encounter any of these symptoms and suspect them to be related to the governor setting the following should be used to check and or adjust the governor and throttle linkage 5B 24 If the governor throttle components are all intact but you think there may be a problem with the adjustment follow Procedure A to check the setting If the governor lever was loosened or removed go immediately to Procedure B to perform the initial adjustment A Checking the Initial Adjustment 1 Unsnap the plastic linkage bushing attaching the throttle linkage to the governor lever See Figure 5B 37 Unhook the damper spring from the lever separate the linkage from the bushing and remove the bushing from the lever Mark the hole position and unhook the governor spring from the governor lever NV TA Lie LA N ity Throttle a uT LI d m ca NS sd U e 1 Linkage UL vs REST f A nhe as m n Figure 5B 37 Th
174. ews 11 with limiter and carburetor body are non serviceable items and should not be removed The choke shaft assembly is serviceable however it should not be removed unless a Choke Repair Kit will be installed Install the large flat retaining washer and secure with the mounting screw attaching the ground lead if originally secured by the screw Install the new idle speed RPM adjustment screw and spring onto the carburetor Thread in until 3 or 4 threads are exposed as an initial adjustment See Figure 5 27 5 16 Figure 5 27 Installing Idle Speed Adjusting Screw and Spring 12 Attach the inlet needle to the plastic tang of the float with the wire clip The formed 90 lip should point up with the needle valve hanging down See Figure 5 28 Figure 5 28 Float and Inlet Needle Details 13 Install the float and inlet needle down into the seat and carburetor body Install the new pivot pin through the float hinge and secure with the new retaining screw See Figure 5 29 Section 5 Fuel System and Governor Figure 5 29 Installing Float Assembly 14 Hold the carburetor body so the float assembly hangs vertically and rests lightly against the fuel inlet needle The inlet needle should be fully seated but the center pin of the needle on retainer clip end should not be depressed Check the float height adjustment NOTE The inlet needle center pin is spring loaded I9 Make sure the float rests
175. f clamp is closed Start the engine and run at no load high speed 3200 to 3750 RPM Open the clamp and note the water level in the tube The level in the engine side should be a minimum of 10 2 cm 4 in above the level in the open side If the level in the engine side is less than specified low no vacuum or the level in the engine side is lower than the level in the open side pressure check for the conditions in the table on page 3 4 Close the shut off clamp before stopping the engine To test the crankcase vacuum with the Vacuum Pressure Gauge Kit see Section 2 1 2 Remove the dipstick or oil fill plug cap Install the adapter into the oil fill dipstick tube opening upside down over the end of a small diameter dipstick tube or directly into engine a tube is not used Push the barbed fitting on the gauge solidly in the hole in the adapter Start the engine and bring it up to operating speed 3200 3600 RPM if to Check the reading on the gauge If the reading is to the left of 0 on the gauge vacuum or negative pressure is indicated If the reading is the right of 0 on the gauge positive pressure present Crankcase vacuum should be 4 10 inches of to 1S water If the reading is below specification or if pressure is present check the following table for possible causes and remedies 3 3 Section 3 Troubleshooting No Crankcase Vacuum Pressure i
176. fasteners 11 19 for sealant pattern in the sequence shown in Figure 11 21 to 24 4 N m 216 in Ib On some engines one of the ten mounting screws is plated The plated screw is typically installed in the 6 hole shown in Figure 11 21 Figure 11 21 Closure Plate Fastener Torque Sequence Figure 11 19 Closure Plate Sealant Pattern 4 Make sure the end of the governor cross shaft is lying against the bottom of cylinder 1 inside the crankcase See Figure 11 13 5 Install the closure plate to the crankcase Carefully seat the camshaft and the crankshaft into their mating bearings Rotate the crankshaft slightly to help engage the oil pump and governor gear meshes See Figure 11 20 Figure 11 22 Torquing Closure Plate Fasteners Install Stator and Backing Plates n 1 Apply pipe sealant with Teflon Loctite No 5924 or equivalent to the stator mounting holes 2 Position the stator aligning the mounting holes so that the leads are at the bottom towards the crankcase E al 3 Install and torque the two hex flange screws to Figure 11 20 Using Spanner Wrench to Turn 6 2 N m 55 in Ib See Figure 11 23 Crankshaft Section 11 Reassembly Install Flywheel WARNING Damaging Crankshaft and Flywheel Can Cause Personal Injury Using improper procedures to install the flywheel can crack or damage the crankshaft and or flywheel This not only causes extensive engine damage but can also cause personal in
177. from plastic or rubber parts if non compatible Use clean dry compressed air to blow out the internal channels and ports Do not use metal tools or wire to clean orifices and jets Inspect and thoroughly check the carburetor for cracks wear or damage Inspect the fuel inlet seat for wear or damage Check the spring loaded choke plate to make sure it moves freely on the shaft Clean the carburetor fuel bowl as required Install the two main nozzles into the towers of the carburetor body The end of the main nozzles with the two raised shoulders should be out down adjacent to the main jets Make sure the nozzles are completely bottomed Carefully install the main jets into the towers of the carburetor body on the appropriate side as identified when removal was performed See Figure 5 26 Nozzle End with Two Shoulders Out Down Main Jets Figure 5 26 Installing Main Nozzles and Main Jets Figure 5 25 Slow Jets and O Ring Detail 9 Make sure the O Ring near the bottom of each slow jet is new or in good condition Align and insert the two slow jets into the top of carburetor See Figure 5 25 5 Remove the idle speed RPM adjustment screw and spring from the carburetor Discard the parts NOTE The carburetor is now disassembled for 10 appropriate cleaning and installation of the parts in the overhaul Kit Further disassembly is not necessary The throttle shaft assembly fuel inlet seat idle fuel adjustment scr
178. fset incorrect TPS faulty Faulty engine temperature sensor Faulty injectors Engine misses hesitates or stalls under load 1 DUE I e Fuel injector s fuel filter fuel line or fuel pick up dirty restricted Dirty air cleaner Insufficient fuel pressure or fuel delivery Vacuum intake air leak Improper governor setting adjustment or operation Speed sensor malfunction TPS faulty mounting problem or TPS Initialization Procedure incorrect 8 Bad coil s spark plug s or wires Low Power 1 Faulty malfunctioning ignition system PS Pg Moe Dirty air filter Insufficient fuel delivery Improper governor adjustment Plugged restricted exhaust One injector not working Basic engine problem exists TPS faulty or mounting exists Throttle plates in throttle body intake manifold not fully opening to WOT stop if so equipped Electrical System The EFI system is a 12 VDC negative ground system designed to operate down to a minimum of 7 0 volts If system voltage drops below this level the operation of voltage sensitive components such as the ECU fuel pump and injectors will be intermittent or disrupted causing erratic operation or hard starting A fully charged 12 volt battery with a minimum of 350 cold cranking amps is important in maintaining steady and reliable system operation Battery condition and state of charge should always be checked first when troubleshooting an operational problem Keep in mind
179. fuel is not visible after 10 seconds stop cranking and allow the starter to cool for 60 seconds Priming Without a Test Valve in Fuel Rail 1 Crank the engine in 10 15 second intervals allowing a 60 second cool down period between cranking intervals until the engine starts NOTE The number of cranking intervals necessary will depend on the individual system design and or where the system has been disassembled Fuel Recommendations General Recommendations Purchase gasoline in small quantities and store in clean approved containers An approved container with a capacity of 2 gallons or less with a pouring spout is recommended Such a container is easier to handle and helps prevent spillage during refueling e Do not use gasoline left over from the previous season to minimize gum deposits in your fuel system and to ensure easy starting e Do not add oil to the gasoline e Do not overfill the fuel tank Leave room for the fuel to expand Fuel Type For best results use only clean fresh unleaded gasoline with a pump sticker octane rating of 87 R M 2 or higher In countries using the Research Octane Number RON it should be 90 octane minimum Leaded gasoline is not recommended and must not be used on EFI engines or on other models where exhaust emissions are regulated Gasoline Alcohol blends Gasohol up to 1076 ethyl alcohol 9076 unleaded gasoline by volume is approved as a fuel for Kohler engines Other gasol
180. g an stator is OK ohmmeter If resistance is 0 ohms stator is shorted Replace stator If resistance is infinity ohms stator or lighting lead is open Replace stator 8 28 Section 8 Electrical System and Components Electric Starting Motors NOTE If the starter does not crank the engine shut Some engines in this series use inertia drive starting off the starter immediately Do not make motors while most use solenoid shift starters The further attempts to start the engine until the inertia drive types are covered first and the solenoid condition is corrected shift types following NOTE Do not drop the starter or strike the starter Starting Motor Precautions frame Doing so can damage the starter NOTE Do notcrank the engine continuously for more than 10 seconds at a time If the engine does not start allow a 60 second cool down period between starting attempts Failure to follow these guidelines can burn out the starter motor Starter Removal and Installation Refer to the Disassembly and Reassembly Sections for starter removal and installation procedures Inertia Drive Electric Starters NOTE If the engine develops sufficient speed to This subsection covers the operation troubleshooting disengage the starter but does not keep and repair of the inertia drive permanent magnet running a false start the engine rotation electric starters must be allowed to come to a complete stop before attempting to res
181. ging lead disconnected from battery 3 If resistance is low in both directions the diode and engine stopped measure resistance from is shorted Replace the diode charging lead to ground using an ohmmeter Note reading If resistance is high in both directions the diode or stator winding is open Use Test 4 Reverse the leads and measure resistance again In one direction the resistance should be infinity ohms open circuit With the leads reversed some resistance should be measured about midscale on Rx1 range 4 Cutthe sleeving on the charging lead to exposd 4 Ifresistance is approximately 1 07 ohms the diode connections stator winding is OK Measure the resistance from the stator side of If resistance is 0 ohms stator winding is shorted diode to ground using an ohmmeter Replace stator If resistance is infinity ohms stator winding or lead is open Replace stator 1 Make sure lights are not burned out 1 Replace burned out lights 2 Disconnect the lighting lead from the wiring 2 If voltage is 15 volts or more stator is OK Check harness for loose connections or shorts in wiring harness With engine running at 3000 RPM measure If voltage is less than 15 volts test stator using No voltage from lighting lead to ground using an an ohmmeter Test 3 Lights AC voltmeter With engine stopped measure the resistance 3 If resistance is approximately 0 4 ohms of stator from lighting lead to ground usin
182. h one containing a white stripe Do not connect to the black white lead with the bullet connector or a Fail test result will occur regardless of actual condition Caution Do not allow alligator clip leads to touch each other 2 Recheck the SAM part number noting the last two digits Refer to the table below or on the tester faceplate to determine the test number to be used SAM A a Ds 24 584 50 24 55133 2458432 Part No 54 254 05 24 58431 24 58434 SAM Part No tt Depress the tester button repeatedly until the correct test number appears on the display After a few seconds the test number will flash three times and the test will begin A reverse numerical sequence will be displayed starting with a 6 and progressing down to 1 followed by a P pass or F fail indicating the condition of the part See Figures 8 15 and 8 16 If testing an ASAM return to step 1 and move the yellow and brown tester leads to the short set of module leads then repeat the test 24 584 18 24 584 38 Mh dd 4 If you get a sign instead of the numerical sequence and or an F at the end of the test cycle recheck all of the connections check the condition of the tester battery and repeat the test If you get the or F sign again in the retest replace the SAM IMPORTANT Allow 15 20 seconds for the tester to clear and reset itself between tests or if the test is interrupted before completion
183. have an authorized Kohler dealer install a special high altitude jet kit in the carburetor If a high altitude kit has been installed the engine must be reconverted to the original jet size before it is operated at lower altitudes or overheating and engine damage can result To obtain high altitude kit information or locate a dealer near you call 1 800 544 2444 to find the names of the nearest Kohler Co Service Centers or access our web site at www kohlerengines com and click on the Service amp Dealer Locator located in the upper right hand corner The service center will need your engine specification number which is found on your Engine ID Label Section 5 Fuel System and Governor Fuel Shut off Solenoid Most carburetors are equipped with a fuel shut off solenoid The solenoid is attached in place of the fixed main jet screw on the flywheel side of the carburetor See Figure 5 3 The solenoid has a spring loaded pin that retracts when 12 volts is applied to the lead allowing fuel flow through the main jet When current is removed the pin extends blocking the main fuel jet and preventing fuel from entering the carburetor One Barrel Carburetor 3 J 9 j d 1 az y e 2 NF k at t v Fuel Shut off Solenoid zz5 Two Barrel Carburetor Fuel Shut off Solenoid Figure 5 3 Fuel Shut off Solenoid Below is a simple test made with the engine off that can determine if the solenoid is functi
184. he base and gasket 5 Reverse the procedure to reinstall new or serviced components Torque screws to 9 9 N m 88 in Ib Heavy Duty Air Cleaner General The heavy duty air cleaner consists of a cylindrical housing typically mounted to a bracket off the upper valve cover screws and connected with a formed rubber hose to an adapter on the carburetor or throttle body intake manifold EFI units The air cleaner housing contains a paper element and inner element designed for longer service intervals The system is CARB EPA certified and the components should not be altered or modified in any way Figure 4 11 Breather Tube Air Cleaner Components Whenever the air cleaner cover is removed or the paper element or precleaner are serviced check the following 4 4 Section 4 Air Cleaner and Air Intake System 4 Do not wash the paper element and inner element or use compressed air this will damage the elements Replace dirty bent or damaged elements with new genuine Kohler elements as required Handle the new elements carefully do not use if the sealing surfaces are bent or damaged 5 Check all parts for wear cracks or damage Replace any damaged components 6 Install the new inner element followed by the outer element Slide each fully into place in the air cleaner housing Figure 4 12 Heavy Duty Air Cleaner 7 Reinstall the end cap so the dust ejector valve is down and secure with the two retaining clip
185. her rocker arm 4 Useaspanner wrench or rocker arm lifting tool see Section 2 to lift the rocker arms and position the push rods underneath See Figure 11 47 11 13 Section 11 Reassembly 5 Repeat the above steps for the remaining cylinder Do not interchange parts from the cylinder heads nch to Lift Rocker Figure 11 47 Using Spanner Wre Arm Over Push Rod 6 Rotate the crankshaft to check for free operation of the valve train Check the clearance between the valve spring coils at full lift Minimum allowable clearance is 0 25 mm 0 010 in Check Assembly Important Rotate the crankshaft a minimum of two revolutions to check longblock assembly and overall proper operation Install Spark Plugs 1 Use new Champion or equivalent spark plugs 2 Setthe gap at 0 76 mm 0 030 in for all except natural gas with CD fixed ignition or 0 51 mm 0 020 in for natural gas with CD fixed ignition 3 Install new plugs and torque to 24 4 29 8 N m 18 22 ft Ib See Figure 11 48 Figure 11 48 Installing Spark Plugs 11 14 Install Ignition Modules Rotate the flywheel to position the magnet away from the ignition module bosses 1 Figure 11 49 Installing Ignition Module pa On engines equipped with SMART SPARK both modules are installed the same way with the two tabs out See Figure 11 55 On engines are not equipped with SMART SPARK the modules are installed with
186. hes nicks or burrs can result in leaks See Service Bulletin 252 for further information Refer to A Guide to Engine Rebuilding TP 2150 A for additional information Measurement Guide TP 2159 B and Engine Inspection Data Record TP 2435 are also available use these to record inspection results Automatic Compression Release ACR Some engines are equipped with the optional Automatic Compression Release ACR mechanism The ACR lowers compression at cranking speeds to make starting easier Operation The ACR mechanism consists of a flyweight spring and pivoting control pin assembly attached to the gear on the camshaft At cranking speeds 700 RPM or lower the control pin protrudes above the exhaust cam lobe This pushes the exhaust valve off its seat during the first part of the compression stroke The reduced compression results in an effective compression ratio of about 2 1 during cranking After starting engine speed increases to over 700 RPM and centrifugal force overcomes the force of the flyweight spring The flyweight moves outward pulling the arm of the control pin so it pivots into the run position The control pin no longer has any effect on the exhaust valve and the engine operates at full power When the engine is stopped the spring returns the flyweight lever and control pin assembly to the compression release position ready for the next start Camshaft Inspection and Service Check the lobes of the
187. hrottle opening 3 Engine runs lean indicated by misfiring loss of speed and power governor hunting or excessive throttle opening 4 Fuel leaks from carburetor Aa b e d 5 4 Low idle fuel mixture some models speed improperly adjusted Adjust the low idle speed tab then adjust the low idle fuel needle Clogged air cleaner Clean or replace Choke partially closed during operation Check the choke lever linkage to ensure choke is operating properly Low idle fuel mixture is improperly adjusted Adjust low idle fuel needle some models Float level is set too high Separate carburetor air horn from carburetor body adjust float to specification Dirt under the fuel inlet needle Remove needle clean needle and seat and blow with compressed air Bowl vent or air bleeds plugged Remove low idle fuel adjusting needle Clean vent ports and air bleeds Blow out all passages with compressed air Leaky cracked or damaged float Submerge float to check for leaks Low idle fuel mixture is improperly adjusted Adjust low idle fuel needle some models Float level is set too low Separate carburetor air horn from carburetor body adjust float specification Idle holes plugged dirt in fuel delivery channels Remove low idle fuel adjusting needle Clean main fuel jet and all passages blow out with compressed air Float level set too high See Remedy 2d Dirt under fuel
188. if any teeth are missing Inspect the governor weights They should move freely in the governor gear 10 11 Section 10 Inspection and Reconditioning Disassembly Reassembly The governor gear must be replaced once it is 1 Install the locking tab thrust washer on the removed from the closure plate governor gear shaft with the tab down NOTE The governor gear is held onto the shaft by 2 Position the regulating pin within the governor small molded tabs in the gear When the gear gear flyweight assembly and slide both onto the is removed from the shaft these tabs are governor shaft destroyed and the gear must be replaced Therefore remove the gear only if absolutely Oil Pump Assembly necessary Disassembly 1 Remove the regulating pin and governor gear 1 Remove the two hex flange screws assembly See Figure 10 13 2 Remove the oil pump assembly from the closure plate 3 Remove the oil pump rotor 4 Remove the oil pickup by unhooking the locking clip and pulling it free from the oil pump body 5 Ifthe relief valve is like that shown in Figure 10 15 drive out the pin to remove the oil pressure relief valve piston and spring Refer to the following inspection and reassembly procedures If the relief valve is a one piece style staked to the oil pump housing See Figure 10 16 removal should not be attempted nor is internal servicing possible If a problem with the relief valve is encountered the oil pump shoul
189. igures 5 4 and 5 5 Depending on model and application engines may also be equipped with a Governed Idle System If equipped with a Governed Idle System refer to Models with Governed Idle System when performing any carburetor adjustment as an additional step to the listed adjustment procedure s is required Low Idle Speed Adjustment t Fe i Jj d 1 V E i Y ya Low Idle Fuel Adjusting Needle Veet SSR L ly c2 b m Figure 5 4 Pre Compliance Carburetor with Low Idle Adjustment 5 6 l Fuel Shut Off Solenoid Main Jet Location Figure 5 5 Certified Compliance Carburetor NOTE Carburetor adjustments should be made only after the engine has warmed up Adjusting Low Idle Speed and Fuel Some Models To adjust the carburetor idle speed see Figure 5 4 and follow these steps 1 With the engine stopped turn the low idle fuel adjusting needle in clockwise until it bottoms lightly NOTE The tip of the idle fuel adjusting needle is tapered to critical dimensions Damage to the needle and the seat in the carburetor body will result if the needle is forced 2 Now turn the adjusting needle out counterclockwise 1 1 2 turns 3 Start the engine and run at half throttle for 5 to 10 minutes to warm up The engine must be warm before making final settings Check that the throttle and choke plates can fully open NOTE The carburetor has a self relieving
190. ine ground back toward the sensor watching for a 5B 12 voltage reading reappears at some point check for a problem rust corrosion loose joint or connection between that point and the previous checkpoint For example if the reading is too low at points on the crankcase but correct voltage is indicated when the black lead is touched to the skin of the muffler the flange joints at the exhaust ports become suspect With sensor still hot minimum of 400 C 752 F switch meter to the Rx1K or Rx2K scale and check the resistance between the sensor lead and sensor case It should be less than 2 0 KQ a If the resistance is less than 2 0 KQ go to Step 4 b If the resistance is greater than 2 0 KQ the oxygen sensor is bad replace it Allow the sensor to cool less than 60 C 140 F and retest the resistance with the meter set on the Rx1M scale With sensor cool the resistance should be greater than 1 0 MQ a If the resistance is greater than 1 0 MQ go to Step 5 b If the resistance is less than 1 0 MQ the sensor is bad replace it With the oxygen sensor disconnected and engine not running disconnect the main harness connector from the ECU and set the meter to the Rx1 scale Check the circuit continuity as follows 35 Pin MA 1 7 Metal Cased ECU Check for continuity from pin 9 of the ECU connector see page 5B 28 to the shell of the oxygen sensor and from pin 10 to the sensor connector terminal
191. ine alcohol blends including E20 and E85 are not to be used and not approved Any failures resulting from use of these fuels will not be warranted Gasoline Ether blends Methyl Tertiary Butyl Ether MTBE and unleaded gasoline blends up to a maximum of 1576 MTBE by volume are approved as a fuel for Kohler engines Other gasoline ether blends are not approved EFI Fuel System Components General The Electronic Fuel Injection EFI system is a complete engine fuel and ignition management design The system includes the following principal components e Fuel Pump Fuel Filter Fuel Rail Fuel Line s Fuel Pressure Regulator Fuel Injectors Throttle Body Intake Manifold Engine Control Unit ECU Ignition Coils Engine Oil Temperature Sensor Throttle Position Sensor TPS Speed Sensor Oxygen Sensor Wire Harness Assembly amp Affiliated Wiring Malfunction Indicator Light MIL Operation The EFI system is designed to provide peak engine performance with optimum fuel efficiency and lowest possible emissions The ignition and injection functions are electronically controlled monitored and continually corrected during operation to maintain the theoretical ideal or stoichiometric air fuel ratio of 14 7 1 The central component of the system is the Motronic Engine Control Unit ECU which manages system operation determining the best combination of fuel mixture and ignition timing for the current operating conditions An elec
192. ine on the screen Accelerate to full throttle and watch for movement of the line on the screen relative to the line on the blower housing If both cylinders had good spark repeat the test on the other cylinder See Figure 8 19 Figure 8 19 Check for Timing Advance Section 8 Electrical System and Components a Iftheline on the screen moved away from the line on the blower housing during acceleration the DSAI ignition module for the cylinder being tested is working properly If it didn t move away go to Test 4 b Ifyou were able to check timing on both cylinders the lines you made on the blower housing should be 90 apart If not go to Test 4 Test 4 Test the Ignition Modules and Connections 1 Remove the blower housing from the engine Inspect the wiring for any damage cuts bad crimps loose terminals or broken wires Check that connections are oriented properly on terminals of modules 2 Disconnect the leads from the ignition module s and clean all of the terminals male and female with aerosol electrical contact cleaner to remove any old dielectric compound dark residue dirt or contamination Disconnect the spark plug leads from the spark plugs 3 Using a multi meter check that a proper ground is established between the ground black lead of the DSAI module closest to spark plug lead and a known good ground location on the engine 4 Turn the key switch to the ON position and check for 12 volts at
193. ing tested individually a If both cylinders have good spark but the engine runs poorly install new spark plugs gapped at 0 76 mm 0 030 in and retest engine performance If problem persists go to Test 3 Figure 8 9 3 Runthe engine at idle and use the timing light beam to locate the line on the screen Draw a line on the blower housing adjacent to the line on the screen Accelerate to full throttle and watch for movement of the line on the screen relative to the line on the blower housing If both cylinders had good spark repeat the test on the other cylinder b If one cylinder had good spark but the other cylinder had no spark or intermittent spark go to Test 3 c If there was no spark or intermittent spark on both cylinders go to Test 4 a If the line on the screen moved away from the line on the blower housing during acceleration the SAM is working properly If it didn t move away go to Test 5 8 9 Section 8 Electrical System and Components b If you were able to check timing on both cylinders the lines you made on the blower housing should be 90 apart If they re not go to Test 4 Test 4 Test the ignition modules and connections 1 8 10 Remove the blower housing from the engine Inspect the wiring for any damage cuts bad crimps loose terminals or broken wires Disconnect the leads from the ignition module s and clean all of the terminals male and female with aerosol electric
194. ing on cause If performance is pretty good the problem is probably with the oxygen sensor wiring or connectors If the engine is still running rich laboring short on power or lean popping or misfiring the fuel mixtureis suspect probably incorrect TPS initialization or low fuel pressure Possible Causes 1 TPS Initialization Incorrect a Lean condition check oxygen sensor signal with VOA and see Oxygen Sensor section 2 Engine Wiring Harness Related a Pin circuit wiring or connectors Pin 10 for 35 Pin MA 1 7 Metal Cased ECU Pin 11 for 24 Pin MSE 1 0 Plastic Cased ECU Pin 20 for 32 Pin MSE 1 1 Plastic Cased ECU 3 Low Fuel Pressure 4 Oxygen Sensor Related a Sensor connector or wiring problem b Exhaust leak c Poor ground path to engine sensor is case grounded 5 Poor system ground from ECU to engine causing rich running while indicating lean 5B 39 Section 5B EFI Fuel System Code 32 Source Oxygen Sensor Explanation No change in the sensor output signal Expected Engine Response Open loop operation only may cause a drop in system performance and fuel efficiency Possible Causes 1 Engine Wiring Harness Related a Pin circuit wiring or connectors Pin 10 for 35 Pin MA 1 7 Metal Cased ECU Pin 11 for 24 Pin MSE 1 0 Plastic Cased ECU Pin 20 for 32 Pin MSE 1 1 Plastic Cased ECU 2 Oxygen Sensor Related a Sensor connector
195. ing or replacement Fuel Line Figure 5B 34 High Pressure Fuel Line General Special low permeation high pressure fuel line with an SAE30 R9 rating is required for safe and reliable operation due to the higher operating pressure of the EFI system If hose replacement is necessary order Fuel Line Service Kit Part No 25 111 37 S containing 60 of high pressure hose and 10 Oetiker clamps or use only the type specified Special Oetiker clamps Kohler Part No 24 237 05 S are used on all fuel line connections to prevent tampering and safety hazards with the high fuel pressure The old clamp must be cut to open a connection so replacement is necessary each time Oetiker Clamp Pliers part of EFI Service Kit see Section 2 is used to crimp the replacement clamps A CAUTION Fuel lines between the fuel pump and fuel rail must be made from SAE 30 R9 fuel line Standard fuel line SAE 30 R7 may only be used between the fuel tank and pump 5 16 ID and for the return line from the pressure regulator to the tank 1 4 ID All high pressure fuel line connections must be secured with Oetiker Clamps Kohler Part No 24 237 05 S installed crimped with the corresponding pliers Throttle Body Intake Manifold Assembly gLow Idle Speed Adjusting Screw Comer Figure 5B 35 Upper Intake Manifold General The EFI engines have no carburetor so the throttle function regulate incoming combustion airflow is incorporated in
196. ircuits 84 85 and J1 2 as the key is swept from the start to the run position to prevent ECU reset during starting The voltage on circuits 84 85 J1 2 and J1 1 must remain within 0 2 V of each other regardless of system current draw to prevent differences between actuator voltages circuits 65 66 45 and 87 and system voltage J1 1 If the ignition switch controls a powered circuit i e lights horn it is recommended that a relay be used to control the power To prevent signal errors load circuits i e horn lights shall not be powered from EFI engine or chassis wire harness A resistive spark plug with either a resistive spark plug wire or boot must be used to prevent electrical system noise It is recommended that the ECU housing is mounted with the wire harness down to facilitate proper drainage away from the electrical connector When not in operation the battery must maintain a minimum system voltage of 7V with a current draw of 2 mA to maintain the adaptive memory During starting the system voltage must be 7V minimum for the ECU operation during cranking Unless otherwise specified all wires are 18AWG Speed sensor wires pins 9 and 10 are to be a twisted pair with 1 twist inch minimum Malfunction indicator lamp MIL can be a 12V 0 25A incandescent lamp Optionally a 20 mA LED can be used This requires a resistor of approximately 600 ohms wired in parallel Normal operating voltage is to 16V dc 9Vdc with a cold
197. ive cup Hold the handle in this position and tighten the screws securely Rope Replacement The rope can be replaced without complete starter disassembly 1 Remove the starter from the blower housing 2 Pull the rope out approximately 12 in and tiea temporary slip knot in it to keep it from retracting into the starter See Figure 7 2 Hex s Starter Housing Flange Screws Handle with Rope Retainer Pulley m iid Springs 5 Brake Washer f C PANIS BS Brake Spring Plain Washer Center Screw gu Figure 7 1 Retractable Starter Exploded View Pawl Retainer Drive Cup 7 1 Section 7 Retractable Starter Slipknot Rope Retainer Figure 7 2 Removing Starter Handle 3 Remove the rope retainer from inside the starter handle Untie the single knot and remove the rope retainer and handle 4 Hold the pulley firmly and untie the slipknot Allow the pulley to rotate slowly as the spring tension is released 5 When all spring tension on the starter pulley is released remove the rope from the pulley 6 Tiea single knot in one end of the new rope 7 Rotate the pulley counterclockwise when viewed from pawl side of pulley until the spring is tight approximately 6 full turns of pulley 8 Rotate the pulley clockwise until the rope hole in the pulley is aligned with the rope guide bushing of the starter housing NOTE Do not allow the pulley spring to unwind Enlist the aid of a helper if
198. jury since broken fragments could be thrown from the engine Always observe and use the following precautions and procedures when installing the flywheel NOTE Before installing the flywheel make sure the crankshaft taper and the flywheel hub are clean dry and completely free of any lubricants The presence of lubricants can cause the flywheel to be over stressed and damaged when the hex flange screw is torqued to specifications Figure 11 23 Torquing Stator Screws 4 Route the stator leads in the crankcase channel then install the backing plates and the stator wire bracket if used Secure using the four hex flange screws See Figures 11 24 and 11 25 Torque the screws to 7 3 N m 65 in Ib Figure 11 24 Route Stator Leads in Groove Figure 11 27 Clean and Dry Flywheel Hub Figure 11 25 Installing Backing Plates and Stator Wire Bracket Section 11 Reassembly Install Flywheel Fan 1 Install the fan onto the flywheel using the four hex flange screws NOTE Position the ears located at rear perimeter of the fan in the recesses of the flywheel See Figure 11 30 Figure 11 28 Carefully Align Keyway to Key NOTE Make sure the flywheel key is installed properly in the keyway The flywheel can become cracked or damaged if the key is not properly installed 1 Install the woodruft key into the keyway of the crankshaft Make sure that the key is properly Figure 11 30 Installing Fan on Fl
199. ke will occur until closed loop operation is initiated A stumble or misfire on hard acceleration and or erratic operation may be exhibited Possible Causes 1 TPS Sensor Related a b C Sensor connector or wiring Sensor output affected or disrupted by dirt grease oil wear or breather tube position must be to side opposite the TPS Sensor loose on throttle body manifold 2 Throttle Body Related a Throttle shaft or bearings worn damaged 3 Engine Wiring Harness Related 35 Pin MA 1 7 Metal Cased ECU a b Pin circuits 12 25 and or 27 damaged wiring or connectors Pin circuits 12 25 and or 27 routed near noisy electrical signal coils alternator Intermittent 5 volt source from ECU pin circuit 25 3 Engine Wiring Harness Related 24 Pin MSE 1 0 Plastic Cased ECU a b Pin circuits 4 8 and or 14 damaged wiring connectors Pin circuits 4 8 and or 14 routed near noisy electrical signal coils alternator Intermittent 5 volt source from ECU pin circuit 14 3 Engine Wiring Harness Related 32 Pin MSE 1 1 Plastic Cased ECU a Pin circuits 4 8 and or 18 damaged wiring connectors b Pin circuits 4 8 and or 18 routed near noisy electrical signal coils alternator c Intermittent 5 volt source from ECU pin circuit 18 4 ECU Harness Related a ECU to harness connection problem Code 23 Source ECU Explanation ECU is una
200. key switch on e Always disconnect negative battery cable lead before charging battery and also unplug harness from ECU before performing any welding on equipment Electrical Components Electronic Control Unit ECU Boscy T MEAE FA E Il l I EN Figure 5B 1 35 Pin MA 1 7 Metal Cased ECU Figure 5B 2 24 Pin MSE 1 0 Plastic Cased ECU Section 5B EFI Fuel System The ECU continually performs a diagnostic check of itself each of the sensors and the system performance If a fault is detected the ECU turns on the Malfunction Indicator Light MIL on the equipment control panel stores the fault code in its fault memory and goes into a default operating mode Depending on the significance or severity of the fault normal operation may continue or limp home operation slowed speed richer running may be initiated A technician can access the stored fault code using a blink code diagnosis flashed out through the MIL An optional computer software diagnostic program is also available see Section 2 Figure 5B 3 32 Pin MSE 1 1 Plastic Cased The ECU requires a minimum of 7 0 volts to operate ECU The adaptive memory in the ECU is operational the moment the battery cables are connected however Three different styles of ECU s have been utilized the adapted values are lost if the battery becomes 5B in EFI production The first style 1S easily identified disconnected for any reason The E
201. l Figure 11 37 Assemble Cylinder Heads Prior to installation lubricate all components with engine oil paying particular attention to the lip of the valve stem seal valve stems and valve guides Install the following items in the order listed below using a valve spring compressor See Figures 11 38 and 11 39 Intake and exhaust valves Valve spring caps Valve springs Valve spring retainers Valve spring keepers Section 11 Reassembly Figure 11 39 Installing Valves with Valve Spring Compressor Install Cylinder Heads NOTE Cylinder heads must be attached with the original type of mounting hardware using either hex flange screws or mounting n studs with nuts and washers The heads are machined differently for studs than for screws so the fastening method cannot be altered unless the heads are being replaced Do not intermix the components 1 Check to make sure there are no nicks or burrs on the sealing surfaces of the cylinder head or the crankcase 11 11 Section 11 Reassembly Heads secured with hex flange screws 2 Install a new cylinder head gasket with printing up Figure 11 42 Cylinder Head Fastener Torque Sequence Heads secured with mounting studs nuts and washers NOTES Matcbtbesumbersenmbossedomths 1 Ifallof the studs were left intact go to Step 6 If cylinder heads and crankcase See Figure any studs were disturbed or removed install new 11 36 studs as described in Step 3
202. l can be made out of an old junk flywheel ring gear as shown in Figure 2 1 and 3 Find a 1 in long capscrew with the correct used in place of a strap wrench thread size to match the threads in the connecting rod 1 Using an abrasive cut off wheel cut out a six tooth segment of the ring gear as shown 4 Usea flat washer with the correct I D to slip on the capscrew and approximately 1 O D Kohler 2 Grind off any burrs or sharp edges Part No 12 468 05 5 Assemble the capscrew and washer to the joint surface of the rod as 3 Invert the segment and place it between the shown in Figure 2 2 ignition bosses on the crankcase so that the tool teeth engage the flywheel ring gear teeth The bosses will lock the tool and flywheel in position for loosening tightening or removing with a puller Figure 2 2 Rocker Arm Crankshaft Tool Figure 2 1 Flywheel Holding Tool Rocker Arm Crankshaft Tool A spanner wrench to lift the rocker arms or turn the crankshaft may be made out of an old junk connecting rod 1 Find a used connecting rod from a 10 HP or larger engine Remove and discard the rod cap 2 4 Section 3 Troubleshooting Troubleshooting Guide When troubles occur be sure to check the simple causes which at first may seem too obvious to be considered For example a starting problem could be caused by an empty fuel tank Some general common causes of engine troubles are listed below Use these to locate th
203. l the breather hose in the hole in the bracket 5 Install the air cleaner components as described in Section 4 Heavy Duty Air Cleaner 1 Connect the breather hose to breather cover and fitting on adapter elbow Route the fuel line adjacent to fuel solenoid and secure to the carburetor inlet with a clamp See Figure 11 96 4 4 D i j E j s i a a wm M BE a TE o E P LES hrs dO d Figure 11 93 Fuel Inlet Line Detail 11 28 Section 11 Reassembly Carburetor Fuel Line Figure 11 96 Breather Hose and Fuel Line Details Figure 11 98 Assembled Heavy Duty Air Cleaner Two Barrel Carburetor 2 Align the air cleaner mounting bracket with the valve cover mounting holes and start the screws Install Muffler On two barrel carburetor models start the two 1 Install the port liners if equipped Install the mounting screws into the top of intake manifold muffler and attaching hardware to the muffler See Figure 11 97 bracket Torque screws to 9 9 N m 88 in Ib 2 Install the hex flange nuts to the exhaust studs Torque hex flange nuts to 24 4 N m 216 in Ib Install Oil Cooler 1 Reinstall the oil cooler on the engine if equipped Install a new gasket between the cooler and the closure plate Torque nipple adapter to 27 N m 20 ft Ib See Figures 11 99 and 11 100 d a2 j f i i i A Figure 11 97 Mounted Air Cleaner Bracket Two Barrel Carburetor
204. linkage clamp bracket should be positioned as shown in Figure 5A 13 on the idle speed clamp bracket side of the throttle shaft High Speed Stop Collar Figure 5A 11 Full Throttle Position Throttle Linkage Clamp Bracket Figure 5A 13 Throttle Linkage Clamp Bracket Position 5A 7 Section 5A LPG Fuel Systems 2s Figu Manually move the governor lever with the throttle linkage connected toward the carburetor as far as it will go Hold it in this position Looking down the throat of the carburetor check that the throttle plate is in the full throttle position and that the head of the high speed collar stop screw is in contact with the carburetor boss If not loosen the carburetor mounting screws and reposition the carburetor slightly Torque the carburetor mounting screws to 9 9 N m 88 in Ib NOTE If additional adjustment is required loosen the throttle linkage clamp bracket mounting screw set the throttle shaft to the full throttle position against the head of the stop screw and retighten the clamp mounting screw securely See Figure 5A 14 re 5A 14 Tightening Throttle Linkage Clamp Bracket Nikki Carburetor 1 5A 8 Reinstall the rear plug with a new sealing washer Tighten the plug securely Reinstall fuel transfer chamber cover with a new gasket Secure with the three screws Install new carburetor mounting gasket on manifold studs followed by the carburetor and new air
205. ll quantities and store in clean approved containers A container with a capacity of 2 gallons or less with a pouring spout is recommended Such a container is easier to handle and helps eliminate spillage during refueling e Do not use gasoline left over from the previous season to minimize gum deposits in your fuel system and to ensure easy starting e Do not add oil to the gasoline e Do not overfill the fuel tank Leave room for the fuel to expand Fuel Type For best results use only clean fresh unleaded gasoline with a pump sticker octane rating of 87 R M 2 or higher In countries using the Research Octane Number RON it should be 90 octane minimum Leaded gasoline is not recommended and must not be used on EFI engines or on other models where exhaust emissions are regulated Gasoline Alcohol blends Gasohol up to 10 ethyl alcohol 90 unleaded gasoline by volume is approved as a fuel for Kohler engines Other gasoline alcohol blends including E20 and E85 are not to be used and not approved Any failures resulting from use of these fuels will not be warranted 5 1 Section 5 Fuel System and Governor Gasoline Ether blends Methyl Tertiary Butyl Ether MTBE and unleaded gasoline blends up to a maximum of 15 MTBE by volume are approved as a fuel for Kohler engines Other gasoline ether blends are not approved Fuel Filter Most engines are equipped with an in line fuel filter Periodically inspect the filte
206. ll the dipstick See Figure 11 104 Section 11 Reassembly Prepare the Engine for Operation The engine is now completely reassembled Before starting or operating the engine be sure to do the following 1 Make sure all hardware is tightened securely 2 Make sure the oil drain plugs oil sentry pressure switch and a new oil filter are installed 3 Fill the crankcase with the correct amount weight and type of oil Refer to oil recommendations and procedures in the Safety and General Information and Lubrication Figure 11 104 Reinstall the Dipstick in Tube System sections 6 Make sure the O Ring is in place then reinstall the 4 Adjust the carburetor idle fuel needle or idle oil fill cap on the valve cover See Figure 11 105 speed adjusting screw as necessary Refer to Section 5 the Fuel System and Governor Testing the Engine It is recommended that the engine be operated on a test stand or bench prior to installation in the piece of equipment 1 Set the engine up on a test stand Install an oil pressure gauge Start the engine and check to be certain that oil pressure 20 psi or more is present Run the engine at idle for 2 3 minutes then 5 6 minutes more between idle and midrange Adjust the carburetor mixture settings as necessary as available Figure 11 105 Reinstalling Oil Fill Cap Some Models 2 Adjust the idle speed screw and high speed stop as necessary Make sure the maximum
207. ll traces of any cleaner are removed before the engine is assembled and placed into operation Even small amounts of these cleaners can quickly break down the lubricating properties of engine oil Check the closure plate crankcase cylinder heads and valve covers to be certain that all old sealing material has been removed Use gasket remover lacquer thinner or paint remover to remove any remaining traces Clean the surfaces with isopropyl alcohol acetone lacquer thinner or electrical contact cleaner Typical Reassembly Sequence The following sequence is suggested for complete engine reassembly This procedure assumes that all components are new or have been reconditioned and all component subassembly work has been completed The sequence may vary to accommodate options or special equipment Detailed procedures follow Install flywheel end oil seal Install governor cross shaft Install crankshaft Install connecting rods with pistons and rings Install camshaft Install closure plate assembly Install stator and backing plates Install flywheel 9 Install fan and grass screen 10 Install hydraulic lifters 11 Install cylinder heads 12 Install push rods and rocker arms 13 Install ignition modules per pu PI I 14 15 16 17 18 19 20 21 22 23 24 25 26 zs 28 Install intake manifold Install breather cover and inner baffles Install blower housing and outer baftles Install electric starte
208. lly seated that are worn or damaged 3 Install the low idle adjusting needle and spring e Inspect the carburetor body for cracks holes and other wear or damage 4 Assemble the upper body onto the lower 5 carburetor body using the four screws Torque e Inspect the float for cracks holes and missing the screws to 1 7 N m 15 in Ib or damaged float tabs Check the float hinge and shaft for wear or damage 5 Install the carburetor on the engine following the procedures in Section 11 Reassembly e Inspect the fuel inlet needle and seat for wear or damage e Inspect the tip of the low idle fuel adjusting needle for wear or grooves e The choke plate is spring loaded Check to make sure it moves freely on the shaft NOTE The choke and throttle plate assemblies are staked and matched to the shafts at the factory They are not serviceable items Always use new gaskets when servicing or reinstalling carburetors Repair kits are available which include new gaskets and other components These kits are described on the next page 5 9 Section 5 Fuel System and Governor Carburetor Upper Body Choke Self relieving Choke Body Gasket Formed Rubber Slow Speed Jet Inlet Needle Valve Clip Float Pin Float Assembly Kit Carburetor Lower Body Throttle Main Jet Idle Fuel Adjusting Needle some models Solenoid Seat Fuel Shut off Solenoid Kit Idle Speed Adjusting Screw Jet Accelerator Pump
209. lt codes and run the engine to check if any fault codes reappear To Replace Oxygen Sensor 1 Disconnect the oxygen sensor connector from wiring harness Loosen and remove the oxygen sensor from the exhaust manifold muffler assembly Apply anti seize compound sparingly to threads of new oxygen sensor if none already exists DO NOT get any on the tip as it will contaminate the sensor Install sensor and torque to 50 60 N m 37 44 ft Ib Reconnect the lead to wiring harness connector Make sure it can not contact hot surfaces moving parts etc Test run the engine Section 5B EFI Fuel System Electrical Relay Figure 5B 13 Electrical Relay General The electrical relay is used to supply power to the injectors coils and fuel pump When the key switch is turned on and all safety switch requirements met the relay provides 12 volts to the fuel pump circuit injectors and ignition coils The fuel pump circuit is continuously grounded so the pump is immediately activated and pressurizes the system Activation of the ignition coils and injectors is controlled by the ECU which grounds their respective circuits at the proper times Service A malfunctioning relay can result in starting or operating difficulties The relay and related wiring can be tested as follows 1 Disconnect the relay connector plug from the relay Connect black lead of VOA meter to a chassis ground location Connect red lead t
210. ly Remove the four screws and carefully separate the air horn assembly from the carburetor body Loosen the screw securing the float assembly to the air horn and remove the float float shaft and fuel inlet needle Remove the slow jet from the carburetor body NOTE The main jet is a fixed jet and can be removed if required Fixed jets for high altitude are available Remove the black cap on the end of the choke shaft only if it is necessary to inspect and clean the shaft spring Remove the low idle speed adjusting screw and spring from the carburetor body Section 5 Fuel System and Governor 7 In order to clean the off idle vent ports and Reassembly bowl vent thoroughly use a good carburetor Reassemble the carburetor using the following steps solvent like Gumout Blow clean compressed See Figure 5 10 air through the idle adjusting needle hole Be careful to use a suitable shop rag to prevent 1 Assemble the fuel inlet needle to the float tab debris from hitting someone Install the float float shaft and inlet needle to the air horn Tighten the screw Check float height 8 Remove the preformed rubber gasket only if it using the procedure found previously in the is to be replaced If it is removed for any reason Adjustments subsection replace it 2 Install the slow jet with the stepped end toward Inspection Repair the bottom of the carburetor Make sure jet is Carefully inspect all components and replace those fu
211. m 300 in Ib Head Bolt LOGS qm TWO SU DEB outesaideimeSansbaceihtvdisesetis din sU raed ERU EC ONE first to 22 6 N m 200 in Ib finally to 41 8 N m 370 in Ib Max LOB IN OS occiduo dia itu a GUUER ONE NIoRI ER RaU MIN ERN a bnc OE eai 0 076 mm 0 003 in Rocker pm oC KEV TOTO HO usus dutrdiostitostastn aide T ani I an 11 3 N m 100 in Ib Fan Flywheel Lon astenner TORO aieri inaina eorr nae tnu Er naaa iiaiai UM ERU 9 9 N m 88 in Ib Flywheel Retaining Screw J Or Qe unisce retta pesar iiri n era aani 66 4 N m 49 ft Ib Governor Governor Cross Shaft to Crankcase Running Clearance DEED p a E E eia dS Deu Ub duet AE E RR MD PEN 0 013 0 075 mm 0 0005 0 0030 in B qnt SDN onse INIM EEA AI E NHIEU 0 025 0 126 mm 0 0009 0 0049 in Governor Cross Shaft O D 6 mm Shaft iU 5 975 6 012 mm 0 2352 0 2367 in Max Wear EEG duneciesdesstidis on E E tique esee E du cpm EUR ER dUE 5 962 mm 0 2347 in 8 mm Shaft IN c 7 949 8 000 mm 0 3129 0 3149 in INI VC oi TS ENDE oegonsenicesq einst QeV EE E E 7 936 mm 0 3124 in Governor Gear Shaft to Governor Gear Running Clearance 0 015 0 140 mm 0 0006 0 0055 in Governor Gear Shaft O D hU m A 5 990 6 000 mm 0 2358 0 2362 in IUe E a Suidae dades uote Pad sate sesso E acer vU DRM esu T 5 977 mm 0 2353 in COV ne 6 r ETE NA TOT
212. m the SAM black on singles green on twins to the grounding screw Connect the black voltmeter lead to the eyelet terminal of the ground lead or the ground screw bolt Section 8 Electrical System and Components Check the voltage with the key switch in both the START and RUN positions A minimum of 7 25 volts must be present a If correct voltage is not measured connect black voltmeter lead directly to the negative post of the battery and test voltage again in both key positions If correct voltage is now indicated check the ground circuit connections If the ground screw bolt or any other fasteners in the ground circuit are black oxide coated replace them with zinc plated silver colored fasteners b If correct voltage is still not indicated check the harness connector terminal for a good connection and crimp to the lead Then trace the power source circuit back through the harness key switch etc looking for any poor connections or faulty circuits 2 Disconnect all of the SAM leads isolating it from the engine Test the SAM according to style with tester 25 761 21 S tests ASAM style modules only or tester 25 761 40 S tests both ASAM and DSAM style modules Use the test instructions following or those provided with the tester 3 Reattach the SAM leads veritying a snug fit at the ignition module terminals If any connections do not feel snug disconnect the lead lightly pinch the female ter
213. m spacer and the checking tool Camshaft end play should be 0 076 0 127 mm 0 003 0 005 in 4 Ifthe camshaft end play is not within the specified range remove the checking tool and replace the shim as necessary Several color coded shims are available White 20 69215 0 73025 mm 0 02725 0 02875 in Blue 0 74295 0 78105 mm 0 02925 0 03075 in Red 0 79375 0 83185 mm 0 03125 0 03275 in Yellow 0 84455 0 88265 mm 0 03325 0 03475 in Green 0 89535 0 99345 mm 0 03525 0 03675 in Gray 0 94615 0 98425 mm 0 03725 0 03875 in Black 0 99695 1 03505 mm 0 03925 0 04075 in 5 i ciata m HT Play Figure 11 15 Change Shim to Obtain Correct End Section 11 Reassembly 5 Reinstall the end play checking tool and recheck the end play Oil Pump Assembly The oil pump is mounted inside the closure plate If service was required and the oil pump was removed refer to the assembly procedures under Oil Pump Assembly in Section 10 Governor Gear Assembly The governor gear assembly is located inside the closure plate If service was required and the governor was removed refer to the assembly procedures under Governor Gear Assembly in Section 10 Thrust Bearing Washer and Shim Some specifications use a needle type thrust bearing thrust washer and shim spacer to control the end play of the crankshaft See Figure 11 16 If these items are noted during disassembly make sure they are reinstalled in the se
214. minal with a pliers and recheck the fit 4 Sealthe base of the ignition module connections with GE Novaguard G661 see Section 2 Fel Pro Lubri Sel dielectric compound The beads should overlap between the two connections to form a solid bridge of compound Do not put any compound inside the connectors t The 24 584 15 S ignition modules have a separator barrier between the terminals On these modules seal the base of the terminal if any portion of it is exposed but it is not necessary to have overlapping beads of sealant between the connections 5 Test for spark Test 2 to be sure the system is working before you reinstall the blower housing If there is still a spark problem on one side replace that ignition module and recheck spark 8 11 Section 8 Electrical System and Components To Test Using 25 761 21 S Tester ASAM only Test Procedure NOTE The SAM must be at room temperature when tested Disconnect all of the SAM leads isolating it from the main wiring harness and the ignition module s Testing may be performed with the module mounted or loose The figures show the part removed from the engine for clarity Figure 8 10 1 Connect the tester to the SAM as follows Attach A The yellow tester lead to the long yellow module lead B The brown tester lead to the long brown module lead C The red tester lead to the red module lead D The green tester lead to the green module lead Cau
215. mmutator end cap Service may be necessary more frequently under dusty or dirty conditions 5 Remove the insulator and the brush springs from the brush spring holder Starter Reassembly 1 Insert the rear stop collar on the armature shaft 6 Remove the armature from the frame 2 Place the retainer in the groove on the armature 7 Remove the drive lever and the armature from shaft the drive end cap NOTE Always use a new retainer Tighten the NOTE When removing the lever and the retainer in the groove to secure armature be careful not to lose the thrust washer 3 Fitthe front stop collar over the shaft and bring the front and the rear stop collars together over 8 The stop collar consists of two similar pieces the retainer Using two pairs of pliers apply even held in place by being snapped over a retainer force to the two collars until they snap over the The retainer is held in place by a groove in the retainer and nest into one another armature shaft To remove the stop collar the two pieces must be pried off the retainer 4 Reassemble the remaining components of the starter in reverse order from disassembly 9 When the stop collars are removed the retainer 8 can be removed from the armature shaft Do not Delco Remy Starters reuse the retainer Brush Replacement The brushes in the starter are part of the starter frame Brush kit Kohler Part No 52 221 01 S contains four replacement brushes and springs If replacement is ne
216. mp fuel pressure c Combustion air air cleaner dirty restricted intake leak throttle bores Base engine problem rings valves Exhaust system leak Fuel in the crankcase oil Blocked or restricted fuel return circuit to tank Qo moo 6 ECU Harness Related a ECU to harness connection problem Code 34 Source Oxygen Sensor Fuel System Components Explanation Long term fuel adaptation control is at the upper or lower limit Expected Engine Response System operates closed loop No appreciable performance loss as long as the temporary adaptation can provide sufficient compensation Possible Causes 1 Ln Sensor Related Sensor connector or wiring problem Sensor contaminated or damaged Exhaust leak Poor ground path Pin circuit wiring or connectors Pin 10 for 35 Pin MA 1 7 Metal Cased ECU Pin 11 for 24 Pin MSE 1 0 Plastic Cased ECU Pin 20 for 32 Pin MSE 1 1 Plastic Cased ECU oo op 2 TPS Sensor Related a Throttle plate position incorrect during Initialization procedure b TPS problem or malfunction 3 Engine Wiring Harness Related a Difference in voltage between sensed voltage pin circuit 17 for metal cased ECU pin circuit 2 for plastic cased ECU and actual injector voltage circuit 45 45A b Problem in wiring harness c ECU to harness connection problem 4 Systems Related a Ignition spark plug plug wire ignition coil b Fuel fuel type quality injector
217. n circuit 2 Function Above Max Limit 32 Pin 32 Pin MSE 1 1 Plastic Cased ECU Pin MSE 1 1 Plastic Cased ECU only circuit 2 i Code 51 Injector 1 32 Pin MSE 1 1 8 ECU grounds Plastic Cased ECU only 9 ECU j Code 52 Injector 2 32 Pin MSE 1 1 Plastic Cased ECU only Diagnostic Aid 2 FAULT CODES Refer to detailed k Code 55 MIL Light 32 Pin MSE 1 1 fault code listing before flow chart and servicing Plastic Cased ECU only information for the respective components l Code 56 Pump Relay 32 Pin MSE 1 1 Plastic Cased ECU only 1 Code 21 Engine Speed Synchronization 2 MIL circuit grounded between light and ECU 2 Code 22 Throttle Position Sensor TPS 35 Pin MA 1 7 Metal Cased ECU Pin circuit 3 Code 23 Engine Control Unit ECU 31 4 Code31 Oxygen Sensor 24 Pin MSE 1 0 Plastic Cased ECU Pin 5 Code 32 Oxygen Sensor circuit 19 6 Code 33 Fuel System temporary adaptation 32 Pin MSE 1 1 Plastic Cased ECU Pin factor circuit 29 7 Code 34 Fuel System permanent adaptation 3 ECU factor 8 Code 42 Engine Oil Temperature Sensor NOTE MIL in Metal Cased ECU systems is an LED 9 Code 43 TPS Auto Learn Initialization The MIL in Plastic Cased ECU systems must Function Below Min Limit 32 Pin MSE 1 1 be a 1 4 watt incandescent lamp Plastic Cased ECU only 10 Code 44 TPS Auto Learn Initialization Function Above Max Limit 32 Pin
218. n Crankcase 1 Crankcase breather clogged or inoperative Seals and or gaskets leaking Loose or improperly torqued fasteners Piston blowby or leaky valves confirm by inspecting components Restricted exhaust Compression Test Some of these engines are equipped with an automatic compression release ACR mechanism Because of the ACR mechanism it is difficult to obtain an accurate compression reading As an alternative perform a cylinder leakdown test Cylinder Leakdown Test A cylinder leakdown test can be a valuable alternative to a compression test By pressurizing the combustion chamber from an external air source you can determine if the valves or rings are leaking and how badly Cylinder Leakdown Tester see Section 2 is a relatively simple inexpensive leakdown tester for small engines The tester includes a quick disconnect for attaching the adapter hose and a holding tool Leakdown Test Instructions 1 Run engine for 3 5 minutes to warm it up 2 Remove spark plug s and air filter from engine 3 Rotate the crankshaft until the piston of cylinder being tested is at top dead center of the compression stroke Hold the engine in this position while testing The holding tool supplied with the tester can be used if the PTO end of the crankshaft is accessible Lock the holding tool onto the crankshaft Install a 3 8 breaker bar into the hole slot of the holding tool so it is perpendicular to both the holdi
219. ne Speed Sensor ECU Production Test Terminal Not Used Not Used Not Used TPS Initialization Terminal Engine Ground O Sensor Not Used Throttle Position Sensor Not Used Oil Temperature Sensor Not Used ECU Permanent Battery Voltage ECU Switched Battery Voltage Engine Ground Ignition Coil 2 Vehicle Ground Engine Speed Sensor Not Used Not Used Not Used Throttle Position Sensor Not Used Throttle Position Sensor Oil Temperature Sensor Power Relay Not Used Not Used Malfunction Indicator Light Not Used Vehicle Ground Not Used Fuel Injectors CON BD OF WN FR 5B 28 35 Pin ECU ALL Weather Connector 8i ie Ignition Ignition Coil 1 GIL 2 eli wr LI PS Red Red Cylinder 1 Terminal Terminal Cylinder 2 Relay Spark Plug Spark Plug Black Terminal shielded Wire Diog Lasp um AMNES aS ci a es IAE UNE See ci 1 1FJ P 1 rr A ee UE MEE AEN NE ee w PP 1 E 8g 2 18 Note C GD ADE v indle E 3 Z i a TPS Initialization D m 8 2 8 s F211 B 2 2 3 3 1 EE ars fU D fy Res 5 LI LJ See Ground Wu ov EB amp Note POSITION T Injector 1 Injector 2 Diagnostic Connector MOTOR TEMP SENSOR SENSR Inductive pick up 3 21 321 Loabde sensor Lors i See Ground ee Groun E Ch zh Note E E Note F Grounding Notes Injector Ignition Output Driver
220. new holes 7 3 N m 65 in Ib into used holes Starter Assembly Thru Bolt Torque UTE Johnson Electric Eaton Inertia Drive eeesseess 4 5 5 7 N m 40 50 in Ib Nippondenso Solenoid SMET Pom 4 5 7 5 N m 40 84 in Ib Delco kKeniy 0lenoid OD erise d d vb une Debs rbd BontiUE 5 6 9 0 N m 49 79 in Ib Mounine Screw Torque Tl emer nmr re Tere E QUERN MD DA DS 15 3 N m 135 in Ib Brush Holder Mounting Screw Torque Baro Keny oU zie IM TU 2 5 3 3 N m 22 29 in Ib Solenoid Starter Mounting Hardware Torque INTP PONG SENSO Sarte esisiini ie eei ni eE atn UR RE o Eea EE 6 0 9 0 N m 53 79 in Ib PS Fe E o E tances tes nese a screens econ nes fq RUD ee IDE DU unas 4 0 6 0 N m 35 53 in Ib Nut Positive Brush Lead Torque INTO ONGC SO at E SO M E sae 8 0 12 0 N m 71 106 in Ib Bero dide T iu rci emt Tc T 8 0 11 0 N m 71 97 in Ib Stator DV VOTE TN SCT 1 OG ences orsa Uteritucioes oceani poda ca oet bi drap UM 6 2 N m 55 in Ib Measure 6 mm 0 236 in above the bottom of the piston skirt at right angles to the piston pin Section 1 Safety and General Information Valve Cover Valve Cover Fastener Torque occid p 3 4 N m 30 in Ib Black O Ring Style Cover W ohoulder SCLC WS sas sscie su escanatenseniesti ssuncaanededecaneteavaszanabosnsdsnsssasestigeaeteniveciasactes 5 6 N m 50 in Ib wW Flange Screws and SACOG cesta ditelisied bi
221. ng 7 LES 1 phe I en i amp o k pt Piston E Expander M Figure 10 11 Installing Piston Rings Piston Ring End LA Identification Mark Top Compression Center Compression Ring sie a Expander Oil Control Ring Three piece Figure 10 12 Piston Ring Installation 1 Oil Control Ring Bottom Groove Install the expander and then the rails Make sure the ends of expander are not overlapped 2 Middle Compression Ring Center Groove Install the center ring using a piston ring installation tool Make sure the identification mark is up or the dykem stripe if contained is to the left of the end gap 3 Top Compression Ring Top Groove Install the top ring using a piston ring expender Make sure the identification mark is up or the dykem stripe if contained to the left of the end gap Connecting Rods Offset stepped cap connecting rods are used in all these engines Inspection and Service Check the bearing area big end for excessive wear score marks running and side clearances refer to Section 1 Specifications Tolerances and Special Torque Values Replace the rod and cap if scored or excessively worn Section 10 Inspection and Reconditioning Service replacement connecting rods are available in STD crankpin size and 0 25 mm 0 010 in undersize The 0 25 mm 0 010 in undersized rod can be identified by the drilled hole located in
222. ng Note B C J1 1e5 1 GROUNDING NOTES Note Item A Battery B Lambda Sensor Oo Fuel Pump o Shield pS A PD Spork Plug VA Cylinder 1 Bi 9 Lamp J1 8 hl Q 12 Volt K Line J1 13 J1 6 H 8 L Sensor d Temp Blue Motor Sensor Position Throttle Connector nostic Instruction Attached to engine block near starter The sensor grounds to the engine via the muffler If two leaded sensor is used pin 12 is lambda ground If aslip joint is used a grounding strap is required Attached to chassis Attached to engine block close to the coil Terminal ered 65 Terninal Black Cylinder 2 AN Spark Plug J1 22 J1 16 45 875 F 10A Injector 1 Injector 2 LII 87g Fuel Pump See Grounding Note C Ignition Switch F1 F Bottery 20A Gnd See Grounding Battery Note A Saftey Switch Tan Kill Lead Option No Gnd General System Installation Notes 1 The ignition switch must maintain a constant voltage to circuits 84 85 and Ji 2 as the key is swept from run position to prevent an ECU reset during starting 2 The voltage on circuits 84 85 Jl 2 and Ji 1 must remain 0 2 volts of each other regardless of system current draw to prevent differences between actuator voltages circuits 65 66 45 and 87 and system voltage J1 1 If the ignition switch controls o
223. ng areas a The pinion teeth for abnormal wear or damage b The surface between the pinion and the clutch mechanism for nicks or irregularities which could cause seal damage c Check the drive clutch by holding the clutch housing and rotating the pinion The pinion should rotate in one direction only Brushes and Springs Inspect both the springs and brushes for wear fatigue or damage Measure the length of each brush The minimum length for each brush is 7 6 mm 0 300 in See Figure 8 60 Replace the brushes if they are worn undersize or their condition is questionable Wear limit length 7 6 mm 0 300 in Figure 8 60 Checking Brushes Armature 1 Clean and inspect the commutator outer surface The mica insulation must be lower than the commutator bars undercut to ensure proper operation of the commutator See Figure 8 61 Section 8 Electrical System and Components Commutator O D Mica Insulation Figure 8 61 Commutator Mica Inspection 2 Use an ohmmeter set to the Rx1 scale Touch the probes between two different segments of the commutator and check for continuity See Figure 8 62 Test all the segments Continuity must exist between all or the armature is bad Insulation Figure 8 62 Checking Armature 3 Check for continuity between the armature coil segments and the commutator segments See Figure 8 62 There should be no continuity If continuity exists between any two the arma
224. ng or confined area Lethal Exhaust Gases Engine exhaust gases contain poisonous carbon monoxide Carbon monoxide is odorless colorless and can cause death if inhaled Avoid inhaling exhaust fumes and never run the engine in a closed building or confined area WARNING Uncoiling Spring can cause severe injury Wear safety goggles or face protection when servicing retractable starter Spring Under Tension Retractable starters contain a powerful recoil spring that is under tension Always wear safety goggles when servicing retractable starters and carefully follow instructions in the Retractable Starter Section 7 for relieving spring tension A WARNING Explosive Gas can cause fires and severe acid burns Charge battery only in a well ventilated area Keep sources of ignition away Explosive Gas Batteries produce explosive hydrogen gas while being charged To prevent a fire or explosion charge batteries only in well ventilated areas Keep sparks open flames and other sources of ignition away from the battery at all times Keep batteries out of the reach of children Remove all jewelry when servicing batteries Before disconnecting the negative ground cable make sure all switches are OFF If ON a spark will occur at the ground cable terminal which could cause an explosion if hydrogen gas or gasoline vapors are present CAUTION Electrical Shock can cause injury Do not
225. ng the oil filter Fuel Recommendations A WARNING Explosive Fuel Gasoline is extremely flammable and its vapors can explode if ignited Before servicing the fuel system make sure there are no sparks open flames or other sources of ignition nearby as these can ignite gasoline vapors Disconnect and ground the spark plug leads to prevent the possibility of sparks from the ignition system General Recommendations Purchase gasoline in small quantities and store in clean approved containers A container with a capacity of 2 gallons or less with a pouring spout is recommended Such a container is easier to handle and helps eliminate spillage during refueling Do not use gasoline left over from the previous season to minimize gum deposits in your fuel system and to ensure easy starting Do not add oil to the gasoline Do not overfill the fuel tank Leave room for the fuel to expand Fuel Type For best results use only clean fresh unleaded gasoline with a pump sticker octane rating of 87 R M 2 or higher In countries using the Research Octane Number RON it should be 90 octane minimum Leaded gasoline is not recommended and must not be used on EFI engines or on other models where exhaust emissions are regulated Gasoline Alcohol blends Gasohol up to 10 ethyl alcohol 90 unleaded gasoline by volume is approved as a fuel for Kohler engines Other gasoline alcohol blends including E20 and E85 are not to be used and not
226. ng tool and crankshaft PTO 3 4 1 Disassemble breather clean parts thoroughly check sealing surfaces for flatness reassemble and recheck pressure Replace all worn or damaged seals and gaskets Make sure all fasteners are tightened securely Use appropriate torque values and sequences when necessary Recondition piston rings cylinder bore valves and valve guides Repair replace restricted muffler exhaust system If the flywheel end is more accessible use a breaker bar and socket on the flywheel nut screw to hold it in position An assistant may be needed to hold the breaker bar during testing If the engine is mounted in a piece of equipment it may be possible to hold it by clamping or wedging a driven component Just be certain that the engine cannot rotate off of TDC in either direction 4 Install the adapter into the spark plug hole but do not attach it to the tester at this time 5 Connect an air source of at least 50 psi to the tester 6 Turn the regulator knob in the increase clockwise direction until the gauge needle is in the yellow set area at the low end of the scale 7 Connect the tester quick disconnect to the adapter hose while firmly holding the engine at TDC Note the gauge reading and listen for escaping air at the carburetor intake exhaust outlet and crankcase breather 8 Check your test results against the following table Section 3 Troubleshooting Leakdown Test Resul
227. nge fuel filter NU engines Section 5 Every 500 Hours e Have solenoid shift starter E and cleaned Section 8 Perform these maintenance procedures more frequently under extremely dusty dirty conditions Only requried for Denso starters Not necessary on Delco starters Have a Kohler Engine Service Dealer perform this service 3Cleanout Kits 25 755 20 S black or 25 755 21 S gold allow cooling areas to be cleaned without removing shrouds Storage Fill the fuel tank with clean fresh gasoline Run If the engine will be out of service for two months or the engine for 2 to 3 minutes to get stabilized more use the following storage procedure fuel into the rest of the system Close the fuel shut off valve when the unit is being stored or 1 Clean the exterior surfaces of the engine On transported Electronic Fuel Injected EFI engines avoid spraying water at the wiring harness or any of the To empty the system run the engine until the electrical components tank and the system are empty 2 Change the oil and oil filter while the engine is 4 Remove the spark plugs and add one tablespoon still warm from operation See Change Oil and of engine oil into each spark plug hole Install the Oil Filter in Section 6 spark plugs but do not connect the plug leads Crank the engine two or three revolutions 3 The fuel system must be completely emptied or the gasoline must be treated with a stabilizer 5 On equipment with an EFI engine
228. nisiieccseotstnceneoss 0 18 0 46 mm 0 0071 0 0181 in CEPS CEPS BUS CHAU Ole Vee OG EDAD erraitia errr 0 25 0 56 mm 0 0100 0 0224 in Used Bore Max CELTS C EIG20 C E20 CCET640 C E122 624 CC seeieeceicuutendisteeabe pepe s ipee arsit qtue 0 77 mm 0 030 in CH22 C H670 CH23 C H680 4078 08 jarrri 0 80 mm 0 0315 in CH25 CH26 CH735 CH730 CH740CH745 CH750 eee ne rere 0 94 mm 0 037 in Piston Thrust Face O D New CH18 CH620 CH20 CH640 CH22 624 GO uneptepeiborstde ndo pee tre 76 967 76 985 mm 3 0302 3 0309 in CEIDZ CH670 CH 235 CHGSU G74 CC xcciccsatancrotsausancraptanisoosecsscsansonacsesentenmtanae 79 963 79 979 mm 3 1481 3 1488 in CEDSCEHDGI CHZS5 CHZSU CHO TUA CEU eaten t tapa tratan 82 986 mm 3 2671 in Max Wear Limit CH18 CH620 CH20 CH640 CH22 624 0 eer ree error ere rere 76 840 mm 3 0252 in CHA CG 07E CC m 79 831 mm 3 1430 in CEDSCHZS CHAOS a Vict Ole VL A Gl WZ oe DU asado ente 82 841 mm 3 2614 in Piston Thrust Face to Cylinder Bore Running Clearance New CELTS C TEIG20 C E20 CHG40 C E122 624200 scsevacececcuntandiacnshaivapastrnsssaeseranates 0 014 0 057 mm 0 0005 0 0022 in CEHZ2 CHO CEDOCEHOS040 4 06 3 urspbnumsteated baee epson ebd ePepes 0 021 0 062 mm 0 0008 0 0024 in CH25 CH26 CH735 CH730 CH740CH745 CH7 50 een reer 0 001 0 045 mm 0 039 0 0018 in Speed Control Bracket Pastener TOFCHO oenn aA E ionaamentetanecane octantunnteaneesaes 10 7 N m 95 in Ib into
229. nt the B center terminal of rectifier regulator being condition of the part tested and the squared single end of the tandem adapter lead See Figure 8 32 6 Press the TEST button until a click is heard and then release See Figure 8 31 Momentarily one of the four lights will illuminate indicating the partial condition of the part a Ifthe OK green light comes on disconnect the tester black lead attached to one AC terminal and reconnect it to the other AC terminal Repeat the test If the OK green light comes on again the part is good and may be used b If any other light is displayed in either of the tests the rectifier regulator is faulty and should not be used Figure 8 32 NOTE A flashing LOW light can also occur as a result of an inadequate ground lead 2 Connect the tester ground lead with spring connection Make certain the connection clamp to the body of the rectifier regulator location is clean and the clamp is secure 8 24 Section 8 Electrical System and Components 25 Amp Rectifier Regulators Original Style 6 Press the TEST button until a click is heard 1 Connect the squared single end of the tandem and then release See Figure 8 3 Momentarily lead adapter to the B center red lead of one of the four lights will relight indicating the rectifier regulator being tested See Figure 8 34 partial condition of the part a Ifthe OK green light comes on disconnect the tester bl
230. ntation of the piston connecting rod assemblies inside the engine is extremely important Improper orientation can cause extensive wear or damage Be certain the pistons and connecting rods are assembled Figure 11 9 Installing Piston Assembly Using Ring exactly as shown in Figure 11 8 Compressor Tool 1 Stagger the piston rings in the grooves until the 5 Install the inner rod cap to the connecting rod end gaps are 120 apart The oil ring rails should using the two hex flange screws Three different also be staggered types of connecting rod bolts have been used and each has a different torque value If 8 mm straight shank type bolts are used torque in increments to 22 7 N m 200 in Ib If 8 mm step down bolts are used torque in increments to 14 7 N m 130 in Ib If 6 mm straight shank bolts are n used torque in increments to 11 3 N m 100 in lb Illustrated instructions are provided in the service rod package See Figures 11 10 and 11 11 NOTE Align the chamfer of the connecting rod with the chamfer of its mating end cap When installed the flat faces of the connecting rods should face each other The faces with the raised rib should be Cylinder 1 Figure 11 8 Piston Connecting Rod and End Cap toward the outside Detail Section 11 Reassembly Torque these to 22 7 N m 200 in Ib 8 mm Straight Shank Torque these to 14 7 N m 130 in Ib 8 mm Step Down Torque these to 11 3 N m 100 in
231. o be drained prior to bowl removal by loosening removal of the bowl drain screw See Figure 5 21 Figure 5 22 Removing Float and Inlet Needle 3 Usean appropriate size flat screwdriver and carefully remove the two main jets from the carburetor Note and mark the jets by location for proper reassembly The main jets may be size side specific After the main jets are removed the main nozzles can be removed out through the bottom of the main towers Note the orientation direction of the nozzles The end with the two raised shoulders should be out down adjacent to the main jets Save the parts for cleaning and Fuel Bowl reuse 5ee Figure 5 23 Bowl Drain Screw Figure 5 21 Fuel Bowl Removed From Carburetor tr Nozzles Main Jets te Figure 5 23 Main Jets and Nozzles Removed 5 15 Section 5 Fuel System and Governor 4 Remove the screw securing the flat washer and ground lead if equipped from the top of the carburetor then carefully pull lift out the two slow jets The slow jets may be sized side specific mark or tag for proper reassembly Note the small O Ring on the bottom of each jet See Figures 5 24 and 5 25 Save parts for cleaning and reuse unless a Jet Kit is also being installed Clean the slow jets using compressed air Do not use wire or carburetor cleaner Clean the carburetor body main jets vent ports seats etc using a good commercially available carburetor solvent Keep away
232. o consecutive teeth missing is mounted on the flywheel The inductive speed sensor is mounted 1 5 0 25 mm 0 059 0 010 in away from the ring gear During rotation an AC voltage pulse is created within the sensor for each passing tooth The ECU calculates engine speed from the time interval between the consecutive pulses The two tooth gap creates an interrupted input signal corresponding to specific crankshaft position 84 BTDC for cylinder 1 This signal serves as a reference for the control of ignition timing by the ECU Synchronization of the inductive speed pickup and crankshaft position takes place during the first two revolutions each time the engine is started The sensor must be properly connected at all times If the sensor becomes disconnected for any reason the engine will quit running Service The engine speed sensor is a sealed non serviceable assembly If Fault Code diagnosis indicates a problem within this area check and test as follows 1 Check the mounting and air gap of sensor It must be 1 5 mm 0 25 mm 0 059 0 010 in 2 Inspect the wiring and connections for damage or problems 3 Make sure the engine has resistor type spark plugs 4 Disconnect main harness connector from ECU 5B 6 5 Connect an ohmmeter between the designated pin terminals in the plug 35 Pin MA 1 7 Metal Cased ECU 3 and 21 pin terminals 24 Pin MSE 1 0 Plastic Cased ECU 9 and 10 pin
233. o the 86 terminal in relay connector see Figure 5B 14 Set meter to test resistance Rx1 Turn ignition switch from off to on Meter should indicate continuity ground circuit is completed for 1 to 3 seconds Turn key switch back off 5B 13 Section 5B EFI Fuel System Terminal 85 Terminal 87 6 Attach ohmmeter leads to the 230 and 287 Ignition Switch E T Feed To Ignition terminals in relay Initially there should be no Voltage n Coils Fuel continuity Using a 12 volt power supply connect N Injectors and the positive lead to the 85 terminal and Fuel Pump touch the negative lead to the 86 terminal 3 When 12 volts is applied the relay should Terminal 86 activate and continuity should exist circuit Terminal 87AZ ECU made between the 30 and 87 terminals Repeat Not used E Controlled the test several times If at any time the relay fails Ground to activate the circuit replace the relay Terminal 30 Fuel Injectors Permanent Battery Voltage Figure 5B 14 Relay Connector a Clean the connection and check wiring if circuit was not completed 3 Set meter for DC voltage Touch red tester lead to the 30 terminal in relay connector A reading of 12 volts should be indicated at all times 4 Connect red lead of meter to the 85 terminal in relay connector Turn key switch to the on position Battery voltage should be present a No voltage present indicates
234. od idea to write down the codes as they appear as they may not be in numerical sequence b Code 61 will always be the last code displayed indicating the end of code transmission If code 61 appears immediately no other fault codes are present Section 5B EFI Fuel System Example of Diagnostic Display 1 Diagnostic display initiated through ignition key sequencing 2 f Jo Short Pauses wm k Toara 9 9 9 ow wo 6 im Light remains on at end of transmission Figure 5B 43 After the problem has been corrected the fault codes may be cleared as follows 1 Disconnect the negative battery cable from battery terminal or remove the main fuse for the ECU for approximately 1 minute 2 Reconnect the cable and tighten securely or reinstall the main fuse Start the engine and allow it to run for several minutes The MIL should remain off if the problem was corrected and the fault codes should not reappear codes 31 32 33 and 34 may require 10 15 minutes of running to reappear The following chart lists the fault codes what they correspond to and what the visual indications will be Following the chart is a list of the individual codes with an explanation of what triggers them what symptoms might be expected and the probable causes Diagnostic Code Summary OBD2 35 Pin 24 Pin Q2 Pin P Code Ap MA 1 7 MSE 1 0 plicable to Connection or Failure Description Metal Plastic 32 Pin MSE Cased
235. oes not flow from the line check the b Hold the line below the bottom of the tank fuel tank vent fuel pickup screen in line filter Open the shut off valve if so equipped and shut off valve and fuel line Correct any observed observe flow problem and reconnect the line Check the operation of fuel pump If fuel does flow from the line check for faulty a Remove the fuel line from the inlet fitting of carburetor Refer to the Carburetor portions of carburetor this section b Crank the engine several times and observe flow If fuel does not flow from the line check for a clogged fuel line If the fuel line is unobstructed check for overfilled crankcase and or oil in pulse line If none of the checks reveal the cause of the problem replace the pump 5 2 Fuel Pump General These engines are equipped with either a pulse or mechanical fuel pump See Figures 5 1 and 5 2 The pumping action is created by either the oscillation of positive and negative pressures within the crankcase through a hose or by direct lever pump actuation off rocker arm movement The pumping action causes the diaphragm on the inside of the pump to pull fuel in on its downward stroke and to push it into the carburetor on its upward stroke Internal check valves prevent fuel from going backward through the pump Outlet Line to Carburetor Pulse Fuel Pump Inlet Line Figure 5 1 Pulse Style Fuel Pump Performance Minimum fuel delivery
236. ol adjustments following the appropriate instructions covered in this section 2 Move the throttle control to the idle position Hold the governor lever away from the carburetor or hold the throttle lever so it is tight against the idle speed adjusting screw to negate the governor activation See Figure 5 7 Check the speed with a tachometer and adjust it to 1500 RPM 3 Release the governor lever and allow the engine to return to the governed idle speed Check it with a tachometer against the equipment manufacturers recommended idle speed Governed Idle Speed RPM is typically 300 RPM approximate higher than the low idle speed If adjustment is necessary bend the adjusting tab on the speed control assembly to set See Figure 5 6 Section 5 Fuel System and Governor C F Hold Throttle Lev r Against Figure 5 7 Holding Throttle Lever Against Idle Stop Screw One Barrel Carburetor Servicing Float It is not necessary to remove the carburetor from the engine to check and adjust the float 1 Remove the air cleaner and breather hose Refer to Section 9 Disassembly 2 Disconnect the fuel line from the carburetor See Figure 5 8 3 Clean dirt and debris from exterior of carburetor 4 Remove the four screws holding the two carburetor halves together Carefully lift the upper body off the carburetor body and disconnect choke linkage 5 7 Section 5 Fuel System and Governor Figure 5 8 Car
237. on module air gap is critical to proper system performance Do not attempt to set it with a business card or folded microfiche card use the feeler gauge specified 5 Loosen the mounting screws allow the magnet to pull the module down against the feeler gauge and retighten the mounting screws 6 Rotate the flywheel to remove the feeler gauge position the magnet back under the module and recheck that the specified gap minimum of 0 28 mm 0 011 in exists under each leg of the module When you are certain the gap is correct torque the module mounting screws to 4 0 N m 35 in Ib On a twin cylinder engine repeat these 6 steps to set the opposite side ignition module 6 Reattach the lead wires to the ignition module s noting if resistance is felt indicating a snug fit between the male and female terminals If any connections do not feel snug disconnect the lead lightly pinch the female terminal with a pliers and recheck the fit 7 When the integrity of all connections has been verified repeat the spark test Test 2 a Ifastrong steady spark is now present both sides on a twin your problem should be corrected Go to step 4 of Test 5 b Ifthere is still a spark problem perform all of Test 5 Test 5 Test the SAM 1 Trace the red power source lead from the SAM to the harness connection Separate the connector and connect the red lead of a DC voltmeter to the harness terminal Trace the ground lead fro
238. oning properly 1 Shut off fuel and remove the solenoid from the carburetor When the solenoid is loosened and removed gas will leak out of the carburetor Have a container ready to catch the fuel 2 Wipe the tip of the solenoid with a shop towel or blow it off with compressed air to remove any remaining fuel Take the solenoid to a location with good ventilation and no fuel vapors present You will also need a 12 volt power source that can be switched on and off 5 5 Section 5 Fuel System and Governor 3 Besure the power source is switched off Connect the positive power source lead to the red lead of the solenoid Connect the negative power source lead to the solenoid bracket 4 Turn the power source on and observe the pin in the center of the solenoid The pin should retract with the power on and return to its original position with the power off Test several times to verify operation Carburetor Adjustments CH18 740 General In compliance with government emission standards the carburetor is calibrated to deliver the correct air to fuel mixture to the engine under all operating conditions The high speed mixture is preset and cannot be adjusted Pre compliance carburetors contain a low idle fuel adjusting needle on certified compliance carburetors both the low and high speed mixture circuits are pre established and cannot be adjusted The low idle speed RPM is the only adjustment available See F
239. onnections safety interlocks etc Section 8 Electrical System and Components b If the problem persists the condition is Test 3 Check for timing advance associated with the ignition or electrical system of the engine Leave the kill lead isolated until all testing is completed NOTE If the engine starts or runs during any of the testing you may need to ground the kill lead to shut it down Because you have interrupted the kill circuit it may not stop using the switch Test 2 Test for spark 1 With the engine stopped disconnect one spark plug lead Connect the spark plug lead to post terminal of spark tester see Section 2 and attach tester clip to a good engine ground Figure 8 8 NOTE Iftwo testers are available testing can be performed simultaneously for both cylinders However if only one tester is available two individual tests must be performed The side not being tested must have the spark plug lead connected or grounded Do not crank the engine or perform tests with one spark plug lead disconnected and not grounded or permanent system damage may occur 1 Makea line near the edge of the flywheel screen with a marking pen or narrow tape 2 Connect an automotive timing light to cylinder that had good spark 2 Crank the engine over establishing a minimum of 550 600 RPM and observe tester s for spark 3 Onatwin cylinder engine repeat the spark test on the opposite cylinder if cylinders are be
240. ons are more likely the cause of operating problems and system errors than an actual component Refer to the Troubleshooting Electrical section for additional information Battery Charging System EFI engines are equipped with either a 15 or 25 amp charging system to accommodate the combined electrical demands of the ignition system and the specific application Charging system troubleshooting information is provided in Section 8 Section 5B EFI Fuel System Fuel Components Fuel Pump External Internal Figure 5B 26 Fuel Pump Styles General An electric fuel pump is used to transfer fuel in the EFI system Depending on the application the pump may be inside the fuel tank or in the fuel line near the tank The pumps are rated for a minimum output of 25 liters per hour at 39 psi The pumps have an internal 60 micron filter In addition the in tank style pumps will have a pre filter attached to the inlet In line pump systems may also have a filter ahead of the pump on the pick up low pressure side The final filter is covered separately on page 5B 22 When the key switch is turned on and all safety switch requirements are met the ECU through the relay activates the fuel pump which pressurizes the system for start up If the key switch is not promptly turned to the start position the engine fails to start or the engine is stopped with the key switch on as in the case of an accident the ECU switches off
241. oose or leaking d Excessive internal engine wear 5 Faulty regulator a Primary valve not opening b Diaphragm spring adjustment incorrect c Idle adjustment screw incorrectly set d Vent s blocked restricted 6 Restricted blocked fuel line Blocked carburetor fuel circuit 8 Loose leaking fuel enrichment hose Impco carburetor system pa Hard starting runs roughly or stalls at idle speed 1 LPG fuel tank low 2 Vacuum line between carburetor and regulator pinched cracked or leaking 3 Carburetor idle speed set too low should be at least 1200 RPM 4 Carburetor idle circuit restricted 5 Dirty restricted air cleaner 6 Dirty restricted lock off filter 7 Frozen malfunctioning regulator Check adjust primary pressure 8 Excessive external load on engine 9 Excessive internal wear 10 Loose leaking fuel enrichment hose Impco carburetor system Irregular or inconsistent idle 1 Improper operation adjustment of regulator idle adjustment screw throttle opening and or engine governor 2 Secondary valve in regulator not closing Readjust idle screw couterclockwise so valve can close fully against seat 3 Loose leaking vacuum line 4 Loose carburetor mounting and or line connections 5 Damaged diaphragm s within regulator 6 Debris in regulator Flush debris from drain plug or remove regulator from system disassemble body and remove debris 7 Dirt or debris in carburetor Remove carburet
242. or disassemble and clean service as required If venturi Impco carburetor removal is performed mark its orientation to the carburetor body for proper reinstallation 8 Loose leaking fuel enrichment hose Impco carburetor system Section 5A LPG Fuel Systems Engine stalls during operation LPG Carburetor Adjustments 1 No fuel 2 Faulty lock off or blocked filter General 3 Improper governor setting The LPG carburetor and regulator are designed to 4 Damaged diaphragms within regulator deliver the correct fuel to air mixture to the engine 5 Vacuum line leaking loose or pinched under all operating conditions The high and low idle 6 Restricted fuel line fuel mixture settings are preset at the factory and 7 Loose leaking fuel enrichment hose Impco cannot be adjusted These engines are equipped with carburetor system an Impco or Nikki carburetor See Figure 5A 2 and 5A 3 Although both carburetors function similarly Low power each is unique and should not be interchanged 1 Air cleaner or exhaust system dirty restricted 2 Low fuel 3 Rich gas condition flooding through regulator a Dirty restricted valves in regulator b Damaged primary diaphragm in regulator 4 No fuel a Electric lock off not opening filter blocked or restriction within fuel line b Leaking loose or cracked vacuum line from carburetor to regulator Load Block Assembly c Leaking or loose intake system components d Regulator primar
243. or this system operates in the same fashion as the fixed timing module except the trigger circuit for the semiconductor L2 Figure 8 5 is replaced by the spark advance module Figure 8 7 8 7 Section 8 Electrical System and Components The pulse generated by the input coil of the ignition module L1 Figure 8 5 is fed to the input of the conditioning circuit The conditioning circuit shapes this pulse putting it in a useable form for the additional circuits This pulse starts the charge pump which charges a capacitor in a linear fashion that can be directly related to the engine speed At the same time the pulse resets the delay circuit for length of the pulse width The comparator is off during this period and no output is generated As soon as the original pulse drops back to zero the capacitor in the delay circuit begins to charge When the charge on the delay capacitor exceeds the charge on the charge pump capacitor the comparator changes state activating the pulse generator This pulse turns ON the CD ignition module semiconductor Energy is then transferred to the secondary of the output transformer T1 Figure 8 5 The high voltage pulse generated here is delivered to the spark plug causing arcing of the spark gap and igniting the fuel air mixture in the combustion chamber As the trigger pulse is generated all associated circuits are reset their capacitors discharged The longer it takes the delay circuit to surpass
244. ore removing each spark plug clean the area around the base of the plug to keep dirt and debris out of the engine Normal and fouled plugs are shown in the following 2 Remove the plug and check its condition See photos Inspection following this procedure Replace the plug if necessary 8 1 Section 8 Electrical System and Components Normal A plug taken from an engine operating under normal conditions will have light tan or gray colored deposits If the center electrode is not worn a plug in this condition could be set to the proper gap and reused Carbon Fouled Soft sooty black deposits indicate incomplete combustion caused by a restricted air cleaner over rich carburetion weak ignition or poor compression Worn On a worn plug the center electrode will be rounded and the gap will be greater than the specified gap Replace a worn spark plug immediately 8 2 Wet Fouled A wet plug is caused by excess fuel or oil in the combustion chamber Excess fuel could be caused by a restricted air cleaner a carburetor problem or operating the engine with too much choke Oil in the combustion chamber is usually caused by a restricted air cleaner a breather problem worn piston rings or valve guides Overheated Chalky white deposits indicate very high combustion temperatures This condition is usually accompanied by excessive gap erosion Lean carburetor settings an intake air leak or incorrect s
245. orque the screw to 3 9 N m 35 in Ib See Figure 11 56 Figure 11 54 Connecting Kill Leads on Standard Ignition Modules Figure 11 56 Installing Breather Reed Assembly 4 Insert the breather filter into position in the crankcase Make sure no filter strands are on the sealing surface See Figure 11 57 5 Install the new breather gasket Figure 11 55 Connect Leads on SMART SPARK Ignition Modules Install Breather Cover and Inner Baffles RTV sealant was used on early models between the breather cover and the crankcase A gasket with imprinted sealant beads is now used and recommended Install as follows Figure 11 57 Installing New Breather Filter 1 Besure the sealing surfaces of the crankcase and 6 Carefully position the breather cover on the breather cover are clean of old gasket material or crankcase Install first two hex flange screws RTV sealant Do not scrape the surfaces as this at positions shown in Figure 11 58 and finger could result in leakage tighten at this time 2 Check to make sure there are no nicks or burrs on sealing surfaces 11 16 Section 11 Reassembly Install Blower Housing and Outer Baffles NOTE Do not completely tighten screws until all items are installed to allow shifting for hole alignment 1 Connect the plug to the key switch in the blower housing if so equipped 2 Slide the blower housing into position over the front edge of the inner baffles See Figure 11
246. ounds B ECU 5B 46 Diagnostic Aid 7 IGNITION SYSTEM no spark Possible causes 1 Spark plug 2 Plug wire 3 Coil 4 Coil circuit s 35 Pin MA 1 7 Metal Cased ECU Circuits 1 19 40 40A 43 and relay 24 Pin MSE 1 0 Plastic Cased ECU Circuits 22 23 65 66 30 and relay 32 Pin MSE 1 1 Plastic Cased ECU Circuits 30 31 65 66 relay and relay circuit 30 5 ECU grounds 6 ECU Diagnostic Aid 8 FUEL SYSTEM ELECTRICAL no fuel delivery Possible causes 1 No fuel Air in fuel rail Fuel valve shut off Fuel filter line plugged Injector circuit s 35 Pin MA 1 7 Metal Cased ECU Circuits 35 35A 45 and 45A 24 Pin MSE 1 0 Plastic Cased ECU Circuits 16 17 45 and 45A 32 Pin MSE 1 1 Plastic Cased ECU Circuits Ohi DD qud 14 15 and 45 6 Injector 7 ECU grounds o ECU Diagnostic Aid 9 FUEL SYSTEM fuel pressure Possible causes for low fuel system pressure 1 Low fuel 2 Fuel filter plugged 3 Fuel supply line plugged 4 Pressure regulator 5 Fuel pump Possible causes for high fuel system pressure 1 Pressure regulator 2 Fuel return line plugged or restricted Diagnostic Aid 10 BASIC ENGINE cranks but will not run Possible causes 1 Refer to basic engine troubleshooting charts within service manual sections 3 5 and 8 Section 6 Lubrication System General This engine uses a full pressure lubrication
247. ow crankcase oil level High crankcase oil level Faulty carburetor Lean fuel mixture SMART SPARK malfunction applicable models Engine Knocks 1 UO ie Se I Excessive engine load Low crankcase oil level Old or improper fuel Internal wear or damage Hydraulic lifter malfunction Quality of fuel Incorrect grade of oil Engine Loses Power 1 po euo iT qvo 9 3 2 Low crankcase oil level High crankcase oil level Dirty air cleaner element Dirt or water in the fuel system Excessive engine load Engine overheated Faulty spark plugs Low compression Exhaust restriction SMART SPARK malfunction applicable models Low battery Incorrect governor setting Engine Uses Excessive Amount of Oil 1 eb UM a D9 Incorrect oil viscosity type Clogged or improperly assembled breather Breather reed broken Worn or broken piston rings Worn cylinder bore Worn valve stems valve guides Crankcase overfilled Blown head gasket overheated Oil Leaks from Oil Seals Gaskets pq gg s Crankcase breather is clogged or inoperative Breather reed broken Loose or improperly torqued fasteners Piston blowby or leaky valves Restricted exhaust External Engine Inspection Before cleaning or disassembling the engine make a thorough inspection of its external appearance and condition This inspection can give clues to what might be found inside the engine and the cause when it i
248. owl Drain Screw Figure 5 15 Fuel Bowl Removed From Carburetor Figure 5 14 Holding Throttle Lever Against Idle Stop Screw Two Barrel Carburetor 5 13 Section 5 Fuel System and Governor 3 Remove the float pin screw and lift out the old float pin and inlet needle See Figure 5 16 Discard all of the parts The seat for the inlet needle is not serviceable and should not be removed Figure 5 16 Removing Float and Inlet Needle 4 Clean the carburetor bowl and inlet seat areas as required before installing the new parts 5 Attach the inlet needle to the plastic tang of the float with the wire clip The formed 90 lip should point up with the needle valve hanging down See Figure 5 17 Figure 5 17 Float and Inlet Needle Details 6 Install the float and inlet needle down into the seat and carburetor body Install the new pivot pin through the float hinge and secure with the new retaining screw See Figure 5 18 5 14 Figure 5 18 Installing Float Assembly 7 Hold the carburetor body so the float assembly hangs vertically and rests lightly against the fuel inlet needle The inlet needle should be fully seated but the center pin of the needle on retainer clip end should not be depressed Check the float height adjustment NOTE The inlet needle center pin is spring loaded Make sure the float rests against the fuel inlet needle without depressing the center pin The correct float height
249. parately Resistance value should between the electrodes and sent to the ECU The again be 2375 2625 voltage signal tells the ECU if the engine is straying from the ideal 14 7 1 fuel mixture and the ECU then a If the resistance is out of specifications adjusts the injector pulse accordingly replace the temperature sensor b If itis within specifications proceed to Step 6 6 Check the temperature sensor circuits input ground from the main harness connector to the corresponding terminal in the sensor plug for continuity damage etc CNW E SAX 35 Pin MA 1 7 Metal Cased ECU Pin circuits 14 and 27 1 Connection Cable 5 Contact Element 2 Disc Spring 6 Sensor Housing 24 Pin MSE 1 0 Plastic Cased ECU Pin 3 Ceramic Support Tube 7 Active Ceramic Sensor circuits 6 and 4 4 Protective Sleeve 8 Protective Tube 32 Pin MSE 1 1 Plastic Cased ECU Pin Figure 5B 12 Cutaway of Oxygen Sensor circuits 6 and 4 The oxygen sensor can function only after being heated by exhaust temperatures to a minimum of 375 C 709 F A cold oxygen sensor will require approximately 1 2 minutes at moderate engine load to warm sufficiently to generate a voltage signal Proper grounding is also critical The oxygen sensor grounds through the metal shell so a good solid unbroken ground path back through the exhaust system components engine and wiring harness is required Any disruption or break in the groun
250. park timing are normal causes for high combustion temperatures Section 8 Electrical System and Components Battery 2 Keep the cables terminals and external surfaces of the battery clean A build up of corrosive acid General or grime on the external surfaces can cause the A 12 volt battery with 400 cold cranking amps is battery to self discharge Self discharge occurs generally recommended for starting in all conditions rapidly when moisture is present A smaller capacity battery is often sufficient if an application is started only in warmer temperatures 3 Wash the cables terminals and external surfaces Refer to the following table for minimum capacities with a mild baking soda and water solution cca based on anticipated ambient temperatures Rinse thoroughly with clear water The actual cold cranking requirement depends on engine size application and starting temperatures NOTE Do not allow the baking soda solution The cranking requirements increase as temperatures to enter the cells as this will destroy the decrease and battery capacity shrinks Refer also to electrolyte the operating instructions of the equipment being this engine powers for specific battery requirements Battery Test To test the battery you will need a DC voltmeter Battery Size Recommendations Perform the following steps See Figure 8 2 1 Connect the voltmeter across the battery Above 32 F 00 0 F to 32 F 18 C to 0 C 2 Crank the engine If the
251. per type and weight of oil in the crankcase is extremely important So is checking oil daily and changing oil regularly Failure to use the correct oil or using dirty oil causes premature engine wear and failure Oil Type Use high quality detergent oil of API American Petroleum Institute Service Class SG SH SJ or higher Select the viscosity based on the air temperature at the time of operation as shown in the following table RECOMMENDED SAE VISCOSITY GRADES 10W 30 C m 20 TEMPERATURE RANGE EXPECTED BEFORE NEXT OIL CHANGE Use of synthetic oil having 5W 20 or 5W 30 rating is acceptable up to 4 C 40 F Synthetic oils will provide better starting in extreme cold below 23 C 10 F NOTE Using other than service class SG SH SJ or higher oil or extending oil change intervals longer than recommended can cause engine damage NOTE Synthetic oils meeting the listed classifications may be used with oil changes performed at the recommended intervals However to allow piston rings to properly seat a new or rebuilt engine should be operated for at least 50 hours using standard petroleum based oil before switching to synthetic oil A logo or symbol on oil containers identifies the API service class and SAE viscosity grade See Figure 1 3 SA Figure 1 3 Oil Container Logo 1 4 Refer to Section 6 Lubrication System for detailed procedures on checking the oil changing the oil and changi
252. pin for size taper and out of round NOTE Ifthe crankpin is reground visually check to ensure that the fillet blends smoothly with the crankpin surface See Figure 10 1 High Point from Fillet Intersections The Fillet Must Blend Smoothly with the Bearing 45 Journal Surface Minimum This Fillet Area Must Be Completely Smooth Figure 10 1 Crankpin Fillets The connecting rod journal can be ground one size under When grinding a crankshaft grinding stone deposits can get caught in the oil passages which could cause severe engine damage Removing the crankpin plug when the crankshaft is ground provides easy access for removing any grinding deposits that may collect in the oil passages Use the following procedure to remove and replace the plug 10 2 Procedure to Remove Crankshaft Plug 1 Drill a 3 16 hole through the plug in the crankshaft 2 Thread a 3 4 or 1 long self tapping screw with a flat washer into the drilled hole The flat washer must be large enough to seat against the shoulder of the plug bore See Figure 10 2 3 Tighten the self tapping screw until it draws the plug out of the crankshaft Procedure to Install New Plug 1 Usea single cylinder camshaft pin Kohler Part No 47 380 09 S as a driver and tap the plug into the plug bore until it seats at the bottom of the bore Make sure the plug is tapped in evenly to prevent leakage Self Tapping Screw Flat Washer Crankshaft Figu
253. plication whenever it appears dirty typically every other involved Two adapters are shown in time the main element is replaced Clean the area Figure 4 14 around the base of the inner element before removing it so dirt does not get into the engine 4 5 Section 4 Air Cleaner and Air Intake System Figure 4 14 Adapters for Heavy Duty Air Cleaners Air Intake Cooling System To ensure proper cooling make sure the grass screen cooling fan fins and external surfaces of the engine are kept clean at all times Every 100 hours of operation more often under extremely dusty or dirty conditions remove the blower housing and other cooling shrouds Clean the cooling fins and external surfaces as necessary Make sure the cooling shrouds are reinstalled 4 6 Cleanout kits Kohler Part No 25 755 20 S black or 25 755 21 5 gold are recommended to aid inspection and cleanout of the cooling fins See Figure 4 15 NOTE Operating the engine with a blocked grass screen dirty or plugged cooling fins and or cooling shrouds removed will cause engine damage due to overheating Figure 4 15 Cleanout Kit Installed on Blower Housing Section 5 Fuel System and Governor Description The Command horizontal twins use three different types of fuel systems carbureted electronic fuel injection EFI or gaseous Gaseous fuel systems can be either liquefied petroleum gas LPG or LP or natural gas NG Some dual fuel
254. powered circuit Cie lights horn it is recommended that a relay be used to control the power 3 To prevent signal errors load circuits ie horn lights shall not be powered from the EFI engine or wire chassis harness 4 A resistive spark plug with either a resistive spark plug wire or boot must be used to prevent electrical system noise 9 It is recommend that the ECU housing be mounted vertically with the wire bundle down or horizontally with the weother pok connector down 6 It is recommended that the ECU not be mounted to the engine but be attached it an isolator plate or or bracket that con keep the vibrations within the ECU specs 7 When not in operation the battery must maintain a minimum system voltage of 7 volts with a current draw of 2mA to maintain the adaptive memory 8 During start the battery must maintain 7 volts minimum for the ECU operations during crank 9 Unless otherwise specified All wires are 18AWG 10 gt Inductive pickup wires pin9 and 10 are to be o twisted pair with 1 twist per inch 1D Diagnosis lamp is to be o 12V 1 4A incandescent lamp 12 Normal Operational Voltage is 16Vdc 9Vdc With a cold cranking dc voltage of 7Volts 13 TPS connection shown is for counter clockwise rotation of the TPS Clockwise rotaion requires switching wires to TPS pins 1 amp 2 Section 5B EFI Fuel System 24 Pin MSE 1 0 Plastic Cased ECU Systems Pin Function Permanent Battery Voltage Switched Igni
255. ps and or technicians Check state and local regulations before attempting any adjustment service or repair of the LPG system or components Faulty repairs by unqualified or underqualified personnel can have very serious ramifications The information in this segment is for the exclusive use of qualified LPG service providers Proper service and repair of LPG fuel systems requires qualified technicians and special equipment Many states 5A LPG Fuel System Components The typical liquid withdrawal LPG fuel system consists of the following components e LPG Fuel Tank Liquid Withdrawal Electric Lock Off Filter Assembly Vaporizer LPG Regulator Combination Primary Secondary Vacuum Lock Off LPG Carburetor High Pressure Fuel Line s Vacuum Line Fuel Line Vaporizer p h EN Vacuum Line Lock Off Filter Assembly LPG Regulator Figure 5A 1 5A 1 Section 5A LPG Fuel Systems Operation In a liquid withdrawal system the Liquefied Petroleum Gas LPG is released from the bottom of the supply tank under high pressure Upon opening the shut off valve on the tank liquid fuel travels out through the high pressure line to the electric lock off filter assembly The lock off opens internally when the key switch is turned on permitting filtered fuel to flow to the vaporizer The vaporizer is mounted in the flow of the discharged cooling air It absorbs heat from the cooling air and transfers it to the fuel changing the li
256. pulley and housing Figure 7 6 Removing Pulley from Housing 7 3 Section 7 Retractable Starter 8 Note the position of the spring and keeper assembly in the pulley See Figure 7 7 Remove the spring and keeper assembly from the pulley as a package A WARNING Spring Under Tension Do not remove the spring from the keeper Severe personal injury could result from the sudden uncoiling of the spring Rope Hole Figure 7 7 Position of Spring and Keeper in Pulley Inspection and Service 1 Carefully inspect the rope pawls housing center screw and other components for wear or damage 2 Replace all worn or damaged components Use only genuine Kohler replacement parts as specified in the Parts Manual All components shown in Figure 7 1 are available as service parts Do not use nonstandard parts 3 Do not attempt to rewind a spring that has come out of the keeper Order and install a new spring and keeper assembly 4 Clean all old grease and dirt from the starter components Generously lubricate the spring and center shaft with any commercially available bearing grease 7 4 Reassembly E Make sure the spring is well lubricated with grease Place the spring and keeper assembly inside the pulley with spring towards pulley See Figure 7 7 Install the pulley assembly into the starter housing See Figure 7 8 Make sure the pulley is fully seated against the starter housing Do not wind the pulley and
257. quefied petroleum to a vapor or gaseous state while partially stepping down the fuel pressure The gas vapor flows under this decreased pressure to the regulator where it is further reduced to a usable regulated pressure The regulator activated by intake manifold vacuum controls fuel flow to the carburetor In the venturi of the carburetor the fuel vapor is mixed with incoming air from the air cleaner in the correct ratio for efficient combustion Troubleshooting Checklist If the engine starts hard runs roughly or stalls check the following areas e Make sure the LPG fuel tank is filled and shut off valve is fully opened e Make sure fuel is reaching the carburetor e Make sure the air cleaner element and precleaner are clean and all components are fastened securely e Make sure the ignition governor exhaust throttle and choke control systems are all operating properly e Check compression If engine continues to start hard run roughly or stall after these checks have been made use the following troubleshooting guide Engine cranks but will not start 1 LPG fuel tank closed low or empty 2 Lock off not opening electrically preventing fuel flow to vaporizer 3 Fuel filter located inside lock off dirty or blocked 5A 2 4 Insufficient vacuum signal regulator not opening a Vacuum line between carburetor and regulator cracked leaking kinked or pinched b Carburetor loose c Intake manifold l
258. quence shown in Figure 11 17 A different procedure will have to be followed to check and adjust crankshaft end play on these models P I li i Figure 11 16 Thrust Bearing Washer and Shim Used on Some Models Section 11 Reassembly Thrust Shim Thrust Washer Needle Thrust Bearing Bearing Race WM Closure N Z gt Plate SW X Figure 11 17 Correct Sequence of Thrust Bearing Washer and Shim in Closure Plate The race for the thrust bearing presses loosely into the closure plate If it is not already installed push it into the crankshaft bore inside the closure plate Pack the thrust bearing with heavy grease and stick the bearing into the race Wipe some grease on the face of the thrust washer and stick it onto the thrust bearing Wipe some grease on the face of the original shim spacer and stick it onto the thrust washer Install the closure plate onto the crankcase without applying RTV sealant and secure it with only two or three of the fasteners at this time Use a dial indicator to check the crankshaft end play End play should be 0 05 0 50 mm 0 0020 0 0197 in except for CH25 engines below Serial No 2403500008 end play should be 0 050 0 75 mm 0 0020 0 0295 in Shim spacers are available in the three color coded thicknesses listed below if adjustment is needed Crankshaft End Play Shims GREEN 0 8366 0 9127 mm 0 8750 mm 0 034 in Nominal YELLOW 1 0652 1
259. quipped is fully opened 4 Make sure battery is supplying proper voltage 5 Check that the fuses are good and that all electrical and fuel line connections are good 6 Testfuel pump and relay operation as described earlier under Fuel Pump Service 5B 34 Fault Codes The ECU continuously monitors engine operation against preset performance limits If the operation is outside the limits the ECU activates the MIL and stores a diagnostic code in its fault memory If the component or system returns to proper function the ECU will eventually self clear the fault code and turn off the MIL If the MIL stays illuminated it warns the customer that dealer service is required Upon receipt the dealer technician can access the fault code s to help determine what portion of the system is malfunctioning The 2 digit blink codes available based upon the style of ECU are listed on pages 5B 35 55 37 The codes are accessed through the key switch and displayed as blinks or flashes of the MIL Access the codes as follows 1 Start with the key switch off 2 Turn the key switch on off on off on leaving it on in the third sequence The time between sequences must be less than 2 5 seconds 3 Any stored fault codes will then be displayed as a series of MIL blinks from 2 to 6 representing the first digit followed by a pause and another series of blinks from 1 to 6 for the second digit see Figure 5B 43 a It s a go
260. quired 4 Remove the two screws securing the air cleaner base to throttle body manifold Remove the air cleaner base to permit access to the injectors Check condition of air cleaner base gasket replace if necessary 5 Remove the flywheel screen if it overlaps the blower housing 6 If the engine has a radiator type oil cooler mounted to the blower housing remove the two oil cooler mounting screws 7 Remove the blower housing mounting screws Note the location of the plated silver screw attaching the rectifier regulator ground lead Remove the blower housing 8 Thoroughly clean the area around and including the throttle body manifold and the injectors 9 Disconnect the throttle linkage and damper spring from the throttle lever Disconnect the TPS lead from the harness 10 Remove the manifold mounting bolts and separate the throttle body manifold from the engine leaving the TPS fuel rail air baftle injectors and line connections intact Discard the old gaskets 11 Position the manifold assembly over an appropriate container and turn the key switch on to activate the fuel pump and pressurize the system Do not turn switch to start position 12 If either injector exhibits leakage of more than two to four drops per minute from the tip or shows any sign of leakage around the outer shell turn the ignition switch off and replace injector as follows 13 Depressurize the fuel system following the procedur
261. r and replace with a genuine Kohler filter every 200 operating hours Fuel Line These engines use low permeation rated fuel lines certified to comply with California and U S EPA evaporative emission requirements Fuel lines that do not meet these requirements may not be used Order replacement hose through a Kohler Service Center Fuel System Tests When the engine starts hard or turns over but will not start it is possible that the problem is in the fuel system To find out if the fuel system is causing the problem perform the following tests Troubleshooting Fuel System Related Causes Test Conclusion 1 Check the following a Make sure the fuel tank contains clean fresh proper fuel Make sure the vent in fuel tank is open Make sure the fuel valve is open Make sure vacuum and fuel lines to fuel pump are secured and in good condition Check for fuel in the combustion chamber If there is fuel at the tip of the spark plug fuel is a Disconnect and ground spark plug leads reaching the combustion chamber b Close the choke on the carburetor c Crank the engine several times If there is no fuel at the tip of the spark plug d Remove the spark plug and check for fuel at check for fuel flow from the fuel tank Test 3 the tip Check for fuel flow from the tank to the fuel If fuel does flow from the line check for faulty pump fuel pump Test 4 a Remove the fuel line from the inlet fitting of fuel pump If fuel d
262. r motor Install fuel pump Install carburetor Install external governor controls Install throttle and choke controls Install Oil Sentry Install control panel if so equipped Install valve covers Install air cleaner assembly see Section 4 Install muffler Install oil filter and fill crankcase with oil Connect spark plug leads Install Flywheel End Oil Seal JT Make sure that the seal bore of the crankcase is clean and free of any nicks or burrs See Figure 11 1 Figure 11 1 Seal Bore of Crankcase 2 3 Apply a light coat of clean engine oil to the outside diameter of the oil seal Drive the oil seal into the crankcase using a seal driver Make sure the oil seal is installed straight and true in the bore and that the tool bottoms against the crankcase See Figure 11 2 Section 11 Reassembly Figure 11 2 Installing oil Seal Figure 11 4 Installing Governor Cross Shaft Hitch Pin 6 mm Shaft Install Governor Cross Shaft 1 Lubricate the governor cross shaft bearing surfaces in the crankcase with engine oil 2 Slide the small lower washer onto the governor cross shaft and install the cross shaft from the inside of the crankcase 3 6mm Governor Shaft Install the plain washer and then insert the hitch pin into the smaller lower hole of the governor cross shaft See Figures 11 3 and 11 4 8 mm Governor Shaft Install the nylon washer onto the governor cross shaft then start the pu
263. r oil to the F mark on the dipstick Always check the oil level with the dipstick before adding more oil Reinstall the oil fill cap and dipstick Start the engine and check for oil leaks Stop the engine correct any leaks and allow a minute for the oil to drain down then recheck the level on the dipstick 6 3 Section 6 Lubrication System Service Oil Cooler Some engines are equipped with an oil cooler One style of oil cooler mounts on the engine crankcase and has the oil filter on it The other style of oil cooler is mounted on the blower housing separate from the oil filter See Figure 6 7 Crankcase Mounted Oil Cooler Figure 6 7 Oil Coolers Inspect and clean the oil cooler every 100 hours of operation more frequently under severe conditions In order to be effective the oil cooler must be kept free of debris To service the crankcase mounted oil cooler clean off the outside fins with a brush or with compressed air To service the blower housing mounted oil cooler clean the outside of fins with a brush Remove the two screws holding the cooler unit to the blower housing Tilt the cooler downward Clean the inside of the cooler with a brush or with compressed air After cleaning reinstall the oil cooler to the blower housing with the two mounting screws 6 4 Oil Sentry General Some engines are equipped with an optional Oil Sentry switch This switch is designed to prevent the engine f
264. r the TPS or throttle shaft during procedure 2 Crankshaft movement rotation was detected by the speed sensor during procedure 3 Throttle plate position was out of learnable range recheck the 1500 RPM idle speed adjustment or 4 Problem with ECU or TPS 9 When the initialization procedure has been successfully completed turn off the key switch remove the jumper wire or connector and remove the rubber band from the throttle lever 10 Disconnect negative battery cable temporarily 5B to clear all learned adjustments Figure 5B 8 Service Connector Plug Metal Cased 11 Reconnect the battery cable and all external ECU Harness loads Readjust the idle speed to the equipment manufacturer s specified setting and recheck the high speed no load RPM setting Observe the overall performance TPS Initialization Procedure For 32 Pin MSE 1 1 Plastic Cased ECU Only Auto Learn Initialization 1 Check that the basic engine all sensors fuel fuel pressure and battery are good and functionally within specifications Important 2 Remove disconnect ALL external loads from the engine belts pumps electric PTO clutch Bae PD e a alternator rectifier regulator etc 3 Locate the service connector plug in the wiring harness To initiate the TPS auto learn function connect a jumper wire from the TPS initialization pin 24 violet wire to the battery voltage pin red wire or use the jumper plug wi
265. r throttle controls Faulty spark plugs Low compression Weak spark Fuel pump malfunction causing lack of fuel Engine overheated cooling air circulation restricted Quality of fuel Flywheel key sheared Intake system leak Engine Will Not Crank 1 Se Ste T9 PTO drive is engaged Battery is discharged Safety interlock switch is engaged Loose or faulty wires or connections Faulty key switch or ignition switch Faulty electric starter or solenoid Seized internal engine components Engine Runs But Misses 1 Vl e qe pecu i Dirt or water in the fuel system Spark plug lead disconnected Poor quality of fuel Faulty spark plug s Loose wires or connections that intermittently ground the ignition kill circuit Engine overheated Faulty ignition module or incorrect air gap Carburetor adjusted incorrectly SMART SPARK malfunction applicable models 3 1 Section 3 Troubleshooting Engine Will Not Idle 1 ph Ole S p DUI Dirt or water in the fuel system Stale fuel and or gum in carburetor Faulty spark plugs Fuel supply inadequate Idle speed adjusting screw improperly set Idle fuel adjusting needle improperly set some models Low compression Restricted fuel tank cap vent Engine overheated cooling system air circulation problem Engine Overheats 1 Soy Sloe IS Air intake grass screen cooling fins or cooling shrouds clogged Excessive engine load L
266. re 10 2 Removing Crankpin Plug Crankcase Inspection and Service Check all gasket surfaces to make sure they are free of gasket fragments Gasket surfaces must also be free of deep scratches or nicks Inspect the main bearing if so equipped for wear or damage refer to Section 1 Specifications Tolerances and Special Torque Values Replace the crankcase using a miniblock or short block as required Check the cylinder bore wall for scoring In severe cases unburned fuel can cause scuffing and scoring of the cylinder wall It washes the necessary lubricating oils off the piston and cylinder wall As raw fuel seeps down the cylinder wall the piston rings make metal to metal contact with the wall Scoring of the cylinder wall can also be caused by localized hot spots resulting from blocked cooling fins or from inadequate or contaminated lubrication If the cylinder bore is badly scored excessively worn tapered or out of round resizing is necessary Use an inside micrometer to determine the amount of wear refer to the Specifications Tolerances and Special Torque Values in Section 1 then select the nearest suitable oversize of either 0 25 mm 0 010 in or 0 50 mm 0 020 in Resizing to one of these oversizes will allow usage of the available oversize piston and ring assemblies First resize using a boring bar then use the following procedures for honing the cylinder NOTE Some CH25 26 engines feature POWER BORE
267. re removed 8 31 Section 8 Electrical System and Components Retaining Ring Installation k Position the retaining ring in the groove in one of the inner halves Assemble the other half over the top and slide on the outer collar Be certain the drive components are installed in correct sequence onto the armature shaft Slip the tool over the end of the armature shaft so the retaining ring inside is resting on the end of the shaft Hold the tool with one hand exerting slight pressure toward the starter Tap the top of the tool with a hammer until you feel the retaining ring snap into the groove Disassemble and remove the tool Squeeze the retaining ring with a pliers to compress it into the groove Assemble the inner halves with the larger cavity around the spring retainer See Figure 8 42 Slide the collar over them and thread the center screw in until resistance is felt Figure 8 42 Assembling Larger Inner Half Around Spring Retainer 6 7 Hold the base of the tool with a 1 1 8 wrench and turn the center screw clockwise with a 1 2 or 13 mm wrench to draw the spring retainer up around the retaining ring Stop turning when resistance increases Disassemble and remove tool Reinstall the dust cover Starter Disassembly 1 8 32 Remove the drive components following the instructions for servicing the drive Locate the small raised line on the edge of the drive end cap On starters with Style
268. rom starting in a low oil or no oil condition The Oil Sentry may not shut down a running engine before damage occurs In some applications this switch may activate a warning signal Read your equipment manuals for more information The pressure switch is designed to break contact as the oil pressure increases above 3 5 psi and make contact as the oil pressure decreases below 3 5 psi On stationary or unattended applications pumps generators etc the pressure switch can be used to ground the ignition module to stop the engine On vehicular applications lawn tractors mowers etc the pressure switch can only be used to activate a low oil warning light or signal NOTE Make sure the oil level is checked before each use and is maintained up to the F mark on the dipstick This includes engines equipped with Oil Sentry Installation The Oil Sentry pressure switch is installed in the breather cover See Figure 6 8 Oil Sentry r Switch s Breather Cover rd 4 Figure 6 8 Location of Oil Sentry Switch or pipe plug On engines not equipped with Oil Sentry the installation hole is sealed with a 1 8 27 N P T F pipe plug Section 6 Lubrication System To install the switch follow these steps 2 Gradually increase the pressure to the switch As 1 Apply pipe sealant with Teflon Loctite No the pressure increases through the range of 5924 or equivalent to the threads of the switch 3 0
269. rottle Linkage Governor Lever Connection 2 Check if the engine has a high speed throttle stop screw installed in the manifold casting boss See Figure 5B 38 High Speed Throttle Stop Screw Figure 5B 38 Throttle Details Figure 5B 39 Inserting Feeler Gauge Engines Without Stop Screw a Onengines without a stop screw pivot the throttle shaft and plate assembly into the Full Throttle position Insert a 1 52 mm 0 060 in feeler gauge between the rear tang of the throttle shaft plate and the underside of the manifold boss Use a locking pliers needle nose works best to temporarily clamp the parts in this position See Figure 5B 39 Feeler Gauge Section 5B EFI Fuel System B Setting the Initial Adjustment 1 Check the split where the clamping screw goes through the governor lever See Figure 5B 41 There should be a gap of at least 1 32 If the tips are touching and there is no gap present the lever should be replaced If not already installed position the governor lever on the cross shaft but leave the clamping screw loose b On engines with a stop screw pivot the throttle shaft and plate into the Full Throttle position so the tang of the throttle shaft plate is against the end of the high speed stop screw See Figure 5B 38 Temporarily clamp in this position Rotate the governor lever and shaft counterclockwise until it stops Use only enough pressure to hold it in that position
270. rted or worn see Figure 10 17 First Time Installation 10 7 N m 95 in Ib All Reinstallations 6 7 N m 60 in Ib 5 After torquing rotate the gear and check for freedom of movement Make sure there is no binding If binding occurs loosen the screws reposition the pump retorque the hex flange screws and recheck the movement LLLI MUN Piston Spring A Roll Pin Figure 10 17 Oil Pressure Relief Valve Piston and Spring Reassembly 1 Install the pressure relief valve piston and spring 2 Install the oil pickup to the oil pump body Lubricate the O Ring with oil and make sure it remains in the groove as the pickup is being installed 10 13 Section 10 Inspection and Reconditioning Governor Cross Shaft Oil Seal If the governor cross shaft seal is damaged and or leaks replace it using the following procedure Remove the oil seal from the crankcase and replace it with a new one Install the new seal to the depth shown in Figure 10 18 using a seal installer Governor Cross Shaft Seal 10 14 Section 11 Reassembly General NOTE Make sure the engine is assembled using all specified torque values tightening sequences and clearances Failure to observe specifications could cause severe engine wear or damage Always use new gaskets Apply a small amount of oil to the threads of critical fasteners before assembly unless a Sealant or Loctite is specified or preapplied Make sure a
271. s See Figure 4 12 To Service Every 250 hours of operation more often under extremely dusty or dirty conditions replace the paper element and check the inner element Follow these steps Removal 1 Remove the upper valve cover screws on each side securing the main bracket and loosen the hose clamp on the adapter inlet or remove the adapter mounting screws 1 Unhook the two retaining clips and remove the end cap from the air cleaner housing 2 Pullthe air cleaner element out of the housing 2 Lift the entire air cleaner assembly off the engine See Figure 4 13 Disassemble or service as required Installation Inner 1 Install the main mounting bracket with the center Element section up and the cutout around the carburetor Element aligning the mounting holes with the four upper valve cover holes 2 Install and torque the four valve cover mounting screws to specified torque value e esa e mms F dim E cala am cam z as E ai acumen m ras c Km Emi a pr Eu se ee T 3 Reconnect the hose to the adapter and tighten the clamp or install a new adapter gasket if the adapter was separated from the carburetor and torque the mounting fasteners to 7 3 N m Figure 4 13 Removing Elements 65 in Ib 3 After the element is removed check the condition NOTE Adapter configurations I MET of the inner element It should be replaced depending on engine and ap
272. s 3 and or 21 routed near noisy electrical signals coils spark plug lead plug connector 3 Engine Wiring Harness Related 24 Pin MSE 1 0 Plastic Cased ECU a b Pin circuits 9 and or 10 wiring or connectors Shielding for pin circuits 9 and or 10 damaged or not properly grounded Poor or improper grounds in system battery ECU oxygen sensor shielding fuel pump ignition output Pin circuits 9 and or 10 routed near noisy electrical signals coils spark plug lead plug connector 3 Engine Wiring Harness Related 32 Pin MSE 1 1 Plastic Cased ECU a b 5B 38 Pin circuits 9 and or 10 wiring or connectors Shielding for pin circuits 9 and or 10 damaged or not properly grounded Poor or improper grounds in system battery ECU oxygen sensor shielding fuel pump ignition output Pin circuits 9 and or 10 routed near noisy electrical signals coils spark plug lead plug connector 4 ECU Harness Related a ECU to harness connection problem 5 Ignition System Related a Non resistor spark plug s used Code 22 Source Throttle Position Sensor TPS Explanation Unrecognizable signal is being sent from sensor too high too low inconsistent Expected Engine Response A limp home operating mode occurs with an overall decrease in operating performance and efficiency Fuel delivery is based upon the oxygen sensor and five mapped values only Rich running black smo
273. s disassembled Check for buildup of dirt and debris on the crankcase cooling fins grass screen and other external surfaces Dirt or debris on these areas are causes of higher operating temperatures and overheating Check for obvious fuel and oil leaks and damaged components Excessive oil leakage can indicate a clogged or improperly assembled breather worn damaged seals and gaskets or loose or improperly torqued fasteners Check the air cleaner cover and base for damage or indications of improper fit and seal Check the air cleaner element Look for holes tears cracked or damaged sealing surfaces or other damage that could allow unfiltered air into the engine Also note if the element is dirty or clogged These could indicate that the engine has been under serviced Check the carburetor throat for dirt Dirt in the throat is further indication that the air cleaner is not functioning properly Check the oil level Note if the oil level is within the operating range on the dipstick or if it is low or overfilled e Check the condition of the oil Drain the oil into a container the oil should flow freely Check for metal chips and other foreign particles Sludge is a natural by product of combustion a small accumulation is normal Excessive sludge formation could indicate overrich carburetion weak ignition overextended oil change interval or wrong weight or type of oil was used to name a few NOTE Itis good pra
274. s the voltage drop to a specific temperature Using the fuel delivery maps the ECU then knows how much fuel is required for starting at that temperature Service The temperature sensor is a sealed non serviceable assembly A faulty sensor must be replaced If a blink code indicates a problem with the temperature sensor it can be tested as follows 1 Remove the oil temperature sensor from the adapter housing and cap or block the adapter hole 2 Wipe sensor clean and allow it to reach room temperature 20 C 68 F 3 Unplug the main harness connector from the ECU 4 With the sensor connected check the oil temperature sensor circuit resistance The value should be 2375 2625 Q See chart on pages 5B 28 5B 31 or 5B 32 35 Pin MA 1 7 Metal Cased ECU Check between the 14 and 27 pin terminals Section 5B EFI Fuel System 24 Pin MSE 1 0 Plastic Cased ECU Check The tip of the sensor protruding into the exhaust between the 6 and 4 pin terminals gas is hollow see cutaway Figure 5B 12 The outer portion of the tip is surrounded by the exhaust gas 32 Pin MSE 1 1 Plastic Cased ECU Check with the inner portion exposed to the ambient air between the 6 and 4 pin terminals When the oxygen concentration on one side of the tip is different than that of the other side a voltage signal 5 Unplug the sensor connector and check sensor typically cycling between 0 2 and 1 0 volt is generated resistance se
275. sh on retaining ring Hold the cross shaft up in position place a 0 50 mm 0 020 in feeler gauge on top of the nylon washer and push the retaining ring down the shaft to secure Remove the feeler gauge which will have established the proper end play See Figures 11 5 and 11 6 Figure 11 6 Setting Governor Cross Shaft End Play 8 mm Shaft Install Crankshaft 1 Carefully slide the flywheel end of the crankshaft through the main bearing in the crankcase See Figure 11 7 Figure 11 3 Installing 6 mm Governor Cross Shaft Section 11 Reassembly 2 Lubricate the cylinder bore piston and piston rings with engine oil Compress the rings of the 1 piston using a piston ring compressor 3 Lubricate the crankshaft journals and connecting rod bearing surfaces with engine oil 4 Make sure the Fly stamping on piston is facing towards the flywheel side of the engine Use a hammer with a rubber grip and gently tap the piston into the cylinder as shown in Figure 11 9 Be careful that the oil ring rails do not spring free between the bottom of the ring compressor and top of the cylinder Figure 11 7 Installing Crankshaft Install Connecting Rods with Pistons and Rings NOTE The cylinders are numbered on the crankcase Make sure to install the piston connecting rod and end cap into its appropriate cylinder bore as previously marked at disassembly Do not mix the end caps and connecting rods NOTE Proper orie
276. shes are away from the brush springs Section 8 Electrical System and Components NOTE Use a brush holder tool to keep the brushes 2 Insert the armature into the starter frame Make in the pockets A brush holder tool can easily sure the magnets are closer to the drive shaft end be made from thin sheet metal See Figure of armature The magnets will hold the armature 8 44 inside the frame Self Tapping Brush Springs 3 Install the drive end cap over the drive shaft Screw Brush Make sure the match marks on the end cap and Holder starter frame are aligned See Figure 8 45 Negative Negative Brush Stud Terminal with Positive Brushes Screw Figure 8 43 Style A Commutator End Cap with Brushes Brush Holder Tool Installed Figure 8 45 Starter Assembly Match Marks For Style A Commutator End Caps 4 Install the brush holder tool to keep the brushes in the pockets of the commutator end cap 5 Align the match marks on the commutator end cap and the starter frame Hold the drive end and the commutator end caps firmly to the starter Sheet Metal Brush lt frame Remove the brush holder tool Holder Tool For Style B Commutator End Caps Figure 8 44 Brush Holder Tool Style A End 4 If the brush assembly is not being replaced Cap position the brushes in their pockets in the carrier Move them to the retracted position and Style B End Cap Brush Replacement install car
277. spark plugs no maintenance or timing adjustments are necessary or possible Mechanical systems do occasionally fail or break down however so the following troubleshooting information is provided to help you get to the root of a reported problem A CAUTION High Energy Electric Spark The CD ignition systems produce a high energy electric spark but the spark must be discharged or damage to the system can result Do not crank or run an engine with a spark plug lead disconnected Always provide a path for the spark to discharge to ground Reported ignition problems are most often due to poor connections Before beginning the test procedure check all external wiring Be certain all ignition related wires are connected including the spark plug leads Be certain all terminal connections fit snugly Make sure the ignition switch is in the run position NOTE The CD ignition systems are sensitive to excessive load on the kill lead If a customer complains of hard starting low power or misfire under load it may be due to excessive draw on the kill circuit Perform the appropriate test procedure 8 5 Section 8 Electrical System and Components Test Procedure for Standard Fixed Timing CD Ignition System Isolate and verify the trouble is within the engine ignition system L Locate the plug connectors where the wiring harnesses from the engine and equipment are joined Separate the connectors and remove the white kill lead
278. ssure Tester DTI 019 Noid Light D T1 021 90 Adapter D T1 023 Oetiker Clamp Pliers DTI 025 Code Plug Red Wire DTI 027 Code Plug Blue Wire DTI 029 Flywheel Holding Tool CS Series SE Tools KLR 82407 ee SE Tools KLR 82408 To remove flywheel from engine 2 1 Section 2 Tools amp Aids Tools cont Flywheel Strap Wrench To hold flywheel during removal E ADEE LE Hydraulic Valve Lifter Tool To remove and install hydraulic lifters a Ignition System Tester For testing output on all systems except CD Kohler 25 455 01 S For testing output on capacitive discharge CD ignition system Kohler 24 455 02 S Offset Wrench K amp M Series To remove and reinstall cylinder barrel retaining nuts EE C orc itr dic a n Kohler 25 761 06 S To test and verify oil pressure Rectifier Regulator Tester 120 volt current Kohler 25 761 20 5 Rectifier Regulator Tester 240 volt current Kohler 25 761 41 5 Used to test rectifier regulators Individual Components Available Design Technology Inc CS PRO Regulator Test Harness D IT 031 Special Regulator Test Harness with Diode D T1 033 Spark Advance Module SAM Tester To test the SAM ASAM and DSAM on engines with SMART SPARK Bonuses Starter Brush Holding Tool Solenoid Shift SE Tools KLR 82416 To hold brushes during servicing Starter Retaining Ring Tool Inertia Drive To remove and reinstall drive retaining rings excluding FASCO starters Rocca a On hee Starter
279. stall the drive pinion dust cover spacer When power is applied to the starter the armature anti drift spring stop gear spacer and stop nut rotates As the armature rotates the drive pinion Torque the stop nut to 17 0 19 2 N m moves out on the splined drive shaft and into mesh 150 170 in Ib Reinstall the dust cover with the flywheel ring gear When the pinion reaches the end of the drive shaft it rotates the flywheel and Style A Style B cranks the engine Dust Cover N oust Cover i Retaining Ring 5 When the engine starts the flywheel rotates faster than the starter armature and drive pinion This amp Stop Nut Spring Retainer 3 moves the drive pinion out of mesh with the ring Stop Gear Spacer Anti Drift Spring B gear and into the retracted position When power is i Anti Drift Sprin removed from the starter the armature stops rotating 3 i and the drive pinion is held in the retracted position c Dust Cover PUSI Tover Spacer e by the anti drift spring Spacer Drive Pinion i Drive Pinion Starter Drive Service Drive Nut Collar C 35 Every 500 hours of operation or annually whichever occurs first clean and lubricate the splines on the starter drive shaft If the drive pinion is worn or has chipped or broken teeth it must be replaced See Figure 8 38 It is not necessary to completely disassemble the starter to service the drive components Style A
280. system This system delivers oil under pressure to the crankshaft camshaft and connecting rod bearing surfaces In addition to lubricating the bearing surfaces the lubrication system supplies oil to the hydraulic valve lifters A high efficiency gerotor pump is located in the closure plate The oil pump maintains high oil flow and oil pressure even at low speeds and high operating temperatures A pressure relief valve limits the maximum pressure of the system Service The closure plate must be removed to service the oil pickup the pressure relief valve and the oil pump Refer to the appropriate procedures in Sections 9 and 10 Oil Recommendations Using the proper type and weight of oil in the crankcase is extremely important so is checking oil daily and changing the oil and filter regularly Use high quality detergent oil of API American Petroleum Institute service class SG SH SJ or higher Select the viscosity based on the air temperature at the time of operation as shown in the following table RECOMMENDED SAE VISCOSITY GRADES 10W 30 E 10W ry TEMPERATURE RANGE EXPECTED BEFORE NEXT OIL CHANGE Use of synthetic oil having 5W 20 or 5W 30 rating is acceptable up to 4 C 40 F Synthetic oils will provide better starting in extreme cold below 23 C 10 F NOTE Using other than service class SG SH SJ or higher oil or extending oil change intervals longer than recommended can cause engine
281. t Parts Engine components can get extremely hot from operation To prevent severe burns do not touch these areas while the engine is running or immediately after it is turned off Never operate the engine with heat shields or guards removed 1 1 Section 1 Safety and General Information amp WARNING Explosive Fuel can cause fires and severe burns Do not fill the fuel tank while the engine is hot or running Explosive Fuel Gasoline is extremely flammable and its vapors can explode if ignited Store gasoline only in approved containers in well ventilated unoccupied buildings away from sparks or flames Do not fill the fuel tank while the engine is hot or running since spilled fuel could ignite if it comes in contact with hot parts or sparks from ignition Do not start the engine near spilled fuel Never use gasoline as a cleaning agent A WARNING Cleaning Solvents can cause severe injury or death Use only in well ventilated areas away from ignition sources Flammable Solvents Carburetor cleaners and solvents are extremely flammable Keep sparks flames and other sources of ignition away from the area Follow the cleaner manufacturer s warnings and instructions on its proper and safe use Never use gasoline as a cleaning agent 1 2 A WARNING Carbon Monoxide can cause severe nausea fainting or death Avoid inhaling exhaust fumes and never run the engine in a closed buildi
282. t and debris along with loose or damaged components NOTE Operating the engine with loose or damaged air cleaner components could allow unfiltered air into the engine causing premature wear and failure Air Cleaner Element 7 Precleaner a Figure 4 3 Removing Knob Style Cover Precleaner Service If so equipped wash and reoil the precleaner every 25 hours of operation more often under extremely dusty or dirty conditions To service the precleaner perform the following steps 1 Unhook the latches or loosen the retaining knob and remove the cover 2 Remove the foam precleaner from the paper air cleaner element 4 1 Section 4 Air Cleaner and Air Intake System 3 Wash the precleaner in warm water with detergent Rinse the precleaner thoroughly until all traces of detergent are eliminated Squeeze out excess water do not wring Allow the precleaner to air dry 4 Saturate the precleaner with new engine oil Squeeze out all excess oil 5 Reinstall the precleaner over the paper air cleaner element 6 Reinstall the air cleaner cover Secure the cover with the two latches or the retaining knob Element Cover Wing Nut Precleaner Figure 4 7 Removing Rubber Seal from Bracket Paper Element Service Standard Type Every 100 hours of operation more often under extremely dusty or dirty conditions replace the paper element Follow these steps 1 Unhook the latches or loosen
283. t functioning because the circuit is open shorted to ground or shorted to battery Expected Engine Response Engine will run very poorly with only one cylinder functioning Possible Causes 1 Injector Related a Injector coil shorted or opened 2 Engine Wiring Harness Related a Broken or shorted wire in harness ECU pin 14 to injector pin 2 ECU pin 28 to fuel pump relay pin 86 Note after key off then key on code 56 would be set also Fuel pump relay pin 87 to injector pin 1 b Open main fuse F1 3 Fuel Pump Relay Related a Bad fuel pump relay Primary side functional but pin 30 to pin 87 remains open Primary side pin 85 to pin 86 is either open or shorted during engine operation Note after key off then key on code 56 would be set also 4 ECU Related a Circuit controlling injector 1 damaged b Circuit controlling fuel pump relay damaged Code 52 32 Pin MSE 1 1 Plastic Cased ECU only Source Injector 2 circuit open shorted to ground or shorted to battery Explanation Injector 2 is not functioning because the circuit is open shorted to ground or shorted to battery Expected Engine Response Engine will run very poorly with only one cylinder functioning 5B 42 Possible Causes 1 Injector Related a Injector coil shorted or opened 2 Engine Wiring Harness Related a Broken or shorted wire in harness ECU pin 15 to injector pin 2 ECU pin 28 to fuel pump relay pin 86 Note aft
284. tance is not within the specified range unscrew the spark plug lead nut from the coil secondary tower and remove the plug lead Repeat step b 3 testing from the secondary tower terminal to the red primary terminal If resistance is now correct the coil is good but the spark plug lead is faulty replace the lead If step b 2 resistance was incorrect and or the secondary resistance is still incorrect the coil is faulty and needs to be replaced Spark Plugs EFI engines are equipped with Champion RC12YC Kohler Part No 12 132 02 S resistor style spark plugs Equivalent alternate brand plugs can also be used but must be a resistor style plug or permanent damage to the ECU will occur in addition to affecting operation Proper spark plug gap is 0 76 mm 0 030 in Wiring Harness The wiring harness used in the EFI system connects the electrical components providing current and ground paths for the system to operate All input and output signaling occurs through a special all weather connector that attaches and locks to the ECU see Figures 5B 23 5B 24 and 5B 25 Figure 5B 23 35 Pin MA 1 7 Metal Cased ECU Connector and O Ring Figure 5B 24 24 Pin MSE 1 0 Plastic Cased ECU Connector Figure 5B 25 32 Pin MSE 1 1 Plastic Cased ECU Connector The condition of the wiring connectors and terminal connections is essential to system function and performance Corrosion moisture and poor connecti
285. tart the engine If the starter is engaged while the flywheel is rotating the starter pinion and flywheel ring gear may clash resulting in damage to the starter Troubleshooting Guide Starting Difficulties Battery 1 Check the specific gravity of battery If low recharge or replace battery as necessary Starter 1 Clean corroded connections and tighten loose connections Does Not 2 Replace wires in poor condition and with frayed or broken Energize insulation Starter Switch 1 By pass the switch or solenoid with a jumper wire If starter or Solenoid cranks normally replace the faulty components Solenoid Shift Starters Perform individual solenoid test procedure See pages 8 44 and 8 45 Batt 1 Check the specific gravity of battery If low recharge or replace d battery as necessary 1 Check for excessively dirty or worn brushes and commutator Starter Clean using a coarse cloth not emery cloth Energizes 2 Replace brushes if excessively or unevenly worn but Turns Slowly 1 Make sure the clutch or transmission is disengaged or placed in neutral This is especially important on equipment with Transmission hydrostatic drive The transmission must be exactly in neutral to or prevent resistance which could keep the engine from starting Engine 2 Check for seized engine components such as the bearings connecting rod and piston 8 29 Section 8 Electrical System and Components Operation Inertia Drive Starters 7 In
286. te Shim NOTE The cylinders are numbered on the l crankcase Use the numbers to mark each Remove Connecting Rods with Pistons end cap connecting rod and piston for and Rings reassembly Do not mix end caps and 1 Remove the two hex flange screws securing the connecting rods closest connecting rod end cap Remove the end cap See Figure 9 70 Figure 9 72 Removing Piston Connecting Rod Assemblies Pure O REMOVING CONNEC NNG AOA Bol 2 Carefully remove the connecting rod and piston NOTE Ifa carbon ridge is present at the top of assembly from the cylinder bore See Figure 9 72 either cylinder bore use a ridge reamer tool to remove the ridge before attempting to remove the piston 3 Repeat the above procedures for the other connecting rod and piston assembly 9 18 Section 9 Disassembly Remove Crankshaft 1 Carefully pull the crankshaft from the crankcase See Figure 9 73 Note thrust washers and shims if used Figure 9 75 Removing Governor Cross Shaft Retainer 8 mm Shaft Design 2 Pull the cross shaft with small washer out 7 through the inside of the crankcase See Figure Figure 9 73 Removing Crankshaft 9 76 Remove Governor Cross Shaft 1 Remove the hitch pin and plain washer or the retainer and nylon washer from the governor cross shaft See Figures 9 74 and 9 75 Figure 9 76 Pulling Governor Cross Shaft Remove Flywheel End Oil Seal IS 1 Remove oil seal from crankcase See Fig
287. te the clamp bracket until the end of the screw contacts the stop Insert a 0 025 mm 0 001 in feeler gauge between the carburetor housing and the side of the clamp bracket to set the endplay then tighten the mounting screw securely See Figure 5A 10 Section 5A LPG Fuel Systems 3 Insert a 0 025 mm 0 001 in feeler gauge between the side of the stop collar and the carburetor housing then check or set the position of the stop collar The head of the mounting screw must be in contact with the carburetor boss from the back hose fitting side preventing any further rotation over center Set or adjust the stop collar as required See Figure 5A 12 Figure 5A 10 Tightening Idle Speed Clamp Mounting Screw High Speed Stop Collar 4 Reset the idle speed adjustment screw back to the original position High Speed Stop Collar Position 1 Make sure the idle speed clamp position has already been checked or properly set Figure 5A 12 Adjusting Setting Stop Collar 2 Rotate and hold the throttle shaft so the throttle plate is fully open perfectly vertical See Figure 5A 11 4 Tighten the screw securely NOTE After the idle speed clamp bracket and the high speed stop collar positions have been set check that the throttle shaft pivots freely without binding or restriction Throttle Linkage Clamp Bracket Position Carburetor must be assembled to engine with linkage attached to set this position 1 The throttle
288. terminals 32 Pin MSE 1 1 Plastic Cased ECU 9 and 10 pin terminals See pages 5B 28 5B 33 according to ECU style A resistance value of 750 1000 Q at room temperature 20 C 68 F should be obtained If resistance is correct check the mounting air gap toothed ring gear damage runout etc and flywheel key 6 Disconnect the speed sensor connector from wiring harness It is the connector with one heavy black lead see Figure 5B 5 Viewing the connector as shown dual aligning rails on top test the resistance between the terminals indicated A reading of 750 1000 should again be obtained Dual Aligning Rails Corresponds To 21 Metal Cased ECU or 49 Plastic Casec ECU In Main 10 Plastic Cased Connector ECU In Main Connector Test Terminals Figure 5B 5 Speed Sensor Connector 7 a Ifthe resistance is incorrect remove the screw securing the sensor to the mounting bracket and replace the sensor b If the resistance in step 5 was incorrect but the resistance of the sensor alone was correct test the main harness circuits between the sensor connector terminals and the corresponding pin terminals in the main connector Correct any observed problem reconnect the sensor and perform step 5 again Section 5B EFI Fuel System Throttle Position Sensor TPS Mounted on the throttle body intake manifold and operated directly off the end of the throttle shaft the TPS works as a pot
289. ters into their appropriate location in the crankcase Do not use a magnet See Figure 11 35 Figure 11 32 Installing Supports for Metal Grass Screen NOTE Hydraulic lifters should always be installed in the same position as before 2 Tighten the supports with a torque wrench to disassembly The exhaust lifters are 9 9 N m 88 in Ib See Figure 11 33 The grass located on the output shaft side of screen will be installed to the supports after the the engine while the intake lifters are blower housing is in place located on the fan side of the engine The cylinder numbers are embossed on the top of the crankcase and each cylinder head See Figure 11 36 Figure 11 33 Torquing Supports for Metal Screen Some Models Install Hydraulic Lifters 1 See Servicing Hydraulic Lifters in Section 10 for lifter preparation bleed down procedures Figure 11 35 Installing Hydraulic Lifters 2 Apply camshatt lubricant see Section 2 to the bottom surface of each lifter See Figure 11 34 Lubricate the hydraulic lifters and the lifter bores in the crankcase with engine oil 11 10 Figure 11 36 Match Numbers on Cylinder Barrel and Head Figure 11 37 Intake Valve Seal Location Valve Stem Seals These engines use valve stem seals on the intake valves and occasionally on the exhaust valves Always use a new seal whenever the valve is removed or if the seal is deteriorated or damaged in any way Never reuse an old sea
290. th integral spacers 6 2 N m 55 in Ib Figure 11 89 Valve Cover Fastener Torque Sequence NOTE Fastener 2 may secure fuel pump bracket on earlier models Figure 11 90 Tightening Valve Cover Screws Install Air Cleaner Assembly Refer to Section 4 for air cleaner reassembly procedure Standard Air Cleaner 1 Attach the rubber breather hose to the breather cover Connect the fuel inlet line to the carburetor and secure with a clamp See Figure 11 91 11 27 Section 11 Reassembly 3 Secure the air cleaner base and bracket using the hex flange screws Position the bracket with the hole toward the breather hose Be careful not to drop screws into the carburetor If a rear air cleaner bracket is used install the two M5 screws through the rear of the base Torque the three M6 screws to 6 2 7 3 N m 55 65 in Ib and the two rear M5 mounting screws when applicable to 4 0 N m 35 in Ib See Figures 11 94 and 11 95 Figure 11 91 Connecting Fuel Inlet Line 2 Position a new gasket and the air cleaner base while carefully pulling the loose end of the rubber breather hose through the base until properly seated collars sealed against each side of base See Figure 11 92 Figure 11 92 Pulling Breather Hose through Base NOTE Route the fuel line in the contour as shown in Figure 11 93 to avoid restriction Figure 11 95 Tightening Rear Base Bracket Screws Some Models 4 Instal
291. th the blue jumper wire If using the PC based diagnostic tool and software see Section 2 go to Special Tests and follow the prompts to complete 8 Hold throttle against idle speed stop screw turn the ignition switch to on position do not start engine and observe the Malfunction Indicator Light MIL a The light should blink on off quickly for approximately 3 seconds and then go off and stay off indicating the initialization procedure has been successful 4 Start the engine and immediately observe the Malfunction Indicator Light MIL The light should start blinking 4 consecutive times every 2 seconds 5B 9 Section 5B EFI Fuel System Remove the jumper wire or plug from the service connector plug in wiring harness Run the engine at full throttle above 3000 RPM to warm up the engine and initiate O sensor function in closed loop operation Watch the MIL When the light starts blinking rapidly 5 blinks per second move the throttle lever to the low idle speed position Check and adjust the idle speed to 1500 RPM using a tachometer The lamp should continue to blink rapidly for another 30 seconds before switching to a slow blink When the MIL blinks slowly do not do anything but wait until the MIL shuts off This indicates that this procedure has been completed successfully Shut off the engine If the learn procedure was successfully completed the external loads removed
292. that EFI related problems are more often caused by the wiring harness or connections than by the EFI components Even small amounts of corrosion or oxidation on the terminals can interfere with the milliamp currents used in system operation Cleaning the connectors and grounds will solve problems in many cases In an emergency situation simply disconnecting and reconnecting the connectors may clean up the contacts enough to restore operation at least temporarily Section 5B EFI Fuel System If a fault code indicates a problem with an electrical component disconnect the ECU connector and test for continuity between the component connector terminals and the corresponding terminals in the ECU connector using an ohmmeter Little or no resistance should be measured indicating that the wiring of that particular circuit is OK An illustrated listing of numerical terminal locations for each style of ECU connector is provided on pages 5B 28 5B 31 or 5B 32 5B 28 for 35 Pin MA 1 7 Metal Cased ECU 5B 31 for 24 Pin MSE 1 0 Plastic Cased ECU 5B 32 for 32 Pin MSE 1 1 Plastic Cased ECU NOTE When performing voltage or continuity tests avoid putting excessive pressure on or against the connector pins Flat pin probes are recommended for testing to avoid spreading or bending the terminals 5B 27 Section 5B EFI Fuel System 35 Pin MA 1 7 Metal Cased ECU Systems Pug Component Ignition Coil 1 Not used Engi
293. the charge pump capacitor voltage the later the trigger pulse will occur retarding the timing accordingly Troubleshooting CD Ignition Systems The CD ignition systems are designed to be trouble free for the life of the engine Other than periodically checking replacing the spark plugs no maintenance or timing adjustments are necessary or possible Mechanical systems do occasionally fail or break down however so the following troubleshooting information is provided to help you get to the root of a reported problem A CAUTION High Energy Electric Spark The CD ignition systems produce a high energy electric spark but the spark must be discharged or damage to the system can result Do not crank or run an engine with a spark plug lead disconnected Always provide a path for the spark to discharge to ground Reported ignition problems are most often due to poor connections Before beginning the test procedure check all external wiring Be certain all ignition related wires are connected including the spark plug leads Be certain all terminal connections fit snugly Make sure the ignition switch is in the run position 8 8 NOTE The CD ignition systems are sensitive to excessive load on the kill lead If a customer complains of hard starting low power or misfire under load it may be due to excessive draw on the kill circuit Perform the appropriate test procedure Test Procedure for SMART SPARK Ignition Systems The follo
294. the element cover 3 Remove the element cover the air cleaner element with precleaner and the stud seal y k Li 3 Figure 9 10 Removing Breather Tube from Base 9 3 Section 9 Disassembly Figure 9 11 Removing Tube from Breather Cover 6 Remove the rubber breather tube from the breather cover See Figure 9 11 Heavy Duty Air Cleaner 1 Disconnect the breather hose from the fitting in adapter or elbow 2 Remove the two screws one barrel carburetor models or the four hex flange nuts two barrel carburetor models securing the adapter or elbow See Figure 9 12 Breather l Nuts Figure 9 12 Breather Hose Mounting Nuts and Adapter Elbow Two Barrel Model Pictured 3 Remove the screws securing the main support bracket for air cleaner to the valve covers On two barrel carburetor models remove the two mounting screws into the top of intake manifold Unhook the choke return spring if equipped Do not lose any of the hardware See Figure 9 13 9 4 Mounting Screws Figure 9 13 Air Cleaner Bracket Mounting Screws Two Barrel Model Pictured 4 Remove the heavy duty air cleaner as an assembly from the engine See Figure 9 14 Figure 9 14 Removing Heavy Duty Air Cleaner Assembly Two Barrel Model Pictured Remove Fuel Pump A WARNING Explosive Fuel Gasoline is extremely flammable and its vapors can explode if ignited Store gasoline only in approved containers in
295. the intake manifold assembly The manifold consists of a one piece aluminum casting which also provides mounting for the fuel injectors throttle position sensor fuel rail air baffle idle speed screw and air cleaner assembly Service The throttle body intake manifold is serviced as an assembly with the throttle shaft throttle plates and idle speed adjusting screw installed The throttle shaft rotates on needle bearings non serviceable capped with rubber seals to prevent air leaks Idle Speed Adjustment RPM General The idle speed is the only adjustment that may be performed on the EFI system The standard idle speed setting for EFI engines is 1500 RPM but certain applications might require a different setting Check the equipment manufacturer s recommendation Section 5B EFI Fuel System For starting and warm up the ECU will adjust the fuel and ignition timing based upon ambient temperature engine temperature and loads present In cold conditions the idle speed will probably be higher than normal for a few moments Under other conditions the idle speed may actually start lower than normal but gradually increase to the established setting as operation continues Do not attempt to circumvent this warm up period or readjust the idle speed during this time The engine must be completely warmed up for accurate idle speed adjustment Adjustment Procedure 1 Make sure there are no fault codes present in the ECU memory
296. the regulating pin against the cross shaft tends to close the throttle plate The governor spring tension and the force applied by the regulating pin balance each other during operation to maintain engine speed Section 5 Fuel System and Governor e When load is applied and the engine speed and governor gear speed decreases the governor spring tension moves the governor arm to open the throttle plate wider This allows more fuel into the engine increasing the engine speed As the speed reaches the governed setting the governor spring tension and the force applied by the regulating pin will again offset each other to hold a steady engine speed Adjustments NOTE Do not tamper with the governor setting Overspeed is hazardous and could cause personal injury General The governed speed setting is determined by the position of the throttle control It can be variable or constant depending on the engine application Initial Adjustment NOTE EFI engines require a special initial adjustment procedure which is covered in subsection 5B Refer to Initial Governor Adjustment in that section for setting the governor on EFl equipped engines Procedure Carburetor Equipped Engines Make this adjustment whenever the governor arm is loosened or removed from the cross shaft See Figure 5 38 and adjust as follows 1 Make sure the throttle linkage is connected to the governor arm and the throttle lever on the carburetor
297. the removal tool Anti Drift until you feel resistance Use a wrench 1 1 8 or Spring adjustable to hold the base of the removal tool fe Use another wrench or socket 1 2 or 13 mm to turn the center screw clockwise see Figure 8 41 The resistance against the center screw will tell Dust Cover Spacer OG Drive the groove in the armature shaft Pinion p you when the retaining ring has popped out of Drive vut C Collar Figure 8 39 Drive Components Bonded Inertia Drive Starter 2 Disassemble the snap ring removal tool see Section 2 7 3 Again referring to Figure 8 39 grasp the spring retainer and push it toward the starter Figure 8 41 Holding Tool and Turning Center compressing the anti drift spring and exposing Screw Clockwise to Remove Retaining Ring the retaining ring 6 Remove the drive components from the armature 4 Holding the spring retainer in the retracted shaft paying attention to the sequence If the position assemble the inner halves of the removal splines are dirty clean them with solvent tool around the armature shaft with the retaining ring in the inner groove see Figure 8 40 Slide 7 The splines should have a light film of lubricant the collar over the inner halves to hold them in Relubricate as necessary with Kohler bendix position starter lubricant see Section 2 Reinstall or replace the drive components assembling them in the reverse order they we
298. the retaining knob and remove the cover AUR MEN i NF 2 Remove the wing nut element cover and paper element with precleaner if so equipped D et 1 Cr E Z P sa pe 5 Yue 4 m ne E E wm er cl Mir ee a ip n ie d 3 Remove the precleaner if so equipped from the paper element Service the precleaner as described in Precleaner Service Figure 4 5 Removing Element Cover Wing Nut 4 Do not wash the paper element or use pressurized air as this will damage the element Replace a dirty bent or damaged element with a genuine Kohler element Handle new elements carefully do not use if the sealing surfaces are bent or damaged 4 2 Section 4 Air Cleaner and Air Intake System 5 Check the seal for any damage or deterioration 7 Reinstall the air cleaner cover and secure with the Replace as necessary See Figure 4 7 latches or the retaining knob 6 Reinstall the seal paper element precleaner NOTE Make sure the correct depth air cleaner element cover and wing nut element and rubber seal are used for the engine spec involved Some engines use a deeper or extra capacity air cleaner and a longer rubber seal Cover Knob Cover Knob Air Cleaner Gasket Cover N Air Cleaner Latch Cover Spring Lever 5 Latch f Nut Latch Lever u p Pin CES Precleaner Element Air Cleaner X Element Air Cleaner Bracket E danaa Air Cleaner Base Gask
299. this manner the pressure within the primary chamber is The vacuum lock off mechanism is located in the maintained at a relatively constant 29 kPa 4 psi secondary chamber When the engine is running manifold vacuum above the diaphragm 17 draws it up so the secondary valve can function normally When the engine is stopped manifold vacuum is terminated and the diaphragm relaxes and pushes down on the secondary valve lever preventing any fuel flow or leakage through the regulator From Primary To Intake Ms uid Manifold To Secondary Chamber 1 Primary Valve 6 Contact Button 2 Primary Valve Seat 7 Primary Valve Lever 3 Primary Chamber 8 Primary Lever Spring 4 Primary Diaphragm 9 Primary Pressure 5 Primary Diaphragm Spring Adjustment Figure 5A 21 Primary Chamber 11 Secondary Valve 16 Secondary Valve Lever 12 Secondary Valve Seat 17 Vacuum Lock Off 13 Secondary Chamber Diaphragm 14 Secondary Diaphragm 18 Idle Adjust Screw 15 Secondary Diaphragm Spring 19 Balance Spring Figure 5A 22 Secondary Chamber 5A 11 Section 5A LPG Fuel Systems Preventative Maintenance The regulator is preset at the factory and generally requires no further adjustment No periodic service is required Over time depending on fuel quality operating environment and system performance fuel deposits can accumulate inside the regulator Those regulators containing a drain plug Nikki should be drained every 500 hours to
300. tion Do not allow the alligator clip leads to touch each other Figure 8 11 8 12 Figure 8 12 2 Check the SAM part number stamped on the side of the housing Verify that you have an analog SAM ASAM Part No 24 584 10 or lower not a digital SAM DSAM Part No 24 584 18 and higher Follow sub step a for testing an ASAM with this tester Digital SAM DSAM modules require Tester 25 761 40 5 for proper testing a Depress the tester button and hold it down After approximately four seconds a numerical sequence should be displayed beginning with 1 or 2 and continuing to 8 or 9 followed by a letter P pass or F fail See Figures 8 11 and 8 12 DO NOT release the tester button until the test cycle completes and the display goes off If you get a sign instead of the numerical sequence and or an F at the end of the cycle the SAM is probably bad Recheck all of the connections check the condition of the tester battery and repeat the test If you get the sign and or F again in the retest replace that SAM IMPORTANT Allow 15 20 seconds for the tester to clear and reset itself between tests or if test is interrupted before completion of test cycle Otherwise a false reading may be displayed in the form of a or a faint 8 3 Disconnect the yellow and brown tester leads from the long module leads Connect the brown tester lead to the short brown module lead Connect the yellow tester lea
301. tion Voltage Safety Switch Throttle Position Sensor TPS and Temperature Sensor Ground Not Used Oil Temperature Sensor Input Not Used Throttle Position Sensor TPS Input Speed Sensor Input Speed Sensor Ground Oxygen Sensor Input Not Used Oxygen Sensor Ground if needed Diagnostic Line Throttle Position Supply Voltage Battery Ground Injector 1 Output Injector 2 Output Main Relay Output Malfunction Indicator Light MIL Not Used Tach Output if needed Not Used Ignition Coil 1 Output Ignition Coil 2 Output TPS Initialization Terminal o0O 00 goo 00 0c Oo o0o0 000000000 5B 31 Section 5B EFI Fuel System 32 Pin MSE 1 1 Plastic Cased ECU Systems Pin Function Permanent Battery Voltage Switched Battery Voltage TPS Set Auto Learn Initialization Terminal Throttle Position Sensor TPS and Temperature Sensor Ground Not Used Oil Temperature Sensor Input Not Used Throttle Position Sensor TPS Input Speed Sensor Input Speed Sensor Ground Not Used Not Used Not Used Injector 1 Output Injector 2 Output Not Used Diagnostic Line Throttle Position Sensor Supply Voltage Battery Ground Oxygen Sensor Input Battery Ground Secondary Not Used Not Used Not Used Safety Switch Input Not Used Not Used Main Relay Output Malfunction Indicator Light MIL Ignition Coil 1 Output Ignition Coil 2 Output Not Used 9B 32 co co N O a A WO N O00 00 0O 0000000000 0o0 0oO0 0 00 00000000 0 SEE
302. tive Discharge CD coil Figure 8 3 This is a basic ignition system that uses a fixed ignition module where the ignition timing and spark remains constant regardless of the engine speed The Electronic Spark Advance Smart Spark System utilizes a Capacitive Discharge CD coil Figure 8 6 This system uses an analog ASAM or a digital DSAM spark advance module that triggers the ignition modules and spark The ignition timing varies depending upon the engine speed with this system The Digital Spark Advance Ignition DSAI System Figure 8 17 This system uses a digital microprocessor which is located in the ignition modules The ignition timing varies depending upon the engine speed with this system A Capacitive Discharge with Fixed Timing This system Figure 8 3 consists of the following components e A magnet assembly which is permanently affixed to the flywheel e Two electronic capacitive discharge ignition modules which mount on the engine crankcase Figure 8 4 e Akill switch or key switch which grounds the modules to stop the engine e Two spark plugs Ignition Starter and a Module Carburetor Pressure Advance Input Solenoid Module Input i Optional Oil Pressure EN B and ji Carburetor Spark Plugs Ignition Modules Safety Input Rectifier Regulator Figure 8 3 Electronic CD Ignition System For Customer Connected Tractor Applications 8 4 Kill Switch or Off Position of Key
303. to clean or check condition as required See Figure 5A 6 Replace with a new Kohler high pressure hose LP rated if the condition is questionable in any way Secure new hose using new clamps Figure 5A 6 5 Clean all parts as required use a good carburetor cleaner following the manufacturer s instructions Blow clean compressed air through all the passages Do not poke or probe into the load block assembly as damage can be done resulting in serious operational problems See Figure 5A 7 Figure 5A 7 Section 5A LPG Fuel Systems Nikki Carburetor 1 Turn off fuel supply at tank 2 Remove the air cleaner breather hose fuel line vacuum hose choke and throttle linkages Remove the nuts carburetor and gaskets from the engine Discard the gaskets Remove the fuel transfer chamber cover by removing the three screws See Figure 5A 3 Carefully remove the cover and gasket Discard the gasket The main jet is fixed and nonadjustable but may be accessed for cleaning by removing the rear plug and sealing washer Discard the washer In order to clean the off idle transfer passages and carburetor thoroughly use a good carburetor cleaner and follow the manufacturer s instructions Blow clean compressed air through the passages and make sure all are open before reassembling Do not use wire or metal objects to clean passages or carburetor body LPG Carburetor Inspection 1 Inspect the carburetor bo
304. ton staples to retain them See Figure Starters with Style B end caps have the brushes 8 46 in a plastic carrier housing separate from the end cap Replacement brushes come preassembled in the 5 Align the terminal stud block with the notch carrier housing retained with two carton staples in the starter frame and slide the brush carrier assembly into the frame The commutator will Commutator Service push the carton staples out as the brush assembly Clean the commutator with a coarse lint free cloth Do is installed Position the end cap over the brush not use emery cloth assembly so the holes for the thru bolts are aligned with those in the brush carrier If the commutator is badly worn or grooved turn it down on a lathe or replace the armature Starter Reassembly 1 Place the thrust washer if so equipped over the drive shaft of the armature 8 33 Section 8 Electrical System and Components Figure 8 46 Style B Commutator End Cap with Brushes 6 Install the thru bolts and tighten securely 7 Lubricate the drive shaft with Kohler bendix starter drive lubricant see Section 2 Install the drive components following the instructions for servicing the starter drive Starter Assembly Armature Figure 8 47 Nippondenso Solenoid Shift Starter 8 34 Solenoid Shift Electric Starters The following subsection covers the solenoid shift electric starters Much of the information in the proceeding subsection
305. tric fuel pump is used to move fuel from the tank through the fuel line and in line fuel filter A Section 5B EFI Fuel System fuel pressure regulator maintains a system operating pressure of 39 psi and returns any excess fuel to the tank At the engine fuel is fed through the fuel rail and into the injectors which inject it into the intake ports The ECU controls the amount of fuel by varying the length of time that the injectors are on This can range from 1 5 8 0 milliseconds depending on fuel requirements The controlled injection of the fuel occurs each crankshaft revolution or twice for each 4 stroke cycle One half the total amount of fuel needed for one firing of a cylinder is injected during each injection When the intake valve opens the fuel air mixture is drawn into the combustion chamber ignited and burned The ECU controls the amount of fuel injected and the ignition timing by monitoring the primary sensor signals for engine temperature speed RPM and throttle position load These primary signals are compared to preprogrammed maps in the ECU computer chip and the ECU adjusts the fuel delivery to match the mapped values An oxygen sensor provides continual feedback to the ECU based upon the amount of unused oxygen in the exhaust indicating whether the fuel mixture being delivered is rich or lean Based upon this feedback the ECU further adjusts fuel input to reestablish the ideal air fuel ratio This operating
306. ts Air escaping from crankcase DreatliGg euo eser tieo tont EH Rhea tob ved ie euEs Defective rings or worn cylinder Air escaping from exhaust SYSEOHIE auuuciededi eios imd Poder rsesx i ct bn ovis dS Defective exhaust valve improper seating Alr CSCa Wi irom Car OU CLOW osudena Det dH ADR USE Defective intake valve improper seating Gauge reading in low green Zone scsi oenidcri eredi badsolt tr vend ted Piston rings and cylinder in good condition Gauge reading in moderate yellow zone eese Engine is still usable but there is some wear present Customer should start planning for overhaul or replacement Gauge reading in high red zone x vnsssisauesosiansaucanseosnesnnosevenesacssvneseescousones Rings and or cylinder have considerable wear Engine should be reconditioned or replaced 3 5 Section 3 Troubleshooting 3 6 Section 4 Air Cleaner and Air Intake System Air Cleaners General Most engines are equipped with a replaceable high density paper air cleaner element surrounded by an oiled foam precleaner and housed under a flat outer cover This is typically referred to as the standard air cleaner assembly See Figures 4 1 and 4 4 Some engines utilize a heavy duty style air cleaner as shown in Figure 4 12 Figure 4 1 Standard Air Cleaner Standard Air Cleaner Service Check the air cleaner daily or before starting the engine Check for and correct any buildup of dir
307. ture is bad 4 Check the armature windings insulation for shorting Shift Fork Check that the shift fork is complete and the pivot and contact areas are not excessively worn cracked or broken 8 39 Section 8 Electrical System and Components Brush Replacement Starter Service The brushes and springs are serviced as a set 4 Use Clean the drive lever and armature shaft Apply Brush and Spring Kit Kohler Part No 25 221 01 S if Kohler electric starter drive lubricant see Section 2 replacement is necessary Versilube G322L or Mobil Temp SHC 32 to the lever and shaft Clean and check the other starter parts for 1 Perform steps 1 5 in Starter Disassembly wear or damage as required 2 Remove the two screws securing the brush Starter Reassembly holder assembly to the end cap plate Note the orientation for reassembly later See Figure 8 63 Discard the old brush holder assembly 1 Apply drive lubricant see Section 2 to the armature shaft splines Install the drive pinion onto the armature shaft 2 Install and assemble the stop collar retainer assembly a Install the stop collar down onto the armature shaft with the counter bore recess up b Install a new retainer in the larger rear groove of the armature shaft Squeeze with a pliers to compress it in the groove c Slide the stop collar up and lock it into place so the recess surrounds the retainer in the groove If necessary rotate the pinion o
308. ty information This manual contains safety precautions which are explained below Please read carefully FN WARNING Warning is used to indicate the presence of a hazard that can cause severe personal injury death or substantial property damage if the warning is ignored A CAUTION Caution is used to indicate the presence of a hazard that will or can cause minor personal injury or property damage if the caution is ignored NOTE Note is used to notify people of installation operation or maintenance information that is important but not hazard related For Your Safety These precautions should be followed at all times Failure to follow these precautions could result in injury to yourself and others Accidental Starts can cause severe injury or death Disconnect and ground spark plug leads before servicing Accidental Starts Disabling engine Accidental starting can cause severe injury or death Before working on the engine or equipment disable the engine as follows 1 Disconnect the spark plug lead s 2 Disconnect negative battery cable from battery Rotating Parts can cause severe injury Stay away while engine is in operation Rotating Parts Keep hands feet hair and clothing away from all moving parts to prevent injury Never operate the engine with covers shrouds or guards removed Hot Parts can cause severe burns Do not touch engine while operating or just after stopping Ho
309. ugh the clearance between between the secondary valve 11 and the valve seat the primary valve 1 and valve seat 2 As fuel 12 While the engine is operating and fuel is being continues to flow and the primary chamber drawn from the secondary chamber the secondary approaches 29 kPa 4 psi the primary diaphragm 4 diaphragm 14 is raised by atmospheric pressure overcomes the tension of the diaphragm spring 5 As simultaneously lifting the secondary valve lever 16 the diaphragm 4 and contact button 6 move up the opening the secondary valve 11 allowing fuel to primary lever spring 8 pushes the primary lever 7 flow When the engine is running at idle there may up in turn closing the primary valve 1 and stopping not be enough vacuum created in the carburetor the flow of fuel As fuel is consumed and the pressure venturi to overcome the tension of the secondary in the primary chamber drops below 29 kPa 4 psi the diaphragm spring 15 and the secondary diaphragm diaphragm spring 5 tension will be greater than the cannot open the valve Under those conditions the fuel pressure causing the primary diaphragm 4 to be idle adjusting screw 18 and balance spring 19 are pushed down This causes the contact button 6 to used to apply just enough pressure on the diaphragm push the primary lever 7 down in turn opening the 14 to maintain sufficient fuel flow for idle operation primary valve 1 and admitting more fuel In
310. ull range of throttle plate movement will not be achieved if the DLA is partially extended when assembled Loosen the two DLA mounting plate screws located on the top of the actuator plate With the throttle linkage centered in the U Clip or secured with a retaining clip at the end of the DLA shaft slide the DLA bracket assembly back until the throttle plate is fully open Torque the mounting plate screws to 2 5 N m 22 in Ib Troubleshooting Procedure Engine does not run at the expected speed Engine starts but will not continue to run 1 Check to see that the throttle linkage and DLA 1 Check the linkage connection between the DLA have full range of motion having no mechanical and throttle plate interference 2 Verify the DLA initializes when power is 2 Test the potentiometer wiper voltage if supplied key switch in the start or run position equipped 3 Test the potentiometer wiper output voltage if 3 Test the SPST switch if equipped equipped 4 Test the SPST switch if equipped 5 Check the wire harness and connections 5 24 Section 5A LPG Fuel Systems A WARNING Explosive Fuel LPG is extremely flammable is heavier than air and tends to settle in low areas where a spark or flame could ignite the gas Do not start or operate this engine in a poorly ventilated area where leaking gas could accumulate and endanger the safety of persons in the area require special licensing or certification for LPG repair sho
311. ure 9 77 er i I LUA Figure 9 74 Removing Governor Cross Shaft Hitch Pin 6 mm Shaft Design Figure 9 77 Removing Oil Seal 9 19 Section 9 Disassembly 9 20 Section 10 Inspection and Reconditioning This section covers the operation inspection and repair reconditioning of major internal engine components The following components are not covered in this section They are covered in sections of their own Air Cleaner Section 4 Carburetor amp External Governor Section 5 Ignition Charging amp Electric Starter Section 8 Clean all parts thoroughly Only clean parts can be accurately inspected and gauged for wear or damage There are many commercially available cleaners that will quickly remove grease oil and grime from engine parts When such a cleaner is used follow the manufacturer s instructions and safety precautions carefully Make sure all traces of the cleaner are removed before the engine is reassembled and placed into operation Even small amounts of these cleaners can quickly break down the lubricating properties of engine oil Use an aerosol gasket remover paint stripper or lacquer thinner to remove any old sealant Apply the solvent allow time for it to work and then brush the surface with a brass wire brush After the old sealant is removed clean the surface with isopropyl alcohol lacquer thinner or aerosol electrical contact cleaner Do not scrape the surfaces as any scratc
312. use a loss of vaporization efficiency Visual inspection and necessary cleaning should be performed on a regular basis more frequently under dusty or dirty conditions The vaporizer should be disassembled cleaned and serviced using a rebuild kit every 1500 hours or if a problem is encountered Figure 5A 17 LPG Regulator The regulator controls both the pressure and flow of fuel within the LP system It is comprised of both a primary and secondary chamber which are dependent upon one another Two different styles of regulators are used based upon the system involved The Impco Beam regulator is shown in Figure 5A 18 and the Nikki regulator is shown in Figure 5A 19 Although the basic design and operating principles are similar due to system differences the regulators should not be interchanged Figure 5A 19 Nikki Regulator Following are separate sections covering the theory of operation and general service information for each style of regulator Detailed service repair instructions are included in the rebuild kit for each regulator 5A 9 Section 5A LPG Fuel Systems Impco Beam Regulator See Figure 5A 20 LPG vapor enters at point A then passes into primary area B at point 28 where pressure is reduced from up to 250 psi at the tank to 4 5 psi in area B Fuel pressure against diaphragm 2 overcomes spring 3 and as movement increases spring 5 will close lever 6 The primary diaphragm breather
313. uter of the entire EFI fuel ignition management system All operating and control functions within the ECU During operation sensors continuously gather data are preset No internal servicing or readjustment may which is relayed through the wiring harness to input be performed lfa problem is encountered and you circuits within the ECU Signals to the ECU include determine the ECU to be faulty contact your source ignition on off crankshaft position and speed of supply Do not replace the ECU without factory RPM throttle position oil temperature exhaust authorization oxygen levels and battery voltage The ECU compares the input signals to the programmed maps in its The relationship between the ECU and the throttle memory to determine the appropriate fuel and spark position sensor TPS is very critical to proper system requirements for the immediate operating conditions operation If the TPS or ECU is changed or the The ECU then sends output signals to set the injector mounting position of the TPS is altered the applicable duration and ignition timing TPS Initialization Procedure see pages 5B 8 or 5B 9 must be performed to restore the synchronization 5B 5 Section 5B EFI Fuel System Engine Speed Sensor k Figure 5B 4 Engine Speed Sensor General The engine speed sensor is essential to engine operation constantly monitoring the rotational speed RPM of the crankshaft A ferromagnetic 60 tooth ring gear with tw
314. uts from the ignition modules The GCU regulates the engine speed by variable input voltage from a customer supplied potentiometer or a single pole single throw SPST switch Potentiometer Specifications Wiper Voltage Engine Speed RPM low speed endpoint Figure 5 41 Electronic Governor Assembly variable speed endpoint 1 Digital Linear Actuator i 2 Throttle Linkage DEP OUO 3 Linkage Spring SPST Switch Specifications 4 Choke Linkage 5 Throttle Lever Adapter Switch Position Engine Speed RPM Open low speed endpoint Closed high speed endpoint NOTE The actual speeds depend on the application Refer to the equipment manufacturer s recommendations GCU Safety Features In the event of an engine overspeed condition the GCU will shut down the engine by grounding the ignition modules The GCU will shut down the engine by grounding the ignition when power to the GCU is lost Linkage The throttle linkage spring will fully open the throttle plate if the linkage becomes detached from the DLA This will create an overspeed condition causing the engine to shut down The DLA shaft will have to be manually screwed back into the body and then retracted before reassembling the linkage Governor Control Unit Figure 5 42 Governor Control Unit Locations 5 23 Section 5 Fuel System and Governor Adjustment Procedure The DLA must be in the fully retracted position during assembly The f
315. utward on the armature splines against the retainer to help seat the collar around the retainer Figure 8 63 Removing Brush Holder 3 Clean the component parts as required 4 The new brushes and springs come preassembled in a brush holder with a protective sleeve that will also serve as an installation tool See Figure 8 64 Figure 8 65 Installing Stop Collar and Retainer NOTE Always use a new retainer Do not reuse old retainers which have been removed 3 Install the offset thrust stop washer so the Figure 8 64 Service Brush Kit smaller offset of the washer faces the retainer collar See Figure 8 66 5 Perform Steps 10 13 in the Starter Reassembly sequence Installation must be done after the armature drive lever and frame are installed if the starter has been disassembled 8 40 Figure 8 66 Installing Thrust Washer 4 Apply a small amount of oil to the bearing in the drive end cap and install the armature with the drive pinion 5 Lubricate the fork end and center pivot of the drive lever with drive lubricant see Section 2 Position the fork end into the space between the captured washer and the rear of the pinion 6 Slide the armature into the drive end cap and at the same time seat the drive lever into the housing NOTE Correctly installed the center pivot section of the drive lever will be flush or below the machined surface of the housing which receives the backup washer S
316. ved from the engine for clarity See Figure 8 14 Section 8 Electrical System and Components ASAM Module Test Connections DSAM Module Test Connections Figure 8 14 Connected Tester Leads The test procedure for twin cylinder SAMs will vary slightly depending on whether the module is analog ASAM or digital DSAM 1 Check the SAM part number stamped on the end of the housing a If itis an ASAM 24 584 09 or 24 584 10 separate the short yellow and brown leads from the long ones Each set will be tested separately Connect the tester to the SAM as follows e Yellow tester lead to long yellow module lead e Brown tester lead to long brown module lead e Red tester lead to the red module lead e Black tester lead to the black or green module lead The remaining tester leads pink and brown with black band are not used for testing ASAMS b Ifitis a DSAM all except 24 584 09 or 24 584 10 connect the tester as follows e Yellow tester lead to the long yellow module lead e Brown tester lead to the long brown module lead e Red tester lead to the red module lead e Black tester lead to the green or black module ground lead with the eyelet terminal e Pink tester lead to the short yellow or pink module lead 8 13 Section 8 Electrical System and Components e Brown tester lead with black band or terminal to the short brown module lead NOTE Some modules contain two black ground leads wit
317. w these instructions carefully to ensure personal safety and proper starter disassembly Make sure adequate face protection is worn by all persons in the area 1 Release the spring tension and remove the handle and the starter rope Refer to Rope Replacement steps 2 through 5 on pages 7 1 and 7 2 2 Remove the center screw washer and pawl retainer See Figure 7 4 3 Remove the brake spring and the brake washer See Figure 7 5 4 Carefully note the positions of the pawls and pawl springs before removing them Remove the pawls and pawl springs from the starter pulley enter Screw d Washers Ww k 08 7 n L a p LL 9 O E AN Da Sa Figure 7 4 Center Screw Washer and Pawl Retainer Section 7 Retractable Starter Figure 7 5 Brake Spring and Washer Pawls and Pawl Springs 5 Rotate the pulley clockwise 2 full turns This will ensure the spring is disengaged from the starter housing 6 Hold the pulley in the starter housing Invert the pulley housing so the pulley is away from your face and away from others in the area 7 Rotate the pulley slightly from side to side and carefully separate the pulley from the housing See Figure 7 6 If the pulley and the housing do not separate easily the spring could be engaged in the starter housing or there is still tension on the spring Return the pulley to the housing and repeat step 5 before separating the
318. wheel Follow the procedures in Section 9 Disassembly and Section 11 Reassembly if stator replacement is necessary Rectifier Regulator The rectifier regulator is mounted on the blower housing See Figure 8 28 To replace it disconnect the plug s remove the two mounting screws and ground wire or metal grounding strap 8 22 NOTE When installing the rectifier regulator take note of the terminal markings and install the plug s accordingly Rectifier Regulator round Strap or lead Figure 8 28 Rectifier Regulator Testing of the rectifier regulator may be performed as follows using the appropriate Rectifier Regulator Tester see Section 2 To Test NOTE Disconnect all electrical connections attached to the rectifier regulator Testing may be performed with the rectifier regulator mounted or loose The figures show the part removed from the engine for clarity Repeat the applicable test procedure two or three times to determine the condition of the part 15 Amp Rectifier Regulators 1 Connect the tester ground lead with spring clamp to the body of the rectifier regulator being tested Connect the tester red lead to the B terminal of the rectifier regulator and the two black tester leads to the two AC terminals See Figure 8 29 Section 8 Electrical System and Components Figure 8 29 3 Plug the tester into the proper AC outlet power for tester being used Turn on the pow
319. wing procedures are provided for troubleshooting ignition problems on SMART SPARK equipped engines They will allow you to isolate and pinpoint the failed component s Special Tools Required e Hand Tachometer e Tester see Section 2 e Automotive timing light e Multi meter digital Specifications Required e Spark plug gap 0 76 mm 0 030 in e Ignition module air gap 0 28 0 33 mm 0 011 0 013 in 0 30 mm 0 012 in nominal NOTE Ignition tester see Section 2 must be used to test ignition on these engines Use of any other tester can result in inaccurate findings Battery on unit must be fully charged and properly connected before making any of these tests a battery that is hooked up or charged backward will crank the engine but it won t have spark Be sure drive is in neutral and all external loads are disconnected drive is in neutral and all external loads are disconnected Test 1 Isolate and verify the trouble is within the engine ignition system 1 Locate the plug connectors where the wiring harnesses from the engine and equipment are joined Separate the connectors and remove the white kill lead from the engine connector Rejoin the connectors and position or insulate the kill lead terminal so it cannot touch ground Try to start the engine to verify whether the reported problem is still present a Ifthe problem is gone the electrical system on the unit is suspect Check the key switch wires c
320. with solenoid Insert the three mounting screws the corresponding slot in the grommet of the through the holes in the drive end cap Use these positive brush lead to hold the solenoid gasket in position then mount the solenoid Torque the screws to 12 Install the two thru bolts and the two brush 4 0 6 0 N m 35 53 in Ib holder mounting screws Torque the thru bolts to 5 6 9 0 N m 49 79 in Ib Torque the brush 14 Connect the positive brush lead bracket holder mounting screws to 2 5 3 3 N m 22 29 in to the solenoid and secure with the hex nut Ib See Figures 8 75 and 8 76 Torque the nut to 8 11 N m 71 97 in Ib Do not overtighten See Figure 8 77 Figure 8 75 Torquing Thru Bolts Figure 8 77 Positive Brush Lead Connection 8 43 Section 8 Electrical System and Components Solenoid Test Procedure Solenoid Shift Style Starters Disconnect all leads from the solenoid including the positive brush lead attached to the lower stud terminal Remove the mounting hardware and separate the solenoid from the starter for testing Test 1 Solenoid Pull In Coil Plunger Actuation Test Use a 12 volt power supply and two test leads Connect one lead to the flat spade S start terminal on the solenoid Momentarily connect the other lead to the lower large post terminal See Figure 8 78 When the connection is made the solenoid should energize audible click and the plunger retract Repeat the test several tim
321. y valve not opening e Secondary or vacuum lock off diaphragm Idle Speed within regulator leaking Adjusting Screw f Low pressure rubber hose kinked g Frozen regulator 5 Improper ignition timing 6 Loose incorrect throttle lever clamp bracket positioning 7 Loose or incorrectly positioned high speed Rear Plug throttle plate stop with Sealing Washer Afer Engine runs lean 1 Electrical problem causing intermittent lock off operation or lock off is faulty 2 Filter in lock off dirty or restricted 3 Restriction in fuel system 4 Idle holes plugged dirt in fuel delivery channels 5 Carburetor fuel circuit restriction di 6 Loose leaking fuel enrichment hose Impco Plastic Bushing Adjusting Screw carburetor system Figure 5A 3 Nikki Carburetor High fuel consumption Impco carburetors also incorporate the use of an 1 Fuel leak Check lines connections and system external Load Block assembly which controls the components for leaks with soapy water Fix any final fuel flow to the carburetor for all throttle leaks immediately positions except idle See Figure 5A 2 Calibrated and 2 Incorrectly set regulator or leakage from valves flow matched to the carburetor it functions similarly in regulator Readjust service or replace to preset fuel mixture settings in other carburetors regulator as required The load block assembly is not available separately 3 Dirty air cleaner or precleaner
322. ywheel seated and parallel with the shaft taper 2 Torque the screws to 9 9 N m 88 in Ib 2 Install the flywheel onto the crankshaft being careful not to shift the woodruff key See Figure Install Plastic Grass Screen 11 28 1 Ifthe engine has a plastic grass screen snap the screen onto the fan See Figure 11 31 Due to the possibility of damaging the posts during removal install the retainers on different posts from which 3 Install the hex flange screw and washer 4 Use a flywheel strap wrench or holding tool to they were removed Start the retainers by hand hold the flywheel Torque the hex flange screw then push them down with a 13 mm 1 2 socket securing the flywheel to the crankshaft to until they lock If the engine has a metal screen it 66 4 N m 49 ft Ib See Figure 11 29 will be installed later Figure 11 29 Installing and Torquing Flywheel Figure 11 31 Installing Plastic Grass Screen Fastener Section 11 Reassembly Install Supports for the Metal Grass Screen 1 Ifa metal grass screen is used with threaded individual supports install a spacer washer on the external threads Apply blue Loctite No 242 removable onto the threads Install the four supports as shown in Figure 11 32 Figure 11 34 Applying Camshaft Lubricant to Bottom of Lifters 3 Note the mark or tag identifying the hydraulic lifters as either intake or exhaust and cylinder 1 or cylinder 2 Install the hydraulic lif

Ch26 / Ch620

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