Home

LH775 Service Manual

1. Cylinder Head Cylinder Head Fastener torque in 2 increments first to 16 9 N m 150 in Ib finally to 33 9 N m 300 in Ib Rocker Pivot Fastener 11 3 N m 100 in Ib Values are in Metric units Values in parentheses are English equivalents Exceeding maximum angle of operation may cause engine damage from insufficient lubrication Lubricate threads with engine oil prior to assembly 8 Any and all horsepower hp references by Kohler are Certified Power Ratings and per SAE J1940 8 J1995 hp standards Details on Certified Power Ratings can be found at KohlerEngines com 6 KohlerEngines com 66 690 07 Rev B Specifications TORQUE SPECIFICATIONS LH775 Electric Starter 2 5 3 3 N m 22 29 in Ib 4 0 6 0 N m 35 53 in Ib Starter Solenoid Positive Brush Lead Retaining Nut 8 0 11 0 N m 71 97 in Ib Fan Flywheel Lower Flywheel Cover Mounting Screw into hex or weld nuts 9 9 N m 88 in Ib into Timmerman clips nuts 2 2 2 8 N m 20 25 in Ib 24 3 N m 215 in Ib Governor 6 8 N m 60 in Ib Ignition Spark Plug 2 N m 20 ft Ib Ignition Module Fastener m 55 in Ib into new hole m 35 in Ib into used hole Rectifier Regulator Fastener 4 0 N m 35 in Ib Muffler Muffler Retaining Nuts 24 4 N m 216 in Ib Speed Control Speed Control Bracket Assembly Fastener 10 7 N m 95 in Ib into new holes 7 3 N m 65 in Ib into used holes otator Stator Mounting Sc
2. TPS Sensor Related e Throttle plate position incorrectly set or registered during Initialization e TPS problem or malfunction Engine Wiring Harness Related e Difference in voltage between sensed voltage pin 2 and actual injector voltage circuit 45 45A Systems Related e Ignition spark plug plug wire ignition coil e Fuel fuel type quality injector fuel pump fuel pressure Combustion air air cleaner dirty restricted intake leak throttle bores Base engine problem rings valves Exhaust system leak Fuel in crankcase oil Blocked or restricted fuel return circuit to tank ECU Harness Related e ECU to harness connection problem Code 34 Component Oxygen Sensor Fuel System Components Condition Conclusion KohlerEngines com Long term fuel adaptation control is at upper or lower limit System operates closed loop No appreciable performance loss as long as temporary adaptation can provide sufficient compensation Oxygen Sensor Related e Sensor connector or wiring problem Sensor contaminated or damaged Exhaust leak Poor ground path Pin circuit wiring or connectors Pin 20 TPS Sensor Related e Throttle plate position incorrect during Initialization procedure e TPS problem or malfunction Engine Wiring Harness Related e Difference in voltage between sensed voltage pin 2 and actual injector voltage circuit 45 45A e Problem in wiring harness e ECU to harness
3. 1 Remove mounting screws and pull stator with plug in connector attached from engine Remove Intake Manifold Thermostat Housing By pass Hose and Wiring Harness 1 Disconnect by pass hose from fitting on water pump 2 Remove six mounting screws and carefully separate intake manifold from cylinder heads with by pass hose and wiring harness attached 3 Remove intake manifold gaskets 4 Further disassembly of intake manifold components may be performed as necessary If thermostat is to be removed loosen and remove screws securing thermostat housing to intake manifold Separate housing and remove thermostat discard old gasket O rings and retaining clips should be replaced any time fuel injector is separated from its normal mounting position Water Pump Components pel ar ra Li Let 3 d 1 t F a d S Tu D Ca E i p PE x A om B Water Pump C Water Pump Belt D Camshaft Pulley E Transfer Tube Remove Camshaft Pulley and Water Pump Belt 1 Remove screw and flat washer securing cogged drive pulley to camshaft 2 Carefully lift pulley off camshaft and remove belt from water pump pulley 3 Remove camshaft key from keyway Remove Water Pump and Transfer Tube 1 Loosen and unscrew hex cap section securing transfer tube to 90 fitting in crankcase Support fitting with a wrench when loosening hex cap section 66 KohlerEngines com 2 Remove screws securing w
4. 18 KohlerEngines com 66 690 07 Rev B AIR CLEANER These systems are CARB EPA certified and components should not be altered or modified in any way Air Cleaner Housing B Inner Element RetainingClip D Element E End Cap F Dust Ejector Valve NOTE Operating engine with loose or damaged air cleaner components could cause premature wear and failure Replace all bent or damaged components NOTE Paper element cannot be blown out with compressed air 1 Unhook retaining clips and remove end cap s 2 Check and clean inlet screen if equipped 3 Pullair cleaner element out of housing and replace Check condition of inner element replace when dirty 4 Check all parts for wear cracks or damage and that ejector area is clean 5 Install new element s 6 Reinstall end cap s with dust ejector valve screen down secure with retaining clips 66 690 07 Rev B Air Cleaner Intake BREATHER TUBE Ensure both ends of breather tube are properly connected AIR COOLING zh Hot Parts can cause severe burns uiiA Do not touch engine while operating or just after stopping Never operate engine with heat shields or guards removed NOTE Operating engine with a restricted air intake screen or radiator damaged broken fan assembly or missing fan shroud will cause engine damage due to over heating Proper cooling is essential To prevent over heating clean screens cooling fins and other
5. 41 EFI System Code 52 Component Injector 2 circuit open shorted to ground or shorted to battery Fault Injector 2 is not functioning because circuit is open shorted to ground or shorted to battery Condition Engine will run very poorly with only one cylinder functioning Conclusion Injector Related e Injector coil shorted or opened Engine Wiring Harness Related e Broken or shorted wire in harness ECU pin 15 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 e Opened main fuse F1 Fuel Pump Relay Related 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 ECU Related e Circuit controlling injector 2 damaged e Circuit controlling fuel pump relay damaged Code 55 Component MIL Diagnostic lamp circuit open shorted to ground or shorted to battery Fault MIL is not functioning because circuit is open shorted to ground or shorted to battery Condition Engine will run normally if no other errors are present Conclusion MIL diagnostic lamp Related e MIL element opened or element shorted to ground e Lamp missing Engine Wiring Harness Related e Broken or shorted wire in harness ECU pin 29 to lamp
6. Cil Pressure Test Kit Kohler 25 761 06 S For testing verifying oil pressure on pressure lubricated engines Radiator Tester Kohler 25 455 10 S For pressure testing radiator and cap on Aegis liquid cooled engines Rectifier Regulator Tester 120 volt current Kohler 25 761 20 S Rectifier Regulator Tester 240 volt current Kohler 25 761 41 S For testing rectifier regulators Components of 25 761 20 S and 25 761 41 S Design Technology Inc CS PRO Regulator Test Harness DTI 031 Special Regulator Test Harness with Diode DTI 033 Spark Advance Module SAM Tester Kohler 25 761 40 S For testing SAM ASAM and DSAM on engines with SMART SPARK Starter Servicing Kit All Starters SE Tools KLR 82411 For removing and reinstalling drive retaining rings and brushes Individual component available Starter Brush Holding Tool Solenoid Shift SE Tools KLR 82416 Triad OHC Timing Tool Set Kohler 28 761 01 S For holding cam gears and crankshaft in timed position while installing timing belt Valve Guide Reamer K and M Series Design Technology Inc For properly sizing valve guides after installation DTI K828 Valve Guide Reamer O S Command Series Kohler 25 455 12 S For reaming worn valve guides to accept replacement oversize valves Can be used in low speed drill press or with handle below for hand reaming Reamer Handle Design Technology Inc For hand reaming using Kohler 25 455 12 S reamer DTI K830 Valve Guide Service Kit Courage Aegis
7. KohlerEngines com ECU internal memory problem e Diagnosable only through elimination of all other system component faults 66 690 07 Rev B Code 24 Will not blink out Engine Speed Sensor Fault No tooth signal from speed sensor MIL light will not go out when cranking Condition None engine will not start or run as ECU is unable to estimate speed Conclusion Engine Speed Sensor Related e Sensor connector or wiring e Sensor loose or air gap incorrect Speed Sensor Wheel Related e Damaged teeth e Gap section not registering Engine Wiring Harness Related e Pin circuit wiring or connectors Pin s 9 and or 10 ECU Harness Related e ECU to harness connection problem Code 31 Fault System too lean Oxygen sensor not sending expected voltage to ECU Condition 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 itis shorted to battery voltage After fault is detected performance can vary depending on cause If performance is pretty good problem is probably with oxygen sensor wiring or connectors If engine is still running rich laboring short on power or lean popping or misfiring fuel mixture is suspect probably incorrect TPS initialization or low fuel pressure TPS Initialization Incorrect e Lean condition check oxygen sensor signal with VOA and see Oxygen Sensor
8. Pressure Regulating n Chamber Diaphragm ValveSeat ValveSeat Outlet Port Fuel Chamber to fuel rail G Return Port to tank H Inlet Port Depending on application regulator may be located in fuel tank along with fuel pump or outside tank just down line from pump Regulator is a sealed non serviceable assembly If it is faulty it must be separated from base holder assembly and replaced as follows 1 Shut engine off make sure engine is cool and disconnect negative battery cable 2 Depressurize fuel system through test valve in fuel rail 3 Access regulator assembly as required and clean any dirt or foreign material away from area 4 External Regulator a Remove screws securing mounting bracket to regulator housing Remove O ring and pull regulator out of housing b Remove snap ring and remove regulator from base holder Internal In Tank Regulator Remove screws securing retaining ring and regulator in base holder assembly Grasp and pull regulator out of base holder 66 690 07 Rev B 5 Always use new O rings and hose clamps when installing a regulator Anew replacement regulator will have new O rings already installed Lubricate O rings external regulator with light grease or oil 6 Install new regulator by carefully pushing and rotating it slightly into base or housing a External Regulators with Square Base Housing Only Install a new O ring between r
9. 0 2358 0 2362 in Max Wear Limit 5 977 mm 0 2353 In Governor Gear Shaft to Governor Gear Running 0 090 0 160 mm 0 0035 0 0063 in Clearance Ignition Spark Plug Gap 0 76 mm 0 030 in Ignition Module Air Gap 0 203 0 305 mm 0 008 0 012 in Piston Piston Rings and Piston Pin Piston Style A Piston to Piston Pin 0 006 0 018 mm 0 0002 0 0007 in Piston Pin Bore I D New 17 006 17 013 mm 0 6695 0 6698 in Max Wear Limit 17 025 mm 0 6703 in Piston Pin O D New 16 995 17 000 mm 0 6691 0 6693 in Max Wear Limit 16 994 mm 0 6691 in Top Compression Ring to Groove Side Clearance 0 014 0 041 mm 0 0005 0 0016 in Middle Compression Ring to Groove Side Clearance 0 012 0 039 mm 0 0004 0 0015 in Oil Control Ring to Groove Side Clearance 0 026 0 176 mm 0 0010 0 0070 in Top and Middle Compression Ring End Gap New Bore 0 250 0 56 mm 0 0098 0 022 in Max Wear Limit 82 841 mm 3 3136 in Piston Thrust Face to Cylinder Bore Running 0 015 0 058 mm 0 005 0 0022 in Clearance Used Bore Max 0 94 mm 0 037 in Piston Thrust Face O D New 82 973 82 991 mm 3 2666 3 2673 in Values are in Metric units Values in parentheses are English equivalents Measure 6 mm 0 2362 in above bottom of piston skirt at right angles to piston pin 66 690 07 Rev B KohlerEngines com 9 Specifications CLEARANCE SPECIFICATIONS LH775 Piston Piston Rings and Piston Pin continued
10. Bleeding Lifters To prevent a possible bent push rod or broken rocker arm it is important to bleed any excess oil out of lifters before they are installed 1 Cuta 50 75 mm 2 3 in piece from end of an old push rod and chuck it in a drill press 2 Lay a rag or shop towel on table of drill press and place lifter open end up on towel 3 Lower chucked push rod until it contacts plunger in lifter Slowly pump plunger two or three times to force oil out of feed hole in side of lifter KohlerEngines com 69 Disassembly Inspection and Service Crankcase Components eh Locking Tab Thrust Washer Gerotor Gears Camshaft D Style A Oil Filter Crankshaft P Connecting Rod Piston Style A T Closure Plate Style B Oil Pump Cover O ring X Outer Gerotor Gear Style B Style B Oil Seal D Closure Plate Style T Governor Gear Shaft nenn enen Oil Pump Assembly Style A Nipple M Governor Cross Shaft Piston Pin Retainer O PistonPin 2 Piston Style B R Piston Ring Set Ball Style B V Spring Style B Oil P A bl Sty eB y D Oil Pick Up Style B Remove Closure Plate Hold handle horizontal and pull it toward you to break RTV seal If necessary pry at bottom splitting 1 Remove screws securing closure plate to crankcase tabs also Do not pry on sealing surfaces as this If a thick washer is installed under screw head in 10 could cause leaks Carefully pull closure plate from locati
11. Command OHC SE Tools KLR 82415 For servicing worn valve guides AIDS Description Source Part No RTV Silicone Sealant Loctite 5900 Heavy Body in 4 oz aerosol dispenser Kohler 25 597 07 S Only oxime based oil resistant RTV sealants such as those listed are approved Loctite 59109 for use Loctite Nos 5900 or 5910 are recommended for best sealing Loctite Ultra Black 598 characteristics Loctite Ultra Blue 587 Loctite Ultra Copper 5920 Spline Drive Lubricant Kohler 25 357 12 S 66 690 07 Rev B KohlerEngines com 13 Tools and Aids FLYWHEEL HOLDING TOOL A flywheel holding tool can be made out of an old junk flywheel ring gear and used in place of a strap wrench 1 Using an abrasive cut off wheel cut out a six tooth segment of ring gear as shown 2 Grind off any burrs or sharp edges 3 Invert segment and place it between ignition bosses on crankcase so tool teeth engage flywheel ring gear teeth Bosses will lock tool and flywheel in position for loosening tightening or removing with a puller ROCKER ARM CRANKSHAFT TOOL A spanner wrench to lift rocker arms or turn 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 rod cap 2 Remove studs of a Posi Lock rod or grind off aligning steps of a Command rod so joint surface is flat 3 Finda 1 in long capscrew with correct thread size to match
12. If an injector is not operating it can indicate either a bad injector or a wiring electrical connection problem Check as follows 1 Disconnect electrical connector from both injectors Plug a 12 volt noid light part of EFI Service Kit into one connector 1 Engine must be cool Depressurize fuel system through test valve in fuel rail Disconnect spark plug leads from spark plugs Remove air cleaner outer cover inner wing nut element cover and air cleaner element precleaner Service air cleaner components as required Remove screws securing air cleaner base to throttle body manifold Remove air cleaner base to permit access to injectors Check condition of air cleaner base gasket replace if necessary Remove flywheel screen if it overlaps blower housing If engine has a radiator type oil cooler mounted to blower housing remove oil cooler mounting screws 28 KohlerEngines com 66 690 07 Rev B 7 Remove blower housing mounting screws Note location of plated silver screw attaching rectifier regulator ground lead Remove blower housing 8 Thoroughly clean area around and including throttle body manifold and injectors 9 Disconnect throttle linkage and damper spring from throttle lever Disconnect TPS lead from harness 10 Remove manifold mounting bolts and separate throttle body manifold from engine leaving TPS fuel rail air baffle injectors and line connections intact Discard old gaskets 11 Positio
13. Piston Style B Piston to Piston 0 006 0 017 mm 0 0002 0 0007 in Piston Pin Bore I D New O 17 006 17 012 mm 0 6695 0 6698 in Max Wear Limit 17 025 mm 0 6703 in Piston Pin O D New O 16 995 17 000 mm 0 6691 0 6693 in Max Wear Limit 16 994 mm 0 6691 in Top Compression Ring to Groove Side Clearance 0 030 0 070 mm 0 001 0 0026 in Middle Compression Ring to Groove Side Clearance 0 030 0 070 mm 0 001 0 0026 in in Oil Control Ring to Groove Side Clearance 0 060 0 190 mm 0 0022 0 0073 in Top Compression Ring End Gap New Bore 0 189 0 277 mm 0 0074 0 0109 in Used Bore Max 0 531 mm 0 0209 in Middle Compression Ring End Gap New Bore 1 519 1 797 mm 0 0598 0 0708 in Used Bore Max 2 051 mm 0 0808 in Piston Thrust Face O D New 82 978 mm 3 2668 in 2668 in 82 833 mm 3 2611 in ij Piston Thrust Face to Cylinder Bore Running 0 019 0 062 mm 0 0007 0 0024 in Clearance Valves and Valve Lifters Hydraulic Valve Lift er to Crankcase Running 0 0124 0 0501 mm 0 0005 0 0020 in Clearance 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 0 050 0 088 mm 0 0020 0 0035 in Clearance Intake Valve Guide I D New 7 038 7 058 mm 0 2771 0 2779 in Max Wear Limit 7 134 mm 0 2809 in Intake Valve Stem Diameter New 6 982 7 000 mm 0 2749 0 2756 in Exhaust Valve Stem Diameter New 6 970 6 988
14. Spark plug lead boot loose on plug Spark plug lead loose Engine Will Not Idle Engine overheated Faulty spark plug s Idle fuel adjusting needle s improperly set Idle speed adjusting screw improperly set Inadequate fuel supply Low compression Quality of fuel dirt water stale mixture Restricted fuel tank cap vent Engine Overheats Cooling fan broken Excessive engine load Fan belt failed off Faulty carburetor High crankcase oil level Lean fuel mixture Low cooling system fluid level Low crankcase oil level Radiator and or cooling system components clogged restricted or leaking Water pump belt failed broken Water pump malfunction Engine Knocks Excessive engine load Hydraulic lifter malfunction Incorrect oil viscosity type Internal wear or damage Low crankcase oil level Quality of fuel dirt water stale mixture KohlerEngines com 15 Troubleshooting Engine Loses Power e Dirty air cleaner element e Engine overheated e Excessive engine load e Restricted exhaust e Faulty spark plug s e High crankcase oil level e Incorrect governor setting e Low battery e Low compression e Low crankcase oil level e Quality of fuel dirt water stale mixture Engine Uses Excessive Amount of Oil e Loose or improperly torqued fasteners e Blown head gasket overheated e Breather reed broken e Clogged broken or inoperative crankcase breather e Crank
15. l their original location p Remove Cylinder Heads and Valve Lifters NOTE It is not necessary to remove cylinder studs from crankcase unless replacement is intended If studs are removed for any reason discard old stud s do not reuse reinstall Use new studs and refer to assembly sequence for proper installation 1 Rotate crankshaft of engine until valves of one cylinder are closed Loosen rocker arm screws until rocker arms can be pivoted to free push rods 66 690 07 Rev B KohlerEngines com 67 Disassembly Inspection and Service Inspection and Service Valve Details EXHAUST VALVE hes A Dimension Intake Seat Angle 89 Guide Depth D Guide 1 D Valve Head Diameter F Valve Face Angle 45 G Valve Margin Min Valve Stem Diameter 36 987 37 013 mm 1 4562 1 4572 in 4 mm 0 1575 in 7 038 7 058 mm 0 2771 0 2779 in 33 37 33 63 mm 1 3138 1 3240 in Disassemble Cylinder Heads NOTE These engines use a valve stem seal on intake and exhaust valves Serial No 3422000010 and lower used a seal on intake side only Always use new seals when valves are removed from cylinder head Replace seals if they are deteriorated or damaged in any way Never reuse an old seal 1 Remove screws rocker arms and pivots from cylinder head s 2 Compress valve springs using a valve spring compressor and remove valve spring keepers Remove compressor 68 KohlerEngines com 1 5 mm 0 0591 in 6
16. score marks running and side clearances Replace rod and cap if scored or excessively worn Service replacement connecting rods are available in STD crankpin size and 0 25 mm 0 010 in undersize An 0 25 mm 0 010 in undersized rod can be identified by a drilled hole located in lower end of rod shank Always refer to appropriate parts information to ensure correct replacements are used KohlerEngines com 3 Disassembly Inspection and Service Remove Crankshaft Inspect crankshaft keyways If they are worn or chipped replacement of crankshaft will be necessary Inspect 1 Carefully pull crankshaft from crankcase Note thrust _crankpin for score marks or metallic pickup Slight score washer and shims if used marks can be cleaned with crocus cloth soaked in oil If Inspection and Service wear limits as stated in Clearance Specifications are exceeded it will be necessary to replace crankshaft or Crankshaft Components and Details regrind 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 crankpin for size taper and out of round Connecting rod journal can be ground 1 size under When grinding a crankshaft grinding stone deposits can get caught in oil passages which could cause severe engine damage Removing crankpin plug when crankshaft is ground provides easy access for removing any grinding depo
17. 3 SUE or SUA WESC B WEE lu Pn yas WO oui Aly v ALON CNIONIOHO _ 335 T OMNNOHO AJILI Ya U KE HiM d Mi 2 UON OM OM 335 Ygl ziCy DK l Dn ed W Av L n LIT AP 3MI1 3 21 5ONDvIQ E m Dr JE ial ae EH j a 310N IKAMA 335 JU SONSICI HOLOJNNOO JOS UE uonisog BTL H 2 ssi Si Sui Sa PS cicli flee z d AA T fa Mai JOG URS an pCa ISIO d dn a e a k bg alls lle Lab ag Rr KEE Ga CEET E le Sy mp Fast US RE Fang c4 ums qToakd e p gd pccnod ae paga DOE gj usan m bou na ibrar da guru r open aure p va DATA xu 24 M d AL Nete 94 ULL OHA VM Tu n pou par T WOLO3TNI 35 pns ici ding eut 03 AR F 4ERT 3 iue Ier L di ix 03345 3NInN3 10 U Z U 8 2 M Wi 2 x 8 E n gt B S Z D X C 8 4 rd ba d J A ci C s W Ona kaj c ON sz i AA 9 KLIS lt ALIS S 66 690 07 Rev B EFI System FUEL SYSTEM A WARNING Explosive Fuel can cause fires and severe burns Wrap a shop towel completely around fuel pump module connector Press release button s and slowly pull connector away from fuel pump module allowing shop towel to absorb any residual fuel in high pressure fuel line Any spilled fuel must be completely wiped up immediately Fuel system ALWAYS remains under HIGH PRESSURE Function of fuel system is to provide sufficient
18. AOF 23 C or below If battery charge is insufficient to turn over engine recharge battery Battery Maintenance Regular maintenance is necessary to prolong battery life Battery Test To test battery follow manufacturer s instructions BATTERY CHARGING SYSTEM NOTE Observe following guidelines to avoid damage to electrical system and components e Make sure battery polarity is correct A negative ground system is used e Disconnect rectifier regulator plug and or wiring harness plug before doing any electric welding on equipment powered by engine Also disconnect all other electrical accessories in common ground with engine e Prevent stator AC leads from touching or shorting while engine is running This could damage stator These engines are equipped with a 25 amp regulated charging system 66 690 07 Rev B KohlerEngines com 49 Electrical System 25 Amp Regulated Charging System Flywheel Stator m Connector Block Lm Assembly Stator Stator is mounted on crankcase behind flywheel Follow procedures in Disassembly Inspection and Service and Reassembly if stator replacement is necessary Rectifier Regulator NOTE When installing rectifier regulator take note of terminal markings and install plug s accordingly NOTE Disconnect all electrical connections attached to rectifier regulator Testing may be performed with rectifier regulator mounted or loose Repeat applicable test procedure two or three tim
19. Assembly cleaner mounting bracket Install and finger tighten 1 Reassemble components of radiator assembly four mounting screws including upper and lower radiator hoses Rubber 5 Connect upper and lower radiator hoses to inlets of lubricant may be applied to inner surfaces of hoses radiator and water pump Secure with hose clamps to make installation easier Secure with hose Make sure tangs of upper clamp face away from fan clamps 6 Check for adequate clearance between fan and 2 Tighten radiator drain plug shroud Adjust lower radiator supports as required then torque four mounting screws to 9 9 N m 88 in Ib External Engine Components e A Dipstick B Electric Starter Adapter Plate D Oil Drain Plug E Flywheel Cover F Radiator Drain Plug 66 690 07 Rev B KohlerEngines com 89 Reassembly 7 Hold radiator assembly in position then torque Screws securing two upper radiator supports to 9 9 N m 88 in Ib 8 If securing upper brackets to top radiator mounts were loosened torque to 9 9 N m 88 in Ib Install Ignition Modules 1 Install ignition module to mounting bracket Position spacer between ignition module and mounting bracket and torque screws to 6 2 N m 55 in Ib into new hole or 4 0 N m 35 in Ib into used hole 2 Repeat step 1 for other ignition module 3 Connect leads to ignition modules Install Starter Adapter 1 Install starter adapter to crankcase so
20. Clearance New Main Bearing Journals O D New O D Max Wear Limit Max Taper Max Out of Round Crankshaft to Sleeve Bearing crankcase Running Clearance New Connecting Rod Journal O D New O D Max Wear Limit Max Taper Max Out of Round Crankshaft T I R PTO End Crank in Engine Entire Crank in V Blocks Cylinder Bore Cylinder Bore TD New Max Wear Limit 40 974 40 987 mm 1 6131 1 6136 in 41 000 mm 1 6141 in 40 974 41 000 mm 1 6131 1 6141 in 41 038 mm 1 6156 in 0 039 0 087 mm 0 0015 0 0034 in 40 913 40 935 mm 1 6107 1 6116 in 40 84 mm 1 608 in 0 022 mm 0 0009 in 0 025 mm 0 0010 in 0 039 0 074 mm 0 0015 0 0029 in 35 955 35 973 mm 1 4156 1 4163 in 35 94 mm 1 415 in 0 018 mm 0 0007 in 0 025 mm 0 0010 in 0 15 mm 0 0059 in 0 10 mm 0 0039 in 83 006 83 031 mm 3 2679 3 2689 in 83 069 mm 3 2704 in Max Out of Round 0 12 mm 0 0047 in Max Taper 0 05 mm 0 0020 in Cylinder Head Max Out of Flatness 0 076 mm 0 003 in Values are in Metric units Values in parentheses are English equivalents 8 KohlerEngines com 66 690 07 Rev B Specifications CLEARANCE SPECIFICATIONS LH775 Governor Governor Cross Shaft to Crankcase Running 0 025 0 126 mm 0 0009 0 0049 in Clearance Governor Cross Shaft O D New 7 949 8 000 mm 0 3129 0 3149 in Max Wear Limit 7 936 mm 0 3124 in Governor Gear Shaft O D New 5 990 6 000 mm
21. Insert barbed gauge fitting into hole in stopper at 0 line Make sure pinch clamp is closed 3 Run engine and observe gauge reading 2 Start engine and run no load high speed 3 0 zm ereen Analog tester needle movement to left of O is a amp Spence z o o n u vacuum and movement to right indicates a pressure Level in engine side should be a minimum of Digital tester depress test button on top of tester 10 2 cm 4 in above level in open side a H l m Crankcase vacuum should be a minimum of 10 2 cm ee nens ee alla e A 4 in of water If reading is below specification or if Re ed GE e dea D pressure is present check table below for possible P P causes and conclusions below 4 Close pinch clamp before stopping engine Condition Conclusion Crankcase breather clogged or inoperative NOTE If breather is integral part of valve cover and cannot be serviced separately replace valve cover and recheck pressure Disassemble breather clean parts thoroughly check sealing surfaces for flatness reassemble and recheck pressure Seals and or gaskets leaking Loose or improperly torque Replace all worn or damaged seals and gaskets Make fasteners sure all fasteners are tightened securely Use appropriate torque valves and sequences when necessary Piston blow by or leaky valves confirm by inspecting Recondition piston rings cylinder bore valves and components valves guides Restricted exhaust Check exhaust
22. O O O o O O O o o O O o000000000000000 66 690 07 Rev B EFI System t pue Eupd Sal O Saja GI Bu salga WO AAS GL BL Je epis LIBYE BU eui Wty paa se oe np ueda api apr uscuj zd aui jo Von AAC 204 i unns UMD Ej jesus uomsod agyeuu au r AL po agna Bug poa F uim 3pAG 3p Agr oi at sBegos Durgrado puo jeje d uj pepe FILA qua emoce po sape gau E Seana ELL pesi agues CTT gu pz e Ajo duse Wa1sgpugu WOOO EL E eq ug 1 dwe BODU VOTEN UN LUK Ue p usA pgd pap E ag jas np ue e sued sava Jnsuies peads OARVEL og Sei UE hagi3eds esisuagn ssajur Fuur Buung WO Beds r123 eu BOJ WU A4 eq En aeon weyets ayy upea Buung AOWA EES out EJE o ul Z po Aep ana E ba Ar JO aBzgas wasis um un ur e gue snw AE ayp wado ur pou ann IDA jeupe AL ung pap afigumip sadoxd app c LO SEELEY gll SUUNA PALMON sj Buren rya eur EU Pp gel 53 JI ASAU Lue As Esci saga pasad apnasn ag SMW Jeng po ax nd wess assez E aug tps Enid eds aes YA Paul GUNA SEPPI JO mure 23 use Pee ag pu jeg Cas Bi tuer ep En peo saua puje ued ot aod au oun aj pasn ac Amu F eut Pope g H uou Spy cani yaa peas e gaupas ups uoga eui D L Lr aigue wejsAs pue jg PUB Ge 43 68 tna AE OA Jaara airpad saadaa UA du o pip juana Weeks pa DBP BU iayo 3g jo A Z FF Up pa Er Ltr pug Z GG pi sanan uc afigpo au Buss Buunp pass x53 asand oj uojgsad uru su c Ups aui way aus E EL ee E Fe a e o4 a SL ax out se z Lr pue cg
23. With sensor connected check oil temperature sensor circuit resistance Check between 6 and 4 pin terminals Value should be 2375 2625 Q o Unplug sensor connector and check sensor resistance separately Resistance value should again be 2375 2625 O a If resistance is out of specifications replace temperature sensor b If it is within specifications proceed to Step 6 6 Check temperature sensor circuits input ground from main harness connector to corresponding terminal in sensor plug for continuity damage etc Pin circuits 6 and 4 KohlerEngines com 25 EFI System OKYGEN SENSOR Cutaway of Orygen Sensor E Connection Cable rer Disc Spring Ceramic Support z Contact Element F Sensor Housing Active Ceramic e Sensor NOTE All tests should be conducted with a good quality high impedance digital VOA meter for accurate results Like other sensors already discussed oxygen sensor is a non serviceable component Complete replacement is required if it is faulty Sensor and wiring harness can be checked as follows 1 Oxygen sensor must be hot minimum of 400 C 752 F Run engine for about 5 minutes With engine running disconnect oxygen sensor lead from wiring harness Set VOA meter for DC volts and connect red lead to disconnected sensor lead and black lead to sensor shell Look for a voltage reading from 0 2 v 1 0 v a If voltage is in specified range go to Step 2 b If voltage is no
24. connection problem Systems Related e Ignition spark plug plug wire ignition coil e Fuel fuel type quality injector fuel pressure fuel pump Combustion air air cleaner dirty restricted intake leak throttle bores Base engine problem rings valves Exhaust system leak muffler flange oxygen sensor mounting boss etc Fuel in crankcase oll e Altitude e Blocked or restricted fuel return circuit to tank 66 690 07 Rev B Code 42 Engine Oil Temperature Sensor Not sending proper signal to ECU Condition Engine may be hard to start because ECU can t determine correct fuel mixture Conclusion Temperature Sensor Related e Sensor wiring or connection Engine Wiring Harness Related e Pin circuits 4 6 and or 4A damaged wires connectors or routed near noisy signal coils alternator etc e ECU to harness connection problem System Related e Engine is operating above 176 C 350 F temperature sensor limit Code 43 and 44 Component TPS Auto Learn initialization function failed throttle angle out of learning range Fault While performing TPS Auto Learn function measured throttle angle was not within acceptable limits Condition 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 Conclusion TPS Related e TPS rotated on throttle shaft assembly bey
25. external surfaces of engine Avoid spraying water at wiring harness or any electrical components See Maintenance Schedule KohlerEngines com 19 EFI System A WARNING Gasoline is extremely flammable and its vapors can explode if ignited Store gasoline only in approved Explosive Fuel can cause fires and severe containers in well ventilated unoccupied buildings away burns from sparks or flames Spilled fuel could ignite if it comes Do not fill fuel tank while engine is hot or in contact with hot parts or sparks from ignition Never running use gasoline as a cleaning agent EFI System e Throttle Position Engine Coolant EE Oxygen Sensor Idle Speed Screw K Adjusting Cable L Speed Sensor Bracket M Speed Sensor D Fuel Filter o Fuel Pump e i 20 KohlerEngines com 66 690 07 Rev B Typical electronic fuel injection EFI system and related components include Fuel tank and valve Fuel pump Fuel filter Fuel rail Fuel line s Fuel injectors Fuel pressure regulator Throttle body intake manifold Electronic control unit ECU Ignition coils Engine oil temperature sensor Throttle position sensor TPS Speed sensor Crankshaft position sensor Oxygen sensor Wire harness assembly amp affiliated wiring Malfunction indicator light MIL Intake air temperature sensor FUEL RECOMMENDATIONS Refer to Maintenance FUEL LINE Low permeation fuel line must be installed on all Kohl
26. flywheel WARNING a Hot liquid can cause 09 57 severe burns Do not loosen radiator cap while engine is operating or warm to touch Liquid coolant can get extremely hot from operation Turning radiator cap when engine is hot can allow steam and scalding liquid to blow out and burn you severely Shut off machine Only remove radiator cap when cool enough to touch with bare hands Slowly loosen cap to first stop to relieve pressure before removing completely WARNING Explosive Fuel can cause fires and severe burns Fuel system ALWAYS remains under HIGH PRESSURE Wrap a shop towel completely around fuel pump module connector Press release button s and slowly pull connector away from fuel pump module allowing shop towel to absorb any residual fuel in high pressure fuel line Any spilled fuel must be completely wiped up immediately 66 690 07 Rev B Maintenance MAINTENANCE INSTRUCTIONS A WARNING Accidental Starts can cause severe injury or Before working on engine or equipment disable engine as death follows 1 Disconnect spark plug lead s 2 Disconnect Disconnect and ground spark plug lead s negative battery cable from battery before servicing 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 dealer MAINTENA
27. from inadequate or contaminated lubrication 66 690 07 Rev B Disassembly Inspection and Service If cylinder bore is badly scored excessively worn tapered or out of round resizing is necessary Use an inside micrometer to determine amount of wear then select nearest suitable oversize of either 0 08 mm 0 003 in 0 25 mm 0 010 in or 0 50 mm 0 020 in Resizing to one of these oversizes will allow usage of available oversize piston and ring assemblies Initially resize using a boring bar then use following procedures for honing cylinder Honing Detail 23 33 Crosshatch While most commercially available cylinder hones can be used with either portable drills or drill presses use of a low speed drill press is preferred as it facilitates more accurate alignment of bore in relation to 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 that stones are in contact with cylinder wall Use of a commercial cutting cooling agent is recommended 2 With lower edge of each stone positioned even with lowest edge of bore start drill and honing process Move hone up and down while resizing to prevent formation of cutting ridges Check size frequently 3 When bore is within 0 064 mm 0 0025 in of desired size remove coarse stones and replace w
28. improper grounds in system battery ECU oxygen sensor shielding fuel pump ignition output e Pin circuits 9 and or 10 routed near noisy electrical signals coils spark plug lead plug connector ECU Harness Related e ECU to harness connection problem Ignition System Related e Non resistor spark plug s used Code 23 Unrecognizable signal is being sent from sensor too high too low inconsistent A limp home operating mode occurs with an overall decrease in operating performance and efficiency Fuel delivery is based upon oxygen sensor and five mapped values only Rich running black smoke will occur until closed loop operation is initiated A stumble or misfire on hard acceleration and or erratic operation may be exhibited TPS Sensor Related e Sensor connector or wiring e Sensor output affected or disrupted by dirt grease oil wear or breather tube position must be to side opposite 9 e Sensor loose on throttle body manifold Throttle Body Related e Throttle shaft or bearings worn damaged Engine Wiring Harness Related e Pin circuits 4 8 and or 18 damaged wiring connectors e Pin circuits 4 8 and or 18 routed near noisy electrical signal coils alternator e Intermittent 5 volt source from ECU pin circuit 18 ECU Harness Related e ECU to harness connection problem ECU is unable to recognize or process signals from its memory Engine will not run Conclusion
29. interrupted input signal corresponding to specific crankshaft position 84 BTDC for cylinder 1 This signal serves as a reference for control of ignition timing by ECU Synchronization of inductive speed pickup and crankshaft position takes place during first two revolutions each time engine is started Sensor must be properly connected at all times If sensor becomes disconnected for any reason engine will quit running Throttle position sensor TPS is used to indicate throttle plate angle to ECU Since throttle by way of governor reacts to engine load angle of throttle plate is directly related to load on engine Mounted on throttle body intake manifold and operated directly off end of throttle shaft TPS works as a potentiometer varying voltage signal to ECU in direct correlation to angle of throttle plate This signal along with other sensor signals is processed by ECU and compared to internal pre programmed maps to determine required fuel and ignition settings for amount of load Correct position of TPS is established and set at factory Do not loosen TPS or alter mounting position unless absolutely required by fault code diagnosis or throttle shaft service If TPS is loosened or repositioned appropriate TPS Initialization Procedure must be performed to reestablish baseline relationship between ECU and TPS Engine oil temperature sensor is used by system to help determine fuel requirements for starting a cold engin
30. manifold Mount main control bracket to cylinder heads with four screws Torque screws to 10 7 N m 95 in Ib into new holes or 7 3 N m 65 in Ib into used holes 5 Connect dampening spring to throttle lever Connect governor spring from throttle control bracket to appropriate governor lever hole Install Lower Crankshaft Pulley Pulley Adapter and Cooling Fan Assembly NOTE Do not assemble lower pulley with belt between pulley halves as pinching of belt or damage to pulley can occur 1 Make sure shoulder of flywheel hub and adjacent face surface are clean and free of any nicks or damage 2 Install crankshaft pulley adapter onto flywheel hub so offset for pulley is out and holes are aligned Make sure adapter rests squarely on face of flywheel KohlerEngines com 87 Reassembly 3 Assemble front and rear pulley halves placing shims as indicated a For a new belt Assemble with 2 or 3 shims External Engine Components between pulley halves and remaining shim if any on outside front of outer pulley half b For a used belt Assemble with 2 shims between pulley halves and remaining shim s on outside front of outer pulley half Install and snug pulley assembly Final belt tension and pulley assembly will be made after fan upper pulley assembly is installed 4 Install upper fan mounting bracket to intake manifold with screws Torque M6 Screws to 7 3 N m 65 in Ib M8 Screws to 24 4 N m 216 in
31. mm 0 2744 0 2751 in Valve Guide Reamer Size Standard 7 048 mm 0 2775 in 0 25 mm O S 7 298 mm 0 2873 in Intake Valve Lift 8 88 mm 0 3496 in Exhaust Valve Lift 8 88 mm 0 3496 in Nominal Valve Seat Angle Exhaust Valve Guide I D New 7 038 7 058 mm 0 2771 0 2779 in Max Wear Limit 7 159 mm 0 2819 in gt Values are in Metric units Values in parentheses are English equivalents Measure 6 mm 0 2362 in above bottom of piston skirt at right angles to piston pin 10 KohlerEngines com 66 690 07 Rev B Specifications GENERAL TORQUE VALUES English Fastener Torque Recommendations for Standard Applications Bolts Screws Nuts and Fasteners Assembled Into Cast Iron or Steel Grade 2 or 5 Fasteners O Into Aluminum 3 8 16 3 8 24 Noncritical Fasteners Into Aluminum Tightening Torque N m ft Ib 10 21 7 16 27 1 20 47 5 35 66 4 49 81 4 60 M12 36 6 27 47 5 35 82 7 61 116 6 86 139 7 103 M14 58 3 43 76 4 56 131 5 97 184 4 136 219 7 162 Torque Conversions N m in Ib x 0 113 in Ib N m x 8 85 N m ft Ib x 1 356 ft Ib N m x 0 737 66 690 07 Rev B KohlerEngines com 11 Tools and Aids Certain guality tools are designed to help you perform specific disassembly repair and reassembly procedures By using these tools you can properly service engines easier faster and safer In addition you ll increase your service capabilities and customer satisfactio
32. open or shorted Vehicle Wiring Harness Related e Broken or shorted wire in harness Power lead to MIL open or shorted ECU Related e Circuit controlling lamp damaged 42 KohlerEngines com Code 56 Component Fuel pump relay circuit open shorted to ground or shorted to battery Fault Fuel pump ignition coils and fuel injectors will not function because fuel pump relay circuit is either open shorted to ground or may be ON continuously if shorted to battery Condition Engine will not run or fuel pump will continue to run when switch is off Conclusion Fuel Pump Relay Related e Bad fuel pump relay Primary side open or shorted Fuel Pump Related e Fuel pump open or shorted internally Engine Wiring Harness Related e Fuel pump fuse F1 open e Broken or shorted wire in harness ECU pin 28 to fuel pump relay pin 86 Ignition switch to fuel pump relay pin 85 ECU Related e Circuit controlling fuel pump relay damaged Code 61 Component 4 amp Faut O Condition Denotes end of fault codes If signaled first no other fault codes are present Conduson SSS Troubleshooting Flow Chart Following flow chart provides an alternative method of troubleshooting EFI system Chart will enable you to review entire system in about 10 15 minutes Using chart accompanying diagnostic aids listed after chart and any signaled fault codes you should be able to quickly locate any problems wi
33. or fuel pick up dirty clogged or restricted Speed sensor malfunction Stale fuel Low system voltage Bad spark plug s or coil s Base ignition timing incorrect ngine starts hard or fails to start when warm Code 42 5 e Insufficient fuel system pressure e Engine Coolant Temperature sensor faulty e Fuel injector s leaking e Fuel injector s fuel filter fuel line or fuel pick up dirty restricted Low fuel pressure Wrong grade of fuel Bad spark plug s or coil s Low system voltage Speed sensor problem Base ignition timing problem Engine stalls or idles roughly Code 22 31 34 42 43 51 52 e Vacuum intake air leak e Fuel injector s fuel filter fuel line or fuel pick up dirty clogged restricted Insufficient fuel pressure delivery Engine Coolant Temperature sensor faulty TPS faulty or TPS Initialization Procedure incorrect Leaking fuel injector O rings Bad spark plug s or coil s Engine idles too fast after full warm up e Throttle linkage binding or not returning to idle position e Idle speed adjustment incorrect e Vacuum intake air leak e Leaking fuel injector O rings injector to manifold e Engine Coolant Temperature sensor faulty e TPS faulty or TPS Initialization Procedure incorrect e Base ignition timing incorrect 66 690 07 Rev B EFI System Engine misses hesitates or stalls under load Code 22 31 34 43 44 51 52 e Fu
34. path back through exhaust system engine and mounting sensor is grounded through its shell b If continuity is indicated go to step 6 6 With key switch in ON RUN position using a high impedance voltmeter check voltage from wiring harness oxygen sensor connector to 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 black voltmeter lead to negative post of battery to be certain of a good ground If voltage is still not correct ECU is probably bad b If voltage readings are correct clear fault codes and run engine to check if any fault codes reappear To Replace Oxygen Sensor 1 Disconnect oxygen sensor connector from wiring harness 2 Loosen and remove oxygen sensor from exhaust manifold muffler assembly 66 690 07 Rev B 3 Apply anti seize compound sparingly to threads of new oxygen sensor if none already exists DO NOT get any on tip as it will contaminate sensor Install sensor and torque to 50 60 N m 37 44 ft Ib 4 Reconnect lead to wiring harness connector Make sure it can not contact hot surfaces moving parts etc 5 est run engine ELECTRICAL RELAY A malfunctioning relay can result in starting or operating difficulties Relay and related wiring can be tested as follows 1 Disconnect relay connector plug from relay 2 Connect black lead of VOA meter to a chassis ground location Connect red lead to 86 term
35. plate restricting flow of fuel resulting in a poor spray pattern Some contributing factors 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 replaced Additives and higher grades of fuel can be used as a preventative measure if clogging has been a problem NOTE Do not ground coils with ignition ON as they may overheat or spark 66 690 07 Rev B EFI System IGNITION SYSTEM A high voltage solid state battery ignition system is used with EFI system ECU controls ignition output and timing through transistorized control of primary current delivered to coils Based on input from speed sensor ECU determines correct firing point for speed at which engine is running At proper instant it releases flow of primary current to coil Primary current induces high voltage in coil secondary which is then delivered to spark plug Each coil fires every revolution but every other spark is wasted Except for removing spark plug lead by unscrewing it from secondary tower no coil servicing is possible If a coil is determined to be faulty replacement is necessary An ohmmeter may be used to test wiring and coil windings Testing 1 Disconnect main harness connector from ECU Locate pins 30 and 81 in 32 pin connector 2 Disconnect connector from relay and locate terminal 87 in
36. screen spark arrestor if equipped Clean or replace as needed Repair or replace any other damaged restricted muffler or exhaust system parts 66 690 07 Rev B KohlerEngines com 17 Troubleshooting COMPRESSION TEST For Command Twins A compression test is best performed on a warm engine Clean any dirt or debris away from base of spark plug s before removing them Be sure choke is off and throttle is wide open during test Compression should be at least 160 psi and should not vary more than 15 between cylinders All other models These engines are equipped with an automatic compression release ACR mechanism It is difficult to obtain an accurate compression reading because of ACR mechanism As an alternative use cylinder leakdown test described below CYLINDER LEAKDOWN TEST A cylinder leakdown test can be a valuable alternative to a compression test By pressurizing combustion chamber from an external air source you can determine if valves or rings are leaking and how badly Cylinder leakdown tester is a relatively simple inexpensive leakdown tester for small engines This tester includes a quick connect for attaching adapter hose and a holding tool 1 Run engine for 3 5 minutes to warm it up 2 Remove spark plug s and air filter from engine 3 Rotate crankshaft until piston of cylinder being tested is at top dead center TDC of compression stroke Hold engine in this position while testing Holding tool supplied
37. using wire feeler gauge Adjust gap see specification table for adjustment 2 Install plug into cylinder head 3 Torque plug to 20 ft Ib 27 N m KohlerEngines com 85 Reassembly External Engine Components e Kap wd ae Pa Gc sii Le E JU wi wii D e e Breather Hose A B Ef meme Ir T NN EN M Oil Sentry Breather Cover D Fan Mounting n ul rm Fan Belt J Bearing K Pulley Pulley Half Spacer Shims N Adapter Torque Sequence 3 Install breather reed and breather reed retainer onto Install Reed and Breather Cover Assembly crankcase and secure with screw Hold assembly in Make sure sealing surfaces of crankcase and line when tightening Torque screw to 3 9 N m breather cover are clean and free of all old gasket 35 in Ib material Clean with an aerosol type gasket remover or cleaning solvent DO NOT scrape surfaces as this 4 Install breather filter into cavity in crankcase can result in leakage 5 Carefully install breather cover gasket and breather 2 Check to make sure there are no nicks or burrs on cover onto crankcase sealing surfaces 6 Install and torque four breather cover screws to 7 3 N m 65 in Ib in sequence shown 86 KohlerEngines com 66 690 07 Rev B Z Install pipe plug or Oil Sentry switch as equipped into tapped breather port if removed earlier Apply pipe sealant with Teflon Loctite PST 592 Thread Sealant or equi
38. with Thermostat Housing cooling fan is not cracked or missing any blades Check e Radiator Cap that fan belt and two drive pulleys are in good condition e Cooling Fan Belt and Drive Pulleys and proper belt tension is present e Overflow Reservoir Service e Crankcase and Heads with Integral Cooling Passages Um screen vertically to remove for cleaning servicing Clean screen and cooling fins of radiator with a soft Operation brush or blow out using clean compressed air To avoid KLL damage to screen and cooling fins do not use a high pressure washer to clean Cooling System Maintenance and Service Engine coolant is pumped through cooling system by a pump belt driven off camshaft Coolant coming out of pump is divided and moves simultaneously through separate circuits within each head and corresponding sides of crankcase As coolant moves through these Overflow Reservoir Details passages it absorbs heat from engine parts After traveling through engine coolant from two separate circuits merges and moves through intake manifold to lower side of thermostat During warm up thermostat is closed preventing circulation through radiator Coolant circulates through engine only and is returned to pump via bypass hose When engine heat brings coolant up to a temperature of 79 4 C 175 F thermostat will begin to open allowing coolant to circulate through upper hose to radiator Thermostat is completely open at 90 5 C 195 F allowing f
39. with tester can be used if PTO end of crankshaft is accessible Lock holding tool onto crankshaft Install a 3 8 in breaker bar into hole slot of holding tool so it is perpendicular to both holding tool and crankshaft PTO If flywheel end is more accessible use a breaker bar and socket on flywheel nut screw to hold it in position An assistant may be needed to hold breaker bar during testing If 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 engine cannot rotate off of TDC in either direction Install adapter into spark plug hole but do not attach it to tester at this time Turn regulator knob completely counterclockwise Connect an air source of at least 50 psi to tester Turn regulator knob clockwise increase direction until gauge needle is in yellow set area at low end of scale Connect tester quick connect to adapter hose While firmly holding engine at TDC gradually open tester valve Note gauge reading and listen for escaping air at combustion air intake exhaust outlet and crankcase breather E SLE s Condition Conclusion Gauge reading in low green zone Gauge reading in moderate yellow zone Engine is still usable but there is some wear present Customer should start planning for overhaul or replacement Gauge reading in high red zone Rings and or cylinder have considerable wear Engine should be reconditioned or replaced
40. 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 0 94615 0 98425 mm 0 03725 0 03875 in 0 99695 1 03505 mm 0 03925 0 04075 in Gray Black Oil Pump Assembly Oil pump is mounted to inside of closure plate If service was required and oil pump was removed refer to assembly procedures under Oil Pump Assembly in Reassembly Governor Assembly Governor assembly is located inside closure plate If service was required and governor was removed refer to assembly procedures under Governor Assembly in Reassembly Thrust Bearing Washer and Shim Some specifications use a thrust bearing thrust washer and shim to control end play of crankshaft If these items were noted during disassembly make sure they were reinstalled in proper sequence as illustrated A different procedure must be followed to check and adjust crankshaft end play on these models Race for thrust bearing presses loosely into closure plate If it is not already installed push it into crankshaft bore inside closure plate Pack thrust bearing with heavy grease and stick bearing into race Wipe some grease on face of thrust washer and stick it onto thrust bearing Wipe some grease on face of original shim and stick it onto thrust washer Install closure plate onto crankcase without applying RTV sealant and secure it with only two or three fasteners at thi
41. 20 25 in Ib 4 lf removed mount rectifier regulator to plate with two screws and attach connector plug Install Muffler 1 Install new exhaust gaskets and attach muffler and mounting hardware Torque screws to 9 9 N m 88 in Ib 2 Install nuts to exhaust studs Torque nuts to 24 4 N m 216 in Ib 90 KohlerEngines com Install Oil Filter and Fill Crankcase with Oil NOTE Make sure both oil drain plugs are installed and torqued to specifications to prevent oil leakage 1 Install oil drain plug s Torque plug s to 13 6 N m 10 ft Ib If oil drain valve is used make sure valve body is closed and cap is on 2 Place new filter in shallow pan with open end up Fill with new oil until oil reaches bottom of threads Allow 2 minutes for oil to be absorbed by filter material 3 Apply a thin film of clean oil to rubber gasket on oil filter 4 Referto instructions on oil filter for proper installation 5 Fill crankcase with new oil Level should be at top of indicator on dipstick 6 Reinstall oil fill cap dipstick and tighten securely Install Coolant 1 Use equal parts of ethylene glycol antifreeze and water only Distilled or deionized water is recommended especially in areas where water contains a high mineral content Propylene glycol based antifreeze is not recommended 2 Fill cooling system through radiator with coolant mix Allow coolant to drain into lower areas Fill overflow reservoi
42. 64 Injector 2 Short Circuito Ground xl P0265 Injector 2 Short Circuitto Battery xl P1657 56 P1651 MLtamp Open Grit NI 55 P1652 MIL Lamp Short Cicuitto Ground Jv O 56 P1653 MIL Lamp Short Circuit to Batey xl P1231 Pump Relay Open Grit LY 56 P1232 Pump Relay Short Circuitto Grund LY 56 P1233 Pump Relay Short Circuitto Batey xl 58 P1480 Cooling Fan Driver Circuit Open ONO 58 P1481 Cooling Fan Driver Circuit Shorten to Grund n O 58 P1482 Cooling Fan Driver Circuit Shorten to tags NI 61 EndoCodeTansmsson AI O 4 Will not blink out MIL Lamp is always switched OFF when failure is SPORADIC 66 690 07 Rev B KohlerEngines com 37 EFI System DIAGNOSTIC CODE SUMMARY Code 21 Engine Speed Sensor Conclusion 38 Code 22 Throttle Position Sensor TPS ECU receiving inconsistent tooth count signals from speed sensor Possible misfire as ECU attempts to resynchronize during which time fuel and spark calculations are not made Engine Speed Sensor Related e Sensor connector or wiring e Sensor loose or incorrect air gap e Flywheel key sheared Condition Speed Sensor Ring Gear Related Conclusion e Damaged teeth e Varying gap gear loose out of alignment Engine Wiring Harness Related e Pin circuits 9 and or 10 wiring or connectors e Shielding for pin circuits 9 and or 10 damaged or not properly grounded e Poor or
43. 9 and 10 pin terminals A resistance value of 750 1000 at room temperature 20 C 68 F should be obtained If resistance is correct check mounting air gap toothed ring gear damage runout etc and flywheel key 6 Disconnect speed sensor connector from wiring harness It is connector with one heavy black lead Viewing connector as shown dual aligning rails on top test resistance between terminals indicated A reading of 750 1000 O should again be obtained 7 If resistance is incorrect remove screw securing sensor to mounting bracket and replace sensor a If resistance in step 5 was incorrect but resistance of sensor alone was correct test main harness circuits between sensor connector terminals and corresponding pin terminals in main connector Correct any observed problem reconnect sensor and perform step 5 again p Throttle Position Sensor TPS A Throttle Valve Shaft B Resistor Track k fo imu Wiper Connection 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 TPS it can be tested as follows 1 Counting number of turns back out idle speed adjusting screw counterclockwise until throttle plates can be closed completely 2 Disconnect main harness connector from ECU but leave TPS mounted to throttle body manifold 3 Connect Red positive ohmmeter lead to 8 pin terminal an
44. 982 7 000 mm 0 2749 0 2756 in INTAKE VALVE EXHAUST INSERT INTAKE INSERT Exhaust 89 32 987 33 013 mm 1 2987 1 2997 in 6 5 mm 0 2559 in 7 038 7 058 mm 0 2771 0 2779 in 29 37 29 63 mm 1 1563 1 1665 in 45 1 5 mm 0 0591 in 6 970 6 988 mm 0 2744 0 2751 in 3 With keepers taken out following items can be removed e valve spring retainers e valve springs e valve spring caps e intake and exhaust valves e valve stem seals intake valve only 4 Repeat above procedure for other cylinder head Do not interchange parts from one cylinder head with parts from other cylinder head After cleaning check flatness of cylinder head and corresponding top surface of crankcase using a surface plate or piece of glass and feeler gauge Maximum allowable out of flatness is 0 076 mm 0 003 in Carefully inspect valve mechanism parts Inspect valve springs and related hardware for excessive wear or distortion Check valves and valve seat area or inserts for evidence of deep pitting cracks or distortion Check clearance of valve stems in guides 66 690 07 Rev B Hard 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 valves first After removal clean valve heads faces and stems with a power wire brush Then carefully inspect each valve for defects such as a warped head exce
45. Aid 7 IGNITION SYSTEM no spark Possible causes e Spark plug e Plug wire e Coil e Coil circuit s Circuits 30 31 65 66 relay and relay circuit 30 e ECU grounds e ECU Diagnostic Aid 8 FUEL SYSTEM ELECTRICAL no fuel delivery Possible causes No fuel Air in fuel rail Fuel valve shut off Fuel filter line plugged Injector circuit s Circuits 14 15 45 and 4A Injector ECU grounds ECU Diagnostic Aid 9 FUEL SYSTEM fuel pressure Possible causes for low fuel system pressure Low fuel Fuel filter plugged Fuel supply line plugged Pressure regulator Fuel pump Possible causes for high fuel system pressure e Pressure regulator e Fuel return line plugged or restricted 66 690 07 Rev B Diagnostic Ad 10 BASIC ENGINE cranks but will not run Possible causes e Refer to basic engine troubleshooting charts within service manual Common Complaints Problems Following are some of most common complaints or problems reported by customers For each problem you will find a list of most likely causes or areas to be investigated Always start by checking if there are any stored fault codes to guide you in right direction Engine starts hard or fails to start when cold Code 31 42 51 52 56 Fuel pump or relay not activating operational Engine Coolant Temperature sensor faulty Fuel pressure insufficient incorrect Fuel injector s leaking Fuel injector s fuel filter fuel line
46. D2 Condition or Failure Description MIL Code P Code Illuminated 58 P1480 Cooling Fan Driver Circuit Open 1481 1482 58 58 Cooling Fan Driver Circuit Shorten to Ground Cooling Fan Driver Circuit Shorten to Voltage End of Code Transmission NOTE 1 02 Sensor Short to Battery diagnostic detection is disabled with SAS fuel cutoff calibrated out 2 System too Lean used to be O2 Sensor Short to Ground P0131 3 System too Rich used to be O2 Sensor Control at Lower Limit P0019 NoRPMSga y 21 POS Loss of Synchronization Y 22 P0129 TPS Open or Short CircuittoGround Y 22 POU3 TPS Short CrouittoBattery e Y 23 Na Y a Engine Speed Saa Y 4 32 P0134 02 Sensor Circuit No Activity Detected Y P0020 02 Sensor ControlatUpperlimt nr 34 POI Maximum Adaption LimitReached Y 34 P0172 Minimum Adaption Limit Reached xl 42 ma Temperature Sensor Circuit Shorted to Ground v 42 Pons Temperature Sensor Circuit Open Circuit or Shortto Batey v P1670 Failure Completing Autoleam TPS Offset below minimum allowable imt Y 44 P1671 Failure Completing Autoleam TPS Offset above maximum allowable im Y P1260 Tree Geen Grit LY a P0264 Injector 1 Shori Circuito Ground IN 51 P0262 injector 1 Short Circuitto Batey xl 52 P1263 Injector2 Open Circuit LY lo 52 P02
47. FER TO DIAGNOSTIC AID 10 Yes BASE ENGINE Operate for an appropriate period of time based upon original fault codes 66 690 07 Rev B KohlerEngines com 43 EFI System Flow Chart Diagnostic Aids Diagnostic Aid 1 SYSTEM POWER MIL does not illuminate when key is turned ON Possible causes Battery Main system fuse MIL light bulb burned out MIL electrical circuit problem Pin circuits 29 and 84 Ignition switch Permanent ECU power circuit problem Pin circuit 1 Switched ECU power circuit problem Pin circuit 2 ECU grounds ECU Diagnostic Aid 2 FAULT CODES Refer to detailed fault code listing before flow chart and servicing information for respective components e Code 21 Engine Speed Synchronization e Code 22 Throttle Position Sensor TPS e Code 23 Engine Control Unit ECU e Code 31 Oxygen Sensor e Code 32 Oxygen Sensor e Code 33 Fuel System temporary adaptation factor e Code 34 Fuel System permanent adaptation factor e Code 42 Engine Coolant Temperature Sensor e Code 43 TPS Auto Learn Initialization Function Below Min Limit e Code 44 TPS Auto Learn Initialization Function Above Max Limit e Code 51 Injector 1 e Code 52 Injector 2 e Code 55 MIL Diagnostic Light e Code 56 Pump Relay e Code 61 End of Fault Blink Code Transmission Diagnostic Aid 3 RUN ON MIL remains ON while engine is running Possible causes e Fault codes which turn on MI
48. FilCap D OilFilter E Oil Drain Plug 46 KohlerEngines com 66 690 07 Rev B OIL RECOMMENDATIONS Refer to Maintenance CHECK OIL LEVEL NOTE To prevent extensive engine wear or damage never run engine with oil level below or above operating range indicator on dipstick Ensure engine is cool Clean oil fill dipstick areas of any debris 1 Remove dipstick wipe oil off 2 Reinsert dipstick into tube press completely down 3 Remove dipstick check oil level Level should be at top of indicator on dipstick 4 If oil is low on indicator add oil up to top of indicator mark 5 Reinstall and secure dipstick CHANGE OIL AND FILTER Change oil while engine is warm 1 Clean area around oil fill cap dipstick drain plug oil drain valve Remove drain plug and oil fill cap dipstick Allow oil to drain completely 2 Clean area around oil filter Place a container under filter to catch any oil and remove filter Wipe off mounting surface Reinstall drain plug Torque to 13 6 N m 10 ft Ib 3 Place new filter in shallow pan with open end up Fill with new oil until oil reaches bottom of threads Allow 2 minutes for oil to be absorbed by filter material 4 Apply a thin film of clean oil to rubber gasket on new filter 5 Refer to instructions on oil filter for proper installation 6 Fill crankcase with new oil Level should be at top of indicator on dipstick OIL SENTRY if equipped This switch is desig
49. Ib By pass hose and wires must be positioned within cutout in intake manifold Be careful not to pinch harness wires between bracket and intake manifold when tightening 5 If disassembled reassemble fan and pulley assembly as shown Make sure one flat washer is placed between bearings in hub Other washer is located under front nut Torque fan pulley nub mounting screws to 6 8 N m 60 in Ib 6 If fan shaft was removed from upper mounting bracket apply Loctite 242 to rear threads Install and torque rear nut to 15 8 N m 140 in Ib Install fan and pulley assembly onto fan shaft and upper mounting bracket 7 Apply Loctite 242 to front threads of fan shaft Install flat washer and nut to secure Torque nut to 15 8 N m 140 in Ib 8 Carefully work belt into place on pulleys Check belt tension There should be no more than 9 53 Install Air Cleaner Assembly 12 7 mm 3 8 1 2 belt deflection per side with 10 Ibs of applied tension If belt tension is low remove belt and relocate a A Radiator Assembly an Cleaner Assembly shim from between pulley halves to outside front Ignition Module Mounting Bracket Reinstall belt and recheck tension Repeat E SS D GE procedure until correct tension is reached if shims E Adapter Plate F ECU have all been moved to outside and belt is still too loose replace belt Install a new elbow adapter gasket onto intake manifold adapter When prop
50. KOHLER Aegis LH775 Service Manual IMPORTANT Read all safety precautions and instructions carefully before operating equipment Refer to operating instruction of equipment that this engine powers Ensure engine is stopped and level before performing any maintenance or service NO Safety 3 Maintenance 5 Specifications 12 Tools and Aids 15 Troubleshooting 19 Air Cleaner Intake 20 Electronic Fuel Injection EFI System 46 Lubrication System 48 Electrical System 52 Starter System 56 Cooling System 60 Disassembly Inspection and Service 77 Reassembly 66 690 07 Rev B KohlerEngines com Safety SAFETY PRECAUTIONS AA WARNING A hazard that could result in death serious injury or substantial property damage AA CAUTION A hazard that could result in minor personal injury or property damage NOTE is used to notify people of important installation operation or maintenance information warninc Explosive Fuel can cause fires and severe burns Do not fill fuel tank while engine is hot or running 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 Spilled fuel could ignite if it comes in contact with hot parts or sparks from ignition Never use gasoline as a cleaning agent Rotating Parts can cause severe injury Stay away while engine is in operation Keep han
51. L when engine is running e Code 21 Engine Speed Synchronization e Code 22 Throttle Position Sensor TPS e Code 23 Engine Control Unit ECU e Code 31 Oxygen Sensor shorted o init 34 Fuel System permanent adaptation at limit e Code 42 Engine Coolant Temperature Sensor e Code 43 TPS Auto Learn Initialization Function Below Min Limit e Code 44 TPS Auto Learn Initialization Function Above Max Limit e Code 51 Injector 1 e Code 52 Injector 2 e Code 55 MIL Diagnostic Light e Code 56 Pump Relay e MIL circuit grounded between light and ECU Pin circuit 29 e ECU NOTE MIL diagnostic light used must be a 1 4 watt incandescent lamp An LED style light will stay on continuously dim and should not be used 44 KohlerEngines com Diagnostic Aid 4 SPEED SENSOR MIL does not turn off during cranking Indicates ECU is not receiving a signal from speed sensor Possible causes e Speed sensor e Speed sensor circuit problem Pin circuits 9 and 10 e Speed sensor toothed wheel air gap e Toothed wheel e Flywheel key sheared e ECU Diagnostic Aid 5 FUEL PUMP fuel pump not turning on Possible causes e Fuel pump fuse e Fuel pump circuit problem Circuits 30 87 and relay e Fuel pump Diagnostic Aid 6 RELAY relay not operating Possible causes Safety switches circuit s problem Circuit 25 Relay circuit s problem Circuits 28 85 30 and 87 Relay ECU grounds ECU Diagnostic
52. Mounting plate for rectifier regulator will become detached when LH screws are removed Do not lose small spacers located within holes of lower cover Clips are used on some models instead of nuts 62 KohlerEngines com 2 Disconnect upper radiator hose from radiator and lower radiator hose from inlet of water pump 3 Remove screws securing two upper radiator supports to air cleaner mounting bracket 4 Carefully tilt pull radiator forward slightly to clear fan and lift complete assembly out of lower mounting bracket 5 Remove four screws securing LH and RH side mounting brackets to crankcase Pull complete mount assembly forward to remove 6 Further disassembly for component servicing may be performed as required Remove Air Cleaner Assembly 1 Remove screws securing elbow adapter and gasket to intake manifold 2 Disconnect breather hose from intake manifold 3 Remove upper valve cover mounting screws on each side which also secure main mounting bracket for air cleaner 4 Disconnect connector plug from rectifier regulator Remove screw securing rectifier regulator ground wire to intake manifold Rectifier regulator can remain secured to bracket 5 Liftair cleaner mounting bracket assembly off engine Remove Throttle and Choke Controls Control Panel Details Control Panel B Choke Lever E Governor Spring 1 Remove screws securing main control bracket to cylinder heads 2 Mark hole l
53. NCE SCHEDULE Every 200 Hours e Change oil and oil filter Lubrication System Every 200 Hours e Replace fuel filter Every 250 Hours e Replace air cleaner element and check inner element Air Cleaner Intake Every 500 Hours e Replace air cleaner inner element Air Cleaner Intake Every 500 Hours e Replace spark plugs and set gap Electrical System Every 1000 Hours e Change engine coolant Cooling System Every 1500 Hours e Replace unique Electronic Fuel Injection EFI fuel filter Perform these procedures more frequently under severe dusty dirty conditions REPAIRS SERVICE PARTS Kohler genuine service parts can be purchased from Kohler authorized dealers Find your local Kohler Engines dealer at KohlerEngines com or call 1 800 544 2444 U S A and Canada LA 66 690 07 Rev B KohlerEngines com Maintenance OIL RECOMMENDATIONS We recommend use of Kohler oils for best performance Other high quality detergent oils including synthetic of API American Petroleum Institute service class SJ or higher are acceptable Select viscosity based on air temperature at time of operation as shown in table below Explosive Fuel can cause fires and severe burns Do not fill fuel tank while engine is hot or running 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 Sp
54. OT stop if equipped ELECTRICAL SYSTEM NOTE When performing voltage or continuity tests avoid putting excessive pressure on or against connector pins Flat pin probes are recommended for testing to avoid spreading or bending terminals 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 operation of voltage sensitive components such as 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 that EF l related problems are more often caused by wiring harness or connections than by EFI components Even small amounts of corrosion or oxidation on terminals can interfere with milliamp currents used in system operation Cleaning connectors and grounds will solve problems in many cases In an emergency situation simply disconnecting and reconnecting connectors may clean up contacts enough to restore operation at least temporarily 66 690 07 Rev B If a fault code indicates a problem with an electrical component disconnect ECU connector and test for continuity between component connector terminals and corresponding termina
55. S AA CAUTION p Electrical Shock can cause injury Gy Do not touch wires while engine is running Spark Plug Component and Details A WieGauge B Spark Plug Ground Electrode D Gap NOTE Do not clean spark plug in a machine using abrasive grit Some grit could remain in spark plug and enter engine causing extensive wear and damage Engine misfire or starting problems are often caused by a spark plug that has improper gap or is in poor condition Engine is equipped with following spark plugs 0 76 mm 0 03 in Thread Size 19 1 mm 3 4 in 15 9 mm 5 8 in Refer to Maintenance for Repairs Service Parts Service Clean out spark plug recess Remove plug and replace 1 Check gap using wire feeler gauge Adjust gap to 0 76 mm 0 03 in 2 Install plug into cylinder head 3 Torque plug to 27 N m 20 ft Ib 48 KohlerEngines com Inspection Inspect each spark plug as it is removed from cylinder head Deposits on tip are an indication of general condition of piston rings valves and carburetor Normal and fouled plugs are shown in following photos Normal Plug taken omia an engine operating under normal conditions will have light tan or gray colored deposits If center electrode is not worn plug can be set to proper gap and reused Worn On a worn plug center electrode will be rounded and gap will be greater than specified gap Replace a worn spark plug immediate
56. aft oil seal 5 Install camshaft oil seal to a depth of 1 0 1 5 mm 0 039 0 059 in below top of seal bore Do not bottom seal in bore or oil passage may be obstructed Install Governor Cross Shaft 1 Lubricate governor cross shaft bearing surfaces in crankcase with engine oil Apply a small amount of grease to lips of oil seal 2 Slide small lower washer onto governor cross shaft and install cross shaft from inside of crankcase 3 Install nylon washer onto governor cross shaft then start push on retaining ring Hold governor shaft up in position then place a 0 25 mm 0 010 in feeler gauge on top of nylon washer and push retaining ring down shaft to secure Remove feeler gauge which will have established proper end play 4 Pivot governor cross shaft so bottom end faces cylinder 1 side Install Crankshaft NOTE Apply cellophane tape over crankshaft keyway to prevent cutting oil seal during installation 1 Lightly lubricate lips of crankshaft seal with grease 2 Carefully slide flywheel end of crankshaft into crankcase through oil seal Install Connecting Rods with Pistons and Rings Piston Connecting Rod Details Cylinder4 B Oylinder2 78 KohlerEngines com NOTE Cylinders are numbered on crankcase Make sure to install piston connecting rod and end cap into its appropriate cylinder bore as previously marked at time of disassembly Do not mix end caps and connecting rods NOTE Proper orient
57. amaged replace oil pump assembly and or O ring Check oil pickup screen for damage or restriction replace if necessary Reassembly 1 Lubricate outer gerotor gear with oil Install outer gerotor gear through shaft of oil pump around inner gerotor gear Matching molding dots on inner and outer gerotor gears is not necessary and will not affect oil pump efficiency 2 Reinstall ball then spring into pressure relief hole in closure plate 3 Reinstall O ring into groove in closure plate make sure it is fully seated in groove 4 Install oil pump inserting center shaft into corresponding recess in closure plate Apply consistent downward pressure to oil pump cover compressing oil pressure relief spring and start screws Secure oil pump by torquing screws in no specific sequence to 7 9 N m 70 in Ib 5 After torquing rotate gear and check for freedom of movement Make sure there is no binding If binding Occurs loosen screws reposition pump retorque screws and recheck movement Remove Camshaft 1 Remove camshaft and shims Remove Connecting Rods with Pistons and Rings NOTE If a carbon ridge is present at top of either cylinder bore use a ridge reamer tool to remove it before attempting to remove piston Cylinders are numbered on crankcase Use numbers to mark each end cap and connecting rod piston assembly for reassembly later Do not mix end caps and connecting rods 1 Remove screws securing closest connec
58. and replace temperature sensor Use pipe sealant with Teflon on threads Cooling System Leakage Test A pressure test of cooling system can be performed as a relatively simple means of determining whether cooling system may contain a leak A pump pressure type cooling system tester with appropriate 45 mm adapter may be used to check cooling system and radiator cap Test Instructions 1 With engine cool carefully remove radiator cap see Pressure Radiator Cap Make sure all parts of cap and adapter are clean Install cap on corresponding adapter and make sure it is completely seated Install adapter onto tester and lock in place 2 Pressurize tester to 15 psi 3 Observe indicated pressure It should hold steady and not decrease or leak down If leakage is detected cap should be replaced If tester pressure is increased to 16 psi or above cap should then bleed off this excess pressure 4 Install and lock system adapter and tester onto neck of cooling system Pressurize tester to 14 15 psi 5 Observe system pressure on gauge Gauge Needle Holds Steady If gauge needle holds steady there should be no serious leaks in system It is however recommended that all connections be checked for overall condition anyway using a flashlight Gauge Needle Drops Slowly If gauge needle drops slowly it indicates presence of a small leak or seepage Check all components and connections for signs of leakage Check condition of
59. ate ground lead connection Make certain connection location is clean and clamp is secure Other lights come on 50 KohlerEngines com 66 690 07 Rev B Troubleshooting Guide 25 Amp Battery Charging System Electrical System NOTE Always zero ohmmeter on each scale before testing to ensure accurate readings Voltage tests should be made with engine running at 3600 RPM no load Battery must be good and fully charged When problems occur in keeping battery charged or battery charges at too high a rate problem can usually be found somewhere in charging system or with battery To test charging system for no charge to battery 1 Insert an ammeter in B lead from rectifier regulator With engine running at 3600 RPM and B at terminal on rectifier regulator to ground using a DC voltmeter If voltage is 13 8 volts or more place a minimum load of 5 amps turn on lights if 60 watts or more or place a 2 5 ohm 100 watt resistor across battery terminals on battery to reduce voltage Observe ammeter Condition Conclusion Charge rate increases Charging system is OK when load is applied and battery was fully charged Test stator and rectifier Charge rate does not regulator steps 2 and 3 increase when load is applied 2 Remove connector from rectifier regulator With engine running at 3600 RPM measure AC voltage across stator leads using an AC voltmeter Condition Conclusion Voltage is 28 volts or Stator
60. ater pump to crankcase 3 Lift water pump up and carefully work ferruled end of transfer tube out of fitting Remove water pump with transfer tube and hose section attached Remove and discard O ring from within channel of pump housing 4 Inspect and if necessary separate transfer tube and hose section from water pump Remove hose clamps noting their size differences and position of tangs IMPORTANT 90 fitting in crankcase which transfer tube is connected to is sealed and installed at factory in a specific position Do not loosen remove or alter mounted position of this fitting at any time Contact factory service department for specific instructions if fitting is damaged or its mounting is affected in any way Inspection and Service Water Pump Details d mm F W puc d US L _ jE A M F I aa ee ai T ER S HE P E aa Impeller B Drive Pulley Water coolant pump consists of a sealed impeller assembly which includes outer cover and a cogged drive pulley When pump is mounted to crankcase impeller fits into a cast recess and cover seals against an O ring outside perimeter of recess Impeller assembly is not serviceable but it should be inspected for wear or damage 1 Inspect impeller to make sure blades are in good condition and free of any cracks nicks or damage 2 Impeller shaft should rotate smoothly without
61. ation Install silver plated ground screw in its original location normally number 4 or 6 location Torque fasteners in torque sequence shown to 24 4 N m 216 in Ib Install Closure Plate Assembly Install Cylinder Studs Piston Connecting Rod Details HI LNA Stud End with Loctite Dri Loc NOTE Do not reinstall or attempt to reuse any cylinder studs that have been removed Discard any removed stud s and replace with new If any of cylinder studs were removed install new stud s as follows 1 Identify longer threaded end of new stud containing Loctite Dri Loc 2 Tighten nuts together on shorter threaded section with identification mark on end 3 Thread end of stud with Loctite into crankcase until an exposed stud height of 75 mm 2 61 64 in is obtained End with dash mark must be out When threading in studs use a steady tightening motion without interruption until proper height is obtained Frictional heat from engaging threads may otherwise cause locking compound to set up prematurely Remove two nuts 4 Repeat steps 1 3 for each of studs Plated Screw Location RTV silicone sealant is used as a gasket between closure plate and crankcase Always use fresh sealant Using outdated sealant can result in leakage 1 Be sure sealing surfaces have been cleaned and prepared 2 Check to make sure that there are no nicks or burrs on sealing surfaces of closure plate or crankcase 3 A
62. ation of piston connecting rod assemblies inside engine is extremely important Improper orientation can cause extensive wear or damage NOTE Make sure to align chamfer of connecting rod with chamfer of its mating end cap When installed flat faces of connecting rods should face each other Faces with raised rib should be toward outside 1 Stagger piston rings in grooves until end gaps are 120 apart Oil ring rails should also be staggered 2 Lubricate cylinder bore piston and piston rings with engine oil Compress rings of cylinder 1 piston using a piston ring compressor 3 Lubricate crankshaft journals and connecting rod bearing surfaces with engine oil 4 Make sure FLY stamping on pistons is facing towards flywheel side of engine Use a hammer with rubber grip and gently tap piston down into cylinder Be careful that oil ring rails do not spring free between bottom of ring compressor and top of cylinder 5 Guide lower end of connecting rod and rotate crankshaft to join two Install rod cap to connecting rod using screws and torque in increments to 11 3 N m 100 in Ib 6 Repeat above procedure for other connecting rod and piston assembly Install Camshaft 1 Inspect edges of camshaft keyway make sure they are not nicked or burred Use a seal protector 11 16 to prevent damaging seal lips or dislodging inner spring when camshaft is installed Cellophane tape over keyway is also recommended 2 Lubricat
63. ator Drain Plug 1 Ensure engine is cool When radiator is cool to touch slowly loosen radiator cap to first stop and allow any pressure to bleed off Then loosen it fully and remove it Loosen remove radiator drain plug and allow coolant to drain 2 f equipped remove coolant drain plugs located on each side of engine block Drain coolant into a suitable container After coolant has drained completely apply pipe sealant with Teflon Loctite PST 592 or equivalent to threads and reinstall plugs Torque plugs to 36 7 N m 325 in Ib 3 Remove overflow hose from reservoir Unhook inboard retainer and slide reservoir out of supports Pour out contents and wash or clean as required Dispose of all old coolant in accordance with local ordinances 4 Reinstall reservoir cap Do not kink pinch hose o Flush cooling system Flushing Cooling System NOTE To prevent engine damage do not pour water into a hot engine Do not operate engine without coolant With system properly drained 1 Fill cooling system with clean water and a cooling system cleaner recommended for aluminum engines Follow directions on container 2 Reinstall and tighten radiator cap 3 Start and run engine for five minutes or until it reaches operating temperature Stop engine and allow it to cool 66 690 07 Rev B Cooling System 4 Drain cooling system 5 Fill cooling system Filling Cooling System NOTE To prevent engine damag
64. binding or wobbling and there should be no sign that coolant has leaked past shaft to outer surface of cover 3 Check that drive pulley is not cracked or damaged in any way If your inspection causes you to doubt its reliability water pump assembly should be replaced Always use a new O ring whenever water pump is removed Do not reuse old O ring or try to use RTV in its place 66 690 07 Rev B Disassembly Inspection and Service Cylinder Head Components A B Head Hydraulic Lifter bD EI Valve Stem Seal F Valve Spring Cap G Spring H Valve Spring Retainers Wa Valve Spring Keepers J RockerArms K Rocker Arm Pivot Rocker Arm Screw M Valve Cover 2 Remove push rods and mark their location as either Remove Valve Covers OO intake or exhaust and cylinder 1 or 2 Push rods 1 Remove screws from two lower valve cover should always be reinstalled in their original position mounting locations on each side Repeat for opposite cylinder 2 Remove valve covers and valve cover gaskets Note R t d hers f inderhead Aiud on which side oil fill or fuel pump is located for SOY E AUS AA AS er eer ee der Carefully remove cylinder heads and head gaskets correct reassembly later 5 Remove hydraulic lifters using a hydraulic lifter Remove Spark Plugs removing tool do not use a magnet Mark them similar to push rods intake or exhaust and cylinder 1 b ka E EES or 2 Hydraulic lifters should always be reinstalled in
65. brush holder assembly so holes in metal mounting clips are up out c Install brush springs and snap on retainer caps d Hold starter assembly vertically on end housing and carefully place tool with extension and assembled original brush holder assembly onto end of armature shaft Slide brush holder assembly down into place around commutator install positive brush lead grommet in cutout of frame Install end cap onto armature and frame aligning thin raised rib in end cap with corresponding slot in grommet of positive brush lead 66 690 07 Rev B Starter System 12 Install thru bolts and brush holder mounting screws Torque bolts to 5 6 9 0 N m 49 79 in Ib and brush holder mounting screws to 2 5 3 3 N m 22 29 in Ib 13 Hook plunger behind upper end of drive lever and install spring into solenoid Insert mounting screws through holes in drive end cap Use these to hold solenoid gasket in position then mount solenoid Torque screws to 4 0 6 0 N m 35 53 in Ib 14 Connect positive brush lead bracket to solenoid and secure with nut Torque nut to 8 11 N m 71 97 in Ib Do not overtighten Solenoid Tests NOTE DO NOT leave 12 volt test leads connected to solenoid for any time over what is necessary for performing each of individual tests Internal damage to solenoid may occur Disconnect all leads from solenoid including positive brush lead attached to lower stud terminal Remove mounting hardware an
66. case overfilled e Incorrect oil viscosity type e Worn cylinder bore e Worn or broken piston rings e Worn valve stems valve guides Oil Leaks from Oil Seals Gaskets e Breather reed broken Loose or improperly torqued fasteners Piston blow by or leaky valves Restricted exhaust 16 KohlerEngines com Clogged broken or inoperative crankcase breather EXTERNAL ENGINE INSPECTION NOTE It is good practice to drain oil at a location away from workbench Be sure to allow ample time for complete drainage Before cleaning or disassembling engine make a thorough inspection of its external appearance and condition This inspection can give clues to what might be found inside engines and cause when it is disassembled e Check for buildup of dirt and debris on crankcase cooling fins grass screen and other external surfaces Dirt or debris on these areas can cause overheating e Check for obvious fuel and oil leaks and damaged components Excessive oil leakage can indicate a clogged or inoperative breather worn or damaged seals or gaskets or loose fasteners e Check air cleaner cover and base for damage or indications of improper fit and seal e Check air cleaner element Look for holes tears cracked or damaged sealing surfaces or other damage that could allow unfiltered air into engine A dirty or clogged element could indicate insufficient or improper maintenance e Check carburetor throat for dirt Dirt in thr
67. ch housing and rotating pinion Pinion should rotate in only 1 direction Brushes and Springs Detail Wear Limit Length Inspect both springs and brushes for wear fatigue or damage Measure length of each brush Minimum length for each brush is 7 6 mm 0 300 in Replace brushes if they are worn undersize or condition is questionable Armature Components and Details B Commutator OD B Mica Insulation KohlerEngines com 53 Starter System C Insulation Check D Armature Coil EI Continuity Check Clean and inspect commutator outer surface Mica insulation must be lower than commutator bars undercut to ensure proper operation of commutator 2 Use an ohmmeter set to Rx1 scale Touch probes between 2 different segments of commutator and check for continuity Test all segments Continuity must exist between all or armature is bad 3 Check for continuity between armature coil segments and commutator segments There should be no continuity If continuity exists between any 2 armature is bad 4 Check armature windings insulation for shorting Shift Fork Check that shift fork is complete and pivot and contact areas are not excessively worn cracked or broken Brush Replacement 4 brushes and springs are serviced as a set Use a new Kohler brush and spring kit if replacement is necessary 1 Perform steps 1 5 in Starter Disassembly 2 Remove screws securing brush holder assembly to end ca
68. connector 3 Using an ohmmeter set on Rx1 scale check resistance between terminal 87 and pin 30 for coil 1 Repeat test between terminal 87 and pin 31 for coil 2 A reading of 1 8 4 0 Q in each test indicates that 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 specified range test coils separately from main harness as follows 1 Disconnect red and black primary leads from coil terminals 2 Connect an ohmmeter set on Rx1 scale to primary terminals Primary resistance should be 1 8 2 5 Q 3 Disconnect secondary lead from spark plug Connect an ohmmeter set on Rx10K scale between spark plug boot terminal and red primary terminal Secondary resistance should be 13 000 17 500 O 4 If secondary resistance is not within specified range unscrew spark plug lead nut from coil secondary tower and remove plug lead Repeat step b 3 testing from secondary tower terminal to red primary terminal If resistance is now correct coil is good but spark plug lead is faulty replace lead If step b 2 resistance was incorrect and or secondary resistance is still incorrect coil is faulty and needs to be replaced Spark Plugs EFI engines require resistor spark plugs Do not try to substitute non resistor plugs KohlerEngines com 29 EFI System Wiring Harness Wiring harness used in EFI system connect
69. cutout is offset down and facing away from flywheel side Install mounting screws and position clamp for stator leads on upper screw Torque screws to 15 3 N m 135 in Ib 2 Place stator leads within clamp and close loop 3 If violet B charge lead is separate from main harness secure it to wiring harness with a tie strap directly above clamp Install Starter Assembly NOTE Stator leads and rectifier regulator plug must be above starter 1 Mount starter to adapter plate using screws 2 Make sure starter is square to flywheel and torque screws to 15 3 N m 135 in Ib 3 Attach leads to appropriate starter solenoid terminals 4 To avoid damage or breakage do not over tighten nut when attaching positive battery cable Torque nut to 6 9 N m 53 79 in Ib Install Lower Flywheel Cover Rectifier Regulator and Mounting Plate 1 Install make sure small metal spacers are positioned in mounting holes of lower flywheel cover 2 Attach lower flywheel cover to cylinder 2 oil filter side lower radiator support bracket using M6 screws and flat washers Finger tighten only at this time 3 Align lower flywheel cover with cylinder 1 starter side lower radiator support bracket holes Position rectifier regulator mounting plate behind cover and install remaining two screws or nuts and flat washers Torque four fasteners to 9 9 N m 88 in Ib If screws and Timmerman nuts clips are used torque to 2 2 2 8 N m
70. d Black negative ohmmeter lead to 4 pin terminal Hold throttle closed and check resistance It should be 800 1200 O 66 690 07 Rev B Leave leads connected to pin terminals as described in step 3 Rotate throttle shaft slowly counterclockwise to full throttle position Monitor dial during rotation for indication of any momentary short or open circuits Note resistance at full throttle position It should be 1800 3000 Q Disconnect main wiring harness connector from TPS leaving TPS assembled to manifold Refer to chart below and perform resistance checks indicated between terminals in TPS switch with throttle in positions specified Closed 800 1200 Closed 1800 3000 Full 1800 3000 Full 800 1200 Any 1600 2500 If resistance values in steps 3 4 and 5 are within specifications go to step 6 If resistance values are not within specifications or a momentary short or open circuit was detected during rotation step 4 TPS needs to be replaced go to step 7 Check TPS circuits input ground between TPS plug and main harness connector for continuity damage etc Circuits 8 and 4 a Repair or replace as required b Turn idle speed screw back in to its original setting c Reconnect connector plugs start engine and retest system operation Remove two mounting screws from TPS Save screws for reuse Remove and discard faulty TPS Install replacement TPS and secure with original mounting screws a Reconn
71. d apply a light coating of engine oil to prevent rusting Measuring Piston to Bore Clearance Piston Detail 6 mm 0 2362 in NOTE Do not use a feeler gauge to measure piston to bore clearance it will yield inaccurate measurements Always use a micrometer Before installing piston into cylinder bore it is necessary that clearance be accurately checked This step is often overlooked and if clearances are not within specifications engine failure will usually result Use following procedure to accurately measure piston to bore clearance 1 Use a micrometer and measure diameter of piston above bottom of piston skirt and perpendicular to piston pin 2 Usean inside micrometer telescoping gauge or bore gauge and measure cylinder bore Take measurement approximately 63 5 mm 2 5 in below top of bore and perpendicular to piston pin 3 Piston to bore clearance is difference between bore diameter and piston diameter step 2 minus step 1 16 KohlerEngines com 66 690 07 Rev B Reassembly Crankcase Components eU o 2 Oil Seal Locking Tab Thrust Washer Gerotor Gears Camshaft D Style A Oil Filter Crankshaft P Connecting Rod Piston Style A T Closure Plate Style B Oil Pump Cover O ring X Outer Gerotor Gear Style B Style B D D Closure Plate Style A Governor Gear Shaft ep men e Oil Pump Assembly l DE wee Ile M Governor Cross Shaft N Piston P
72. d separate solenoid from starter for testing To test solenoid pull in coil plunger To test solenoid hold in coil Actuation Function 1 Use a 12 volt power supply and 2 test leads 1 Connect a 12 volt test lead to flat spade S start 2 Connect 1 lead to flat spade S start terminal on m on le si d lead to body or solenoid Momentarily connect other lead to lower mounting surface or SOIENOIG large post terminal 2 Manually push plunger IN and check if coil holds When connection is made solenoid should energize plunger retracted Do not allow test leads to remain audible click and plunger retract Repeat test connected to solenoid for a prolonged period of time several times Continuity Continuity 1 Use an ohmmeter set to audible or Rx2K scale and 1 Use an ohmmeter set to audible or Rx2K scale and connect 2 ohmmeter leads to 2 large post terminals connect 2 ohmmeter leads to 2 large post terminals 2 Perform preceding solenoid hold in coil function test and check for continuity Meter should indicate 2 Perform solenoid pull in coil plunger actuation test continuity Repeat test several times and check for continuity Ohmmeter should indicate continuity Repeat test several times Condition Conclusion Solenoid fails to activate No continuity is indicated Plunger fails to stay retracted 66 690 07 Rev B KohlerEngines com 55 Cooling System Liquid coolant can get extremely hot from operation ae Turning radiat
73. delivery of fuel at 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 EFI fuel system A quick test will verify if system is operating 1 Disconnect and ground spark plug leads 2 Complete all safety interlock requirements and crank engine for approximately 3 seconds 3 Remove spark plugs and check for fuel at tips a If there is fuel at tips of spark plugs fuel pump and injectors are operating b If there is no fuel at tips of spark plugs check following 1 Make sure 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 equipped is fully opened 4 Make sure battery is supplying proper voltage 5 Check that fuses are good and that all electrical and fuel line connections are good 6 Test fuel pump and relay operation Example of Diagnostic Display FAULT CODES ECU continuously monitors engine operation against preset performance limits If operation is outside limits ECU activates MIL and stores a diagnostic code in its fault memory If component or system returns to proper function ECU will eventually self clear fault code and turn off MIL If MIL stays illuminated it warns customer that dealer service is required Upon receipt dealer technician can access fault code s to help determine what portion of system is malfunctioning Codes are acc
74. ds feet hair and clothing away from all moving parts to prevent injury Never operate engine with covers shrouds or guards removed Carbon Monoxide can cause severe nausea fainting or death Avoid inhaling exhaust fumes Engine exhaust gases contain poisonous carbon monoxide Carbon monoxide is odorless colorless and can cause death if inhaled Accidental Starts can cause severe injury or death Disconnect and ground spark plug lead s before servicing Before working on engine or equipment disable engine as follows 1 Disconnect spark plug lead s 2 Disconnect negative battery cable from battery Hot Parts can cause severe burns Do not touch engine while operating or just after stopping Never operate engine with heat shields or guards removed Cleaning Solvents can Cause severe injury or death Use only in well ventilated areas away from ignition sources Carburetor cleaners and solvents are extremely flammable Follow cleaner manufacturer s warnings and instructions on its proper and safe use Never use gasoline as a cleaning agent Electrical Shock can Cause injury Do not touch wires while engine is running KohlerEngines com mw Damaging Crankshaft and Flywheel Can Cause Personal Injury Using improper procedures can lead to broken fragments Broken fragments could be thrown from engine Always observe and use precautions and procedures when installing
75. e do not use antifreeze mixture greater than 7096 ethylene glycol in cooling system Do not use antifreeze with stop leak additive s or mix add other additives to cooling system Use only ethylene glycol antifreeze Cooling system capacity is approximately 2 liters 2 18 qt 1 Check condition of cooling system hoses clamps and associated components Replace as required 2 Fill with 2 0 L 2 1 U S qt equal parts of ethylene glycol anti freeze and water only Distilled or deionized water is recommended especially in areas where water contains a high mineral content Propylene glycol based anti freeze is not recommended 3 Fill radiator with coolant mixture Allow coolant to drain into lower areas Fill overflow reservoir to a level between FULL and ADD marks Reinstall radiator and reservoir caps 4 Start and run engine for five minutes Stop engine and allow to cool 5 Recheck coolant level in reservoir Coolant level should be between FULL and ADD marks Add coolant to reservoir if required Inspection Cooling Fan Assembly Belt and Drive Pulleys Cooling fan assembly used to draw air through radiator is attached to a hub and pulley assembly with sealed ball bearings This assembly is belt driven off flywheel via a lower split pulley and requires very little service or maintenance DO NOT operate engine without fan and properly functioning cooling system or engine damage will occur 1 Inspect fan for an
76. e camshaft bearing surfaces of crankcase and camshaft with engine oil Apply a small amount of grease to lips of oil seal 3 Rotate crankshaft and position timing mark of crankshaft gear at 12 o clock position 4 Turn governor cross shaft clockwise until lower end of shaft contacts crankcase cylinder 1 side Make sure cross shaft remains in this position while installing camshaft 5 Slide camshaft into bearing surface of crankcase positioning timing mark of camshaft gear at 6 o clock position Make sure that camshaft gear and crankshaft gear mesh and timing marks are aligned 66 690 07 Rev B Checking Setting Camshaft End Play 1 Install shim removed during disassembly onto camshaft 2 Position end play tool on camshaft 3 Apply pressure on end play checking tool pushing camshaft toward crankshaft Use a feeler gauge to measure end play between shim and end play tool Camshaft end play should be 0 076 0 127 mm 0 003 0 005 in 4 f camshaft end play is not within specified range remove original shim and reinstall end play tool Use a feeler gauge to determine clearance between camshaft and tool Subtract 0 100 mm 0 004 in from measured clearance to obtain required shim thickness Refer to table below and install shim that matches calculated thickness Repeat steps 1 3 to verify that correct end play exists Camshaft Shims White 0 69215 0 73025 mm 0 02725 0 02875 in Blue 0 74295 0 78105 mm 0 02925 0
77. e from bushing and remove bushing from lever Mark hole position and unhook governor spring from governor lever Pivot throttle shaft and plate into Full Throttle position so tang of throttle shaft plate is against manifold casting Temporarily clamp in this position Rotate governor lever and shaft counterclockwise until it stops Use only enough pressure to hold it in that position Check how end of throttle linkage aligns with bushing hole in governor lever It should fall in center of hole If it doesn t perform adjustment procedure as follows Setting Initial Adjustment 1 Check split where clamping screw goes through governor lever There should be a gap of at least 1 32 If tips are touching and there is no gap present lever should be replaced If not already installed position governor lever on cross shaft but leave clamping screw loose TROUBLESHOOTING GUIDE Follow instructions in Step 2 of Checking Initial Adjustment then reattach throttle linkage to governor lever with bushing clip It is not necessary to reattach damper or governor springs at this time Insert a nail into hole in top of cross shaft Using light pressure rotate governor shaft counterclockwise as far as it will turn then torque hex nut on clamping screw to 6 8 N m 60 in Ib Make sure that governor arm has not twisted up or down after nut has been tightened Verify that governor has been set correctly With linkage still retained in Ful
78. e needs more fuel than one at or near operating temperature Mounted in oil filter adapter housing it has a temperature sensitive resistor that extends into oil flow Resistance changes with oil temperature altering voltage sent to ECU Using a table stored in its memory ECU correlates voltage drop to a specific temperature Using fuel delivery maps ECU then knows how much fuel is required for starting at that temperature Oxygen sensor functions like a small battery generating a voltage signal to ECU based upon difference in oxygen content between exhaust gas and ambient air 22 KohlerEngines com Tip of sensor protruding into exhaust gas is hollow Outer portion of tip is surrounded by exhaust gas with inner portion exposed to ambient air When oxygen concentration on one side of tip is different than that of other side a voltage signal between 0 2 and 1 0 volts is generated between electrodes and sent to ECU Voltage signal tells ECU if engine is straying from ideal 14 7 1 fuel mixture and ECU then adjusts injector pulse accordingly 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 Oxygen sensor grounds through metal shell so a good solid unbroken ground path back through exhaust system compon
79. e reading reappears at some point check for a problem rust corrosion loose joint or connection between that point and previous checkpoint For example if reading is too low at points on crankcase but correct voltage is indicated when black lead is touched to skin of muffler flange joints at exhaust ports become suspect 3 With sensor still hot minimum of 400 C 752 F switch meter to Rx1K or Rx2K scale and check resistance between sensor lead and sensor case It should be less than 2 0 KQ a If resistance is less than 2 0 KO go to Step 4 b If resistance is greater than 2 0 KO oxygen sensor is bad replace it 4 Allow sensor to cool less than 60 C 140 F and retest resistance with meter set on Rx1M scale With sensor cool resistance should be greater than 1 0 a If resistance is greater than 1 0 MO go to Step 5 b If resistance is less than 1 0 MO sensor is bad replace it o With oxygen sensor disconnected and engine not running disconnect main harness connector from ECU and set meter to Rx1 scale Check for continuity from pin 19 of ECU connector to shell of oxygen sensor and from pin 20 to sensor terminal of main harness Both tests should indicate continuity a If there is no continuity displayed in either of tests check harness circuit for breaks or damage and connections for poor contact moisture or corrosion If no continuity was found in first test also check for a poor broken ground
80. eck belt tension as described above When proper tension is obtained individually remove each capscrew of lower pulley apply Loctite 2429 to threads and reinstall Torque each capscrew in a criss cross sequence to 24 5 N m 215 in Ib Hoses and Tubes Hoses and tubes are used to connect components within cooling system To guard against coolant loss and hose failure hoses tubes and their connections should be checked regularly for leaks or damage Loss of coolant can result in serious engine damage Over time engine vibration can affect hose joint connections and hoses themselves can be affected by heat and coolant owelling hardening and or deterioration can occur depending on operating environment Deterioration usually takes place more rapidly from inside making outside inspections incomplete and not always dependable Regular outside inspection and careful inside inspection whenever connections are opened can minimize a possible in service problem Use new clamps whenever a hose is replaced or a joint connection is opened When making hose connections a light coating of rubber lubricant will make assembly easier Thermostat Testing and Servicing Temperature Sensor 58 KohlerEngines com Thermostat is mounted in intake manifold beneath thermostat housing It controls rapid warm up and operating temperature of engine If a problem is encountered which is thought to be fault of thermostat it can be checked t
81. ect both connector plugs b Perform appropriate TPS Initialization Procedure integrating new sensor to ECU TPS Initialization Procedure 1 Check that basic engine all sensors fuel fuel pressure and battery are good and functionally within specifications Important 2 66 690 07 Rev B Remove disconnect ALL external loads from engine belts pumps electric PTO clutch alternator rectifier regulator etc Locate service connector plug in wiring harness To initiate TPS auto learn function connect a jumper wire from TPS initialization pin 24 violet wire to battery voltage pin red wire or use jumper plug with blue jumper wire If using PC based diagnostic tool and software refer to Special Tests in Tools Aids and follow prompts to complete Start engine and immediately observe Malfunction Indicator Light MIL Light should start blinking 4 consecutive times every 2 seconds EFI System 5 Remove jumper wire or plug from service connector plug in wiring harness 6 Run engine at full throttle above 3000 RPM to warm up engine and initiate O sensor function in closed loop operation 7 Watch MIL When light starts blinking rapidly 5 blinks per second move throttle lever to low idle speed position Check and adjust idle speed to 1500 RPM using a tachometer Lamp should continue to blink rapidly for another 30 seconds before switching to a slow blink 8 When MIL blinks slowly do not do any
82. efore service ring sets are used 2 If cylinder bore does not need re boring and if old piston is within wear limits and free of score or scuff marks old piston may be reused 3 Remove old rings and clean up grooves Never reuse old rings 4 Before installing new rings on piston place top 2 rings each in turn in its running area in cylinder bore and check end gap Top and middle compression ring end gap clearance is 0 25 0 56 mm 0 0100 0 0224 in for a new bore or 0 94 mm 0 037 in for a used bore 5 After installing new compression top and middle rings on piston make sure top compression ring to groove side clearance is 0 025 0 048 mm 0 0010 0 0019 in and middle compression ring to groove side clearance 0 015 0 037 mm 0 0006 0 0015 in If side clearance is greater than specified a new piston must be used Piston Style B 1 Cylinder bore must be de glazed before service ring sets are used 2 If cylinder bore does not need re boring and if old piston is within wear limits and free of score or scuff marks old piston may be reused 3 Remove old rings and clean up grooves Never reuse old rings 66 690 07 Rev B Disassembly Inspection and Service 4 Before installing new rings on piston place top 2 rings each in turn in its running area in cylinder bore and check end gap Top compression ring end gap clearance is 0 189 0 277 mm 0 0074 0 0109 in for a new bore or 0 531 mm 0 0209 in for a u
83. egulator and mounting bracket Set mounting bracket into position b Secure regulator in base with original retaining ring or screws Be careful not to dent or damage body of regulator as operating performance can be affected 7 Reassemble and connect any parts removed in step 3 8 Reconnect negative battery cable 9 Recheck regulated system pressure at fuel rail test valve Fuel Rail Fuel rail is mounted to throttle body intake manifold No specific servicing is required unless operating conditions indicate that it needs internal cleaning or replacement It can be detached by removing mounting screws and injector retaining clips Thoroughly clean area around all joints and relieve any pressure before starting any disassembly Throttle Body Intake Manifold Assembly Throttle body intake manifold is serviced as an assembly with throttle shaft TPS throttle plates and idle speed adjusting screw installed Throttle shaft rotates on needle bearings non serviceable capped with rubber seals to prevent air leaks A throttle shaft repair kit is available to replace shaft if worn or damaged Appropriate TPS Initialization Procedure must be performed after any throttle shaft service 66 690 07 Rev B EFI System IDLE SPEED ADJUSTMENT RPM Idle Speed Screw Details Idle Speed Screw Adjustment Procedure 1 Make sure there are no fault codes present in ECU memory 2 Start engine and allow it to full
84. el injector s fuel filter fuel line or fuel pick up dirty restricted e Dirty air cleaner e Insufficient fuel pressure or fuel delivery e Vacuum intake air leak e Improper governor setting adjustment or operation e Speed sensor malfunction e TPS faulty mounting problem or TPS Initialization Procedure incorrect e Bad coil s spark plug s or wires e Base ignition timing incorrect Low Power 51 52 e Throttle plates in throttle body intake manifold not fully opening to WOT stop if so equipped Insufficient fuel delivery Dirty air filter Faulty malfunctioning ignition system TPS faulty or mounting problem Basic engine problem exists Improper governor adjustment e Plugged restricted exhaust e One injector not working e One spark plug coil or wire not working KohlerEngines com 45 Lubrication System This engine uses a full pressure lubrication system This system delivers oil under pressure to crankshaft camshaft and connecting rod bearing surfaces In addition to lubricating bearing surfaces lubrication system supplies oil to hydraulic valve lifters A high efficiency gerotor pump is located in closure plate Oil pump maintains high oil flow and oil pressure even at low speeds and high operating temperatures A pressure relief valve in closure plate limits maximum pressure of system Lubrication Components HERO A Neale ESR k E E CA OilSentry B Dipstick Oil
85. ent 1 Shut engine off and remove key Locate fuse holders Remove fuse cover and pull out fuse Inspect fuse for a solid fusible link or a broken fusible link Replace fuse if fusible link is broken If you are not sure if fusible link is broken replace fuse 5 Insert fuse into fuse holder until it is seated properly Install fuse cover gt e pe KohlerEngines com 51 Starter System ELECTRIC STARTING MOTOR NOTE Do not crank engine continuously for more than 10 seconds Allow a 60 second cool down period between starting attempts Failure to follow these guidelines can burn out starter motor NOTE If engine develops sufficient soeed to disengage starter but does not keep running a false start engine rotation must be allowed to come to a complete stop before attempting to restart engine If starter is engaged while flywheel is rotating starter pinion and flywheel ring gear may clash and damage starter NOTE If starter does not crank engine shut off starter immediately Do not make further attempts to start engine until condition is corrected NOTE Do not drop starter or strike starter frame Doing so can damage starter Engines in this series use solenoid shift starters Operation Solenoid Shift Starter When power is applied to starter electric solenoid moves drive pinion out onto drive shaft and into mesh with flywheel ring gear When pinion reaches end of drive shaft it rotates flywheel and cranks engine Whe
86. ents engine and wiring harness is required Any disruption or break in ground circuit can affect output signal and trigger misleading fault codes Keep that in mind when doing any troubleshooting associated with oxygen sensor 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 Electrical relay is used to supply power to injectors coil and fuel pump When key switch is turned ON and all safety switch requirements met relay provides 12 volts to fuel pump circuit injectors and ignition coils Fuel pump circuit is continuously grounded so pump is immediately activated and pressurizes system Activation of ignition coils and fuel injectors is controlled by ECU which grounds their respective ground circuits at proper times Fuel injectors mount into throttle body intake manifold and fuel rail attaches to them at top end Replaceable O rings on both ends of injector prevent external fuel leakage and also insulate it from heat and vibration A special clip connects each injector to fuel rail and holds itin place O rings must be replaced anytime injector is removed When key switch is on and relay is closed fuel rail is pressurized and voltage is present at injector At proper instant ECU completes ground circuit energizing injector Valve needle in injector is opened electromagnetically and pressure in fue
87. er Co engines to maintain EPA and CARB regulatory compliance OPERATION NOTE When performing voltage or continuity tests avoid putting excessive pressure on or against connector pins Flat pin probes are recommended for testing to avoid spreading or bending terminals EFI system is designed to provide peak engine performance with optimum fuel efficiency and lowest possible emissions Ignition and injection functions are electronically controlled monitored and continually corrected during operation to maintain ideal air fuel ratio Central component of system is Engine Control Unit ECU which manages system operation determining best combination of fuel mixture and ignition timing for current operating conditions An electric fuel pump is used to move fuel from tank through fuel line and in line fuel filter A fuel pressure regulator maintains a system operating pressure of 39 psi and returns any excess fuel to tank At engine fuel is fed through fuel rail and into injectors which inject it into intake ports ECU controls amount of fuel by varying length of time that injectors are ON This can range from 1 5 8 0 milliseconds depending on fuel requirements Controlled injection of fuel occurs each crankshaft revolution or twice for each 4 stroke cycle One half total amount of fuel needed for one firing of a cylinder is injected during each injection When intake valve opens fuel air mixture is drawn into combustion chamber
88. er tension is obtained individually remove each capscrew apply Loctite 2420 to 2 Set air cleaner mounting bracket assembly with threads of lower pulley and reinstall Torque four hose and elbow attached in position on engine bolts in a criss cross sequence to 24 3 N m Align all of mounting holes Start and finger tighten 215 in Ib each of mounting screws Make sure fuel line is tside of main bracket when installed 9 Mount RH and LH lower radiator supports with cross cue niinc dia Misi support bracket attached to crankcase using 3 Torque elbow mounting screws to 7 3 N m screws Snug screws only at this time 65 in Ib Then torque eight valve cover mounting screws to 6 2 N m 55 in Ib in sequence shown 4 Torque rectifier regulator ground wire screw to intake manifold to 7 3 N m 65 in Ib 5 Secure ECU adapter plate to mounting bracket Torque screws to 7 3 N m 65 in Ib Reconnect connector to ECU 88 KohlerEngines com 66 690 07 Rev B Reassembly 6 If removed install rain cap and secure with clamp 3 Carefully set radiator assembly into place guiding Check position of dust ejector it should face lower radiator hose inside RH support bracket Make downward Adjust end cap position as required sure that cooling fins do not come in contact with fan blades as radiator is installed 4 Position upper radiator support brackets on top of air 5 Connect wires for audible alarm if used Install Radiator
89. es to determine condition of part 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 is mounted on blower housing To replace disconnect plug s remove mounting screws and ground wire or metal grounding strap Testing rectifier regulator may be performed as follows using appropriate rectifier regulator tester To test 25 amp rectifier regulators 1 Connect tester ground lead with spring clamp to body of rectifier regulator 2 Connect red lead from tester to middle terminal labeled B 3 Connect black leads from tester to both outer AC terminals on rectifier regulator 4 Plug tester into proper AC outlet power supply for tester being used Turn on power switch POWER light should be illuminated and one of four status lights may be lit as well This does not represent condition of part 5 Press TEST button until a click is heard and then release Momentarily one of four status lights will illuminate indicating partial condition of part Condition Conclusion 25 amp OK green light comes on and stays steady Disconnect tester black lead attached to 1 AC terminal and reconnect it to other AC terminal Repeat test If OK green light comes on again part is good and may be used NOTE Aflashing LOW light can also occur as a result of Rectifier regulator is faulty and should not be used an inadequ
90. essed through key switch and displayed as blinks or flashes of MIL Access codes as follows 1 Start with key switch off 2 Turn key switch on off on off on leaving it on in third sequence 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 first digit followed by a pause and another series of blinks from 1 to 6 for second digit a It s a good idea to write down codes as they appear as they may not be in numerical sequence b Code 61 will always be last code displayed indicating end of code transmission If code 61 appears immediately no other fault codes are present After problem has been corrected fault codes may be cleared as follows 1 Disconnect negative battery cable from battery terminal or remove main fuse for ECU for approximately 1 minute 2 Reconnect cable and tighten securely or reinstall main fuse Start engine and allow it to run for several minutes MIL should remain off if problem was corrected and fault codes should not reappear codes 31 32 33 and 34 may require 10 15 minutes of running to reappear 1 Diagnostic display initiated through ignition key sequencing 2 Bag e p EI re je je de l k 3 MF Goen i Light remains on at end of transmission 36 KohlerEngines com 66 690 07 Rev B Diagnostic Code Summary Blink OB
91. est Kit Kohler 25 761 06 S Rectifier Regulator Tester 240 V AC 50Hz Kohler 25 761 41 85 Digital Vacuum Pressure Tester Design Technology Inc For checking crankcase vacuum DTI 721 01 Individual component available Design Technology Inc Rubber Adapter Plug DTI 721 10 Electronic Fuel Injection EFI Diagnostic Software Kohler 25 761 23 S For Laptop or Desktop PC EFI Service Kit Kohler 24 761 01 S For troubleshooting and setting up an EFI engine Components of 24 761 01 S Design Technology Inc Fuel Pressure Tester DTI 019 Noid Light DTI 021 90 Adapter DTI 023 In line T Fitting DTI 035 Code Plug Red Wire DTI 027 Code Plug Blue Wire DTI 029 Shrader Valve Adapter Hose DTI 037 Flywheel Holding Tool CS SE Tools KLR 82407 For holding flywheel of CS series engines Flywheel Puller SE Tools KLR 82408 For properly removing flywheel from engine Flywheel Strap Wrench SE Tools KLR 82409 For holding flywheel during removal 12 KohlerEngines com 66 690 07 Rev B Tools and Aide TOOLS Description Source Part No Hydraulic Valve Lifter Tool Kohler 25 761 38 S For removing and installing hydraulic lifters Ignition System Tester Kohler 25 455 01 S For testing output on all systems including CD Inductive Tachometer Digital Design Technology Inc For checking operating speed RPM of an engine DTI 110 Offset Wrench K and M Series Kohler 52 455 04 S For removing and reinstalling cylinder barrel retaining nuts
92. eteriorated or damaged in any way Never reuse an old seal 66 690 07 Rev B KohlerEngines com 81 Reassembly Install Cylinder Heads Cylinder Head Torgue Seguence NOTE Match numbers embossed on cylinder heads and crankcase 1 Check to make sure there are no nicks or burrs on sealing surfaces of cylinder head or crankcase 2 Rotate crankshaft to position piston in cylinder 1 to top dead center TDC on compression stroke 3 Install a new cylinder head gasket 4 Install cylinder 1 head onto number 1 side mounting studs 5 Install a plain washer onto each stud and secure with a nut 6 Torque nuts in two steps first to 16 9 N m 150 in Ib and then to 33 9 N m 300 in Ib using torque sequence shown 7 Repeat installation procedure for cylinder 2 side head Install Push Rods and Rocker Arms NOTE Push rods must always be installed in same position as before disassembly 1 Note mark or tag identifying push rod as either intake or exhaust for cylinder 1 Lightly apply engine oil or grease to ends of push rods and install Make sure that each push rod ball seats in its respective hydraulic lifter socket 2 Apply grease to contacting surfaces of rocker arms and rocker arm pivots Install rocker arms and rocker arm pivots on cylinder head 3 Install new rocker arm screws with Dri Loc thread locking compound on threads Torque screws to 11 3 N m 100 in Ib When tightening use a steady moti
93. fore performing any welding on equipment Initial Starting Priming Procedure Important EFI fuel system must be purged of air primed prior to initial start up and or any time system has been disassembled or fuel tank run dry 1 Locate electronic control unit ECU for EFI system Check part number on end If Part No is 24 584 28 or higher ECU has a built in priming feature a Turn key switch to ON RUN position You will hear fuel pump cycle on and off When fuel pump stops cycling approximately one minute system is primed start engine 2 For plastic cased ECU s below 24 584 28 S system can be primed by manually cycling fuel pump KohlerEngines com 23 EFI System a Turn key switch to ON RUN position Fuel pump will run for about three seconds and stop Turn switch off and back on to restart fuel pump Repeat this procedure until fuel pump has cycled five times then start engine 3 System can also be primed similar to relieving pressure a Connect pressure gauge as described above for relieving fuel pressure Depress and hold release button and crank engine until air is purged and fuel is visible in discharge tube If fuel is not visible after 10 seconds stop cranking and allow starter to cool for 60 seconds Priming Without a Test Valve in Fuel Rail NOTE Number of cranking intervals necessary will depend on individual system design and or when system has been disassembled 1 Crank engine in 10 15
94. g Hole A LoLo 9 1 S LE ZZ SHW PR a 101 60 p UE 4 000 PT AZ ption ji 4 Inch Square Key 112 92 8 18UNF Thread DODO N z 4 446 5 JO 7 16 20 Thread Option om kt Bn hl 36 50 28 575 Option 5 155 58 c 1 437 1 125 6 125 o 3 38 00 nee Top View 89 00 4 00 Pilot Oil Drain Plug 3 504 157 Mounting Holes Mounting Surface Mounting Hole A 431 61 16 992 KohlerEngines com Specifications ENGINE IDENTIFICATION NUMBERS Kohler engine identification numbers model specification and serial should be referenced for efficient repair ordering correct parts and engine replacement Liquid Cooled Horizontal Shaft Numerical Designation Specification LH775 0001 Serial 4123500328 Year Manufactured Code D Factory Code Year 2011 42 2012 43 2013 GENERAL SPECIFICATIONS LH775 TORQUE SPECIFICATIONS LH775 Intake Manifold Intake Manifold Fastener torque in 2 increments first to 7 4 N m 66 in Ib finally to 9 9 N m 88 in Ib Thermostat Housing Mounting Fastener 6 2 7 3 N m 55 65 in Ib Air Cleaner Elbow Mounting Fastener 9 9 N m 88 in Ib Closure Plate Closure Plate Fastener 24 4 N m 216 in Ib Connecting Rod Cap Fastener torque in increments 11 3 N m 100 in Ib Crankcase Breather Cover Fastener 10 7 N m 95 in Ib into new hole 7 3 N m 65 in Ib into used hole Oil Drain Plug 13 6 N m 10 ft Ib
95. g with a wrench while torquing if possible to prevent applying unnecessary pressure on fitting and joint Check that formed tube and hose section have not been pulled up Install drive belt onto cogged pulley of water pump then around cam pulley Slide cam pulley with belt attached down onto keyway end of camshaft Be careful not to push key out of keyway and or into seal when installing pulley Check or use a feeler gauge to see that there is at least 3 17 mm 0 125 in clearance between underside of pulley and hose tube and clamps Remove pulley and reposition tube or clamps if required Install flat washer and screw to secure pulley in place Torque screw to 9 9 N m 88 in Ib KohlerEngines com 83 Reassembly Flywheel Ignition Intake Manifold Components H Adapter re Thermostat Housing C Thermostat D e Fuel Rail F Intake Manifold G Flywheel Fuel Injector ood m D Torgue Seguence Speed Sensor Speed Sensor Bracket 3 Setintake manifold with by pass hose and wiring Install Intake Manifold Assembly harness attached down into position onto gaskets 1 Check that gasket surfaces of intake manifold and and cylinder heads Install and finger tighten screws cylinder heads are clean and free of any nicks or in their appropriate locations Make sure clamps for damage wiring harness are positioned on long screw on each 2 Install new intake manifold aaskets onto port side Torque six intake manifold mounti
96. heel to be overstressed and damaged when screw is torqued to specifications NOTE Always use a flywheel strap wrench or holding tool to hold flywheel when tightening flywheel fastener Do not use any type of bar or wedge to hold flywheel as component damage and personal injury could result Make sure flywheel key is installed properly in keyway Flywheel can become cracked or damaged if key is improperly installed 1 Install woodruff key into keyway of crankshaft Make sure that key is properly seated and parallel with shaft 2 Thread starter mounting bolts into hub of flywheel or use flywheel puller to serve as a handle and set flywheel in place 3 Install screw and washer 4 Use a flywheel holding tool to hold flywheel and torque screw to 66 4 N m 49 ft Ib 5 Using a light visually check that sufficient clearance exists between cooling system components and bottom of flywheel e If clearance is OK continue with installation of ignition modules e If clearance is insufficient or contact is noted remove flywheel and adjust as required Reinstall flywheel and recheck for adequate clearance NOTE Install Speed Sensor 1 Secure speed sensor bracket with speed sensor to water pump with screws Torque to 10 7 N m 95 in Ib into new holes and 7 3 N m 65 in Ib into used holes 2 Check mounting and air gap of sensor It must be 1 5 mm 0 25 mm 0 059 0 010 in Install Spark Plugs 1 Check gap
97. hose section Position tube so its formed offset leads down and away from outlet perpendicular to pump Install clamp onto hose and position tangs of clamp parallel to those of first clamp Holding pump assembly elevated assemble transfer tube to 90 fitting in crankcase as follows a For new first time tube installation 1 Place a new ferrule compression ring in 90 fitting of crankcase and loosely install hex cap onto threads of fitting 2 Insert plain end of transfer tube through hex and compression ring b For reinstallation of an existing tube 1 Insert end of transfer tube with compression ring into 90 fitting of crankcase 2 Start hex cap onto threaded section of fitting Reassembly 90 fitting in crankcase is installed and sealed at factory in a specific position Special tools and procedures are involved Do not loosen remove or alter mounting position of this fitting at any time 8 10 11 Carefully push water pump down from raised position thereby rotating tube 90 within end connections Guide pump into position over O ring aligning two mounting pins and five screw hole locations Start screws with longer screw nearest pump outlet Torque screws to 9 9 N m 88 in Ib in sequence shown Push down on formed tube and hold in this position to prevent it from pivoting upward when tightening hex cap Torque hex cap to 22 6 N m 200 in Ib to secure joint connection Support fittin
98. hout noticeable bearing play wobble or binding 3 Check v belt for excessive wear cracking or damage If proper belt tension cannot be obtained or condition of belt is suspect replace it with Kohler Part No 66 203 02 S Do not use a substitute belt KohlerEngines com 66 690 07 Rev B Disassembly Inspection and Service Flywheel Ignition Intake Manifold Components AU HN Lv qi EN e d D 44 I G Ue E a p Et Le m DACH d d k P uL RIT Zu E Fuel Rail F Intake Manifold m Thermostat Housing Thermostat D E S Throttle Position Speed Sensor et nr SE K Sensi Inspection Omo Spee o LT Inspect flywheel for cracks and flywheel keyway for 1 Disconnect speed sensor connector damage Replace flywheel if cracked Replace flywheel is damaged Remove Flywheel Inspect ring gear for cracks or damage Kohler does NOTE Always use a flywheel puller to remove flywheel not provide ring gears as a serviceable part Replace from crankshaft Do not strike crankshaft or flywheel if ring gear is damaged flywheel as these parts could become cracked Check charging system magnets to be sure they are not or damaged loose or cracked 1 Use a flywheel strap wrench or holding tool to hold flywheel Remove screw and flat washer 2 Use a puller to remove flywheel from crankshaft 3 Remove woodruff key from crankshaft keyway 66 690 07 Rev B KohlerEngines com 65 Disassembly Inspection and Service Remove Stator Assembly
99. icate O ring with oil and make sure it remains in groove as pickup is being installed 3 Install rotor Install oil pump body to closure plate and secure with screws Torque screws as follows a Install fastener into screw location 1 and lightly tighten to position pump b Install fastener into screw location 2 and fully torque to recommended value c Torque fastener in screw location 1 to 10 7 N m 95 in Ib into new holes or 6 7 N m 60 in Ib into used holes 5 After torquing rotate gear and check for freedom of movement Make sure there is no binding If binding occurs loosen screws reposition pump retorque screws and recheck movement P KohlerEngines com 71 Disassembly Inspection and Service Oil Pump Assembly Style B Oil pump is mounted inside closure plate If service is required continue with Disassembly Inspection and Reassembly Disassembly 1 Remove screws 2 Lift oil pump assembly from closure plate Remove outer gerotor gear from closure plate 3 Ensure ball and spring remain installed in pressure relief hole of closure plate If ball and spring fall out of pressure relief hole see reassembly for correct installation 4 Remove oil pump cover O ring from groove in closure plate Inspection Inspect oil pump housing gear and rotors for nicks burrs wear or any visible damage Inspect oil pump cover O ring for cuts nicks or any visible damage If any parts are worn or d
100. icating properties of engine oil 66 690 07 Rev B Troubleshooting CRANKCASE VACUUM TEST Ac CP Carbon Monoxide can cause severe nausea fainting or death unn Avoid inhaling exhaust fumes Engine exhaust gases contain poisonous carbon Keep hands feet hair and clothing away from all monoxide Carbon monoxide is odorless colorless moving parts to prevent injury Never operate engine and can cause death if inhaled with covers shrouds or guards removed Rotating Parts can cause severe injury Stay away while engine is in operation A partial vacuum should be present in crankcase when engine is operating Pressure in 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 Complete instructions are provided in kits To test crankcase vacuum with manometer To test crankcase vacuum with vacuum pressure gauge 1 Insert rubber stopper into oil fill hole Be sure pinch 1 Remove dipstick or oil fill plug cap clamp is installed on hose and use tapered adapters 5 Install adapter into oil fill dipstick tube opening to connect hose between stopper and one upside down over end of a small diameter dipstick manometer tube Leave other tube open to tube or directly into engine if a tube is not used atmosphere Check that water level in manometer is
101. if it is damaged After removing damaged shaft press or lightly tap replacement shaft into closure plate to depth shown Reassembly 1 Install locking tab thrust washer on governor gear shaft with tab down 2 Position regulating pin within governor gear flyweight assembly and slide both onto governor shaft 66 690 07 Rev B Disassembly Inspection and Service Oil Pump Assembly Style A Oil Pump Style A Torque Sequence Oil pump is mounted inside of closure plate If service is required continue with Disassembly Inspection and Reassembly Disassembly 1 Remove screws 2 Remove oil pump assembly from closure plate 3 Remove oil pump rotor 4 Remove oil pickup by unhooking locking clip and pulling it free from oil pump body Relief valve is a one piece style staked to oil pump housing removal should not be attempted nor is internal servicing possible If a problem with relief valve is encountered oil pump should be replaced Inspection Inspect oil pump housing gear and rotors for nicks burrs wear or any visible damage If any parts are worn or damaged replace oil pump Inspect oil pressure relief valve piston It should be free of nicks or burrs Check spring for wear or distortion Free length of spring should be approximately 47 4 mm 1 8 in Replace spring if it is distorted or worn Reassembly 1 Install pressure relief valve piston and spring Install oil pickup to oil pump body Lubr
102. ignited and burned 66 690 07 Rev B EFI System ECU controls amount of fuel being injected and ignition timing by monitoring primary sensor signals for engine temperature speed RPM and throttle position load These primary signals are compared to preprogrammed maps in ECU computer chip and ECU adjusts fuel delivery to match mapped values After engine reaches operating temperature an exhaust gas oxygen sensor provides feedback to ECU based upon amount of unused oxygen in exhaust indicating whether fuel mixture being delivered is rich or lean Based upon this feedback ECU further adjusts fuel input to re establish ideal air fuel ratio This operating mode is referred to as closed loop operation EFI system operates closed loop when all three of following conditions are met e Oil temperature is greater than 35 C 95 F e Oxygen sensor has warmed sufficiently to provide a signal minimum 375 C 709 F e Engine operation is at a steady state not starting warming up accelerating etc During closed loop operation ECU has 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 ideal air fuel ratio This system requires a minimum engine oil temperature greater than 80 C 176 F to properly adapt These adaptive values are maintained as long as ECU is not reset During certain operating per
103. illed fuel could ignite if it comes in contact with hot parts or sparks from ignition Never use gasoline as a cleaning agent NOTE E15 E20 and E85 are NOT approved and should NOT be used effects of old stale or contaminated fuel are not warrantable Fuel must meet these requirements e Clean fresh unleaded gasoline e Octane rating of 87 R M 2 or higher e Research Octane Number RON 90 octane minimum e Gasoline up to 10 ethyl alcohol 90 unleaded is acceptable e Methyl Tertiary Butyl Ether MTBE and unleaded gasoline blend max 15 MTBE by volume are approved e Do not add oil to gasoline e Do not overfill fuel tank e Do not use gasoline older than 30 days KohlerEngines com STORAGE If engine will be out of service for 2 months or more follow procedure below 1 Add Kohler PRO Series fuel treatment or equivalent to fuel tank Run engine 2 3 minutes to get stabilized fuel into fuel system failures due to untreated fuel are not warrantable 2 Change oil while engine is still warm from operation Remove spark plug s and pour about 1 oz of engine oil into cylinder s Replace spark plug s and crank engine slowly to distribute oil 3 Disconnect negative battery cable 4 Store engine in a clean dry place 66 690 07 Rev B Engine Dimensions Fuel Pump E Starter Side Flywheel End Air Intake Optional Orientation 583 30 22 965 490 74 Engine M
104. in Retainer O PistonPin Qa Piston Style B R Piston Ring Set s u Ball Style B Spring Style B w Oil P A bl DE Sty eB y z Oil Pick Up Style B NOTE Make sure engine is assembled using all Make sure all traces of any cleaner are removed before specified torque values tightening sequences engine is assembled and placed into operation Even and clearances Failure to observe specifications small amounts of these cleaners can quickly break down could cause severe engine wear or damage lubricating properties of engine oil e Ine eo CR mu a ele amount Check closure plate crankcase cylinder heads and ao bi deer Se yA Gen E Geer d valve covers to be certain that all old sealing material Ge Ze reso s e OLO has been removed Use gasket remover lacquer thinner Bp SIRT RE or paint remover to remove any remaining traces Clean surfaces with isopropyl alcohol acetone lacquer thinner or electrical contact cleaner M 66 690 07 Rev B KohlerEngines com Reassembly Install Flywheel End Oil Seal and Camshaft Oil Seal 1 Check to make sure that there are no nicks or burrs in crankshaft and camshaft seal bores of crankcase 2 Apply alight coat of engine oil to outside diameter of flywheel end oil seal 3 Install oil seal into crankcase using a seal driver Make sure oil seal is installed straight and true in bore until tool bottoms against crankcase 4 Apply a light coat of engine oil to outside diameter of camsh
105. inal in relay connector 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 a Clean connection and check wiring if circuit was not completed 3 Set meter for DC voltage Touch red tester lead to 30 terminal in relay connector A reading of 12 volts should be indicated at all times 4 Connect red lead of meter to 85 terminal in relay connector Turn key switch to ON position Battery voltage should be present a No voltage present indicates a problem with key switch in wiring or at connector b If voltage is present wiring to connector is good Turn ignition switch OFF and proceed to Step 5 to test relay 5 Connect an ohmmeter Rx1 scale between 85 and 86 terminals in relay There should be continuity 6 Attach ohmmeter leads to 30 and 87 terminals in relay First there should be no continuity Using a 12 volt power supply connect positive lead to 85 terminal and touch negative lead to 86 terminal When 12 volts is applied relay should activate and continuity should exist between 30 and 87 terminals Repeat test several times If at any time relay fails to activate circuit replace relay Electrical relay is used to supply power to injectors coils and fuel pump When key switch is turned ON and all safety switch requirements met relay provides 12 volts to fuel p
106. ing or working on EFI system Dirt even in small quantities can cause significant problems Clean any joint or fitting with parts cleaning solvent before opening to prevent dirt from entering system Always depressurize fuel system through fuel connector on fuel pump module before disconnecting or servicing any fuel system components Never attempt to service any fuel system component while engine is running or ignition switch is ON Do not use compressed air if 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 Avoid direct water or spray contact with system components Do not disconnect or reconnect ECU wiring harness connector or any individual components with ignition SE This can send a damaging voltage spike through ECU Do not allow battery cables to touch opposing terminals When connecting battery cables attach positive cable to positive battery terminal first followed by negative cable to negative battery terminal Never start engine when cables are loose or poorly connected to battery terminals Never disconnect battery while engine is running Never use a quick battery charger to start engine Do not charge battery with key switch ON Always disconnect negative battery cable before charging battery and also unplug harness from ECU be
107. iods such as cold starts warm up acceleration etc an air fuel ratio richer than 14 7 1 is required and system operates in an open loop mode In open loop operation oxygen sensor output is not used and controlling adjustments are based on primary sensor signals and programmed maps only System operates open loop whenever three conditions for closed loop operation above are not being met ECU is a brain or central processing computer of entire EFI fuel ignition management system During operation sensors continuously gather data which is relayed through wiring harness to input circuits within ECU Signals to ECU include ignition on off crankshaft position and speed RPM throttle position oil temperature exhaust oxygen levels and battery voltage ECU compares input signals to programmed maps in its memory to determine appropriate fuel and spark requirements for immediate operating conditions ECU then sends output signals to set injector duration and ignition timing ECU compares input signals to programmed maps in its memory to determine appropriate fuel and spark requirements for immediate operating conditions ECU then sends output signals to set injector duration and ignition timing ECU continually performs a diagnostic check of itself each of sensors and system performance If a fault is detected ECU can turn on a Malfunction Indicator Light MIL if equipped on equipment control panel store fault code in its fa
108. ip of valve needle or external weeping around injector body Loss of system pressure from leakage can cause hot restart problems and longer cranking times To check for leakage it will be necessary to loosen or remove blower housing which may involve removing engine from unit Fuel Injector Details KI 22 23 HUE mom es H a Me P mm qe P TERME a iN Y met Cal fa i Injector Inspection Points A Filter Strainer In Electrical Fuel Supply Connection Solenoid Winding Valve Housing Multi Orifice Director Valve Needle Plate With Calibrated Opening NOTE Do not apply voltage to fuel injector s Excessive voltage will burn out injector s Do not ground injector s with ignition ON Injector s will open turn on if relay is energized Injector problems typically fall into three general categories electrical dirty clogged or leakage An electrical problem usually causes one or both of injectors to stop functioning Several methods may be used to Check for Leaks check if injectors are operating 1 With 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 3 Disconnect electrical connector from an injector and listen for a change in idle performance only running on one cylinder or a change in injector noise or vibration
109. is OK Rectifier more regulator is faulty replace Voltage is less than 28 Stator is faulty replace volts Test stator further using an ohmmeter steps 3 and 4 3 With engine stopped measure resistance across stator leads using an ohmmeter Condition Conclusion Resistance is 0 1 0 2 Stator is OK ohms Resistance is 0 ohms Stator is shorted replace Resistance is infinity Stator is open replace ohms 4 With engine stopped measure resistance from each stator lead to ground using an ohmmeter Condition Conclusion IR contu is infinity ohms Stator is OK not shorted no continuity to ground Stator leads are shorted to ground replace Resistance or continuity measured 66 690 07 Rev B To test charging system for battery continuously charging at high rate 1 With engine running at 3600 RPM measure voltage from B lead to ground using a DC voltmeter Condition Conclusion Voltage is 14 7 volts or Charging system is OK less Battery is unable to hold charge service or replace Voltage is more than 14 7 Faulty rectifier regulator volts replace FUSES This engine has three 3 blade type automotive fuses Replacement fuses must have same rating as blown fuse Use fuse chart below to determine correct fuse Wire Color Fuse Rating 2 Purple Wires 30 amp Fuse 1 Red Wire w Black Stripe 1 Red Wire w White Stripe 10 amp Fuse 2 Red Wires 10 amp Fuse Fuse Replacem
110. ith burnishing stones Continue with burnishing stones until within 0 013 mm 0 0005 in of desired size and then use finish stones 220 280 grit and polish to final size A crosshatch should be observed if honing is done correctly Crosshatch should intersect at approximately 23 33 off horizontal Too flat an angle could cause rings to skip and wear excessively too steep an angle will result in high oil consumption 4 After resizing check bore for roundness taper and size Use an inside micrometer telescoping gauge or bore gauge to take measurements Measurements should be taken at three locations in cylinder at top middle and bottom Two measurements should be taken perpendicular to each other at each three locations KohlerEngines com 9 Disassembly Inspection and Service Clean Cylinder Bore After Honing Proper cleaning of cylinder walls following boring and or honing is very critical to a successful overhaul Machining grit left in cylinder bore can destroy an engine in less than one hour of operation after a rebuild 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 machining oil while maintaining a good level of suds If suds break down during cleaning discard dirty water and start again with more hot water and detergent Following scrubbing rinse cylinder with very hot clear water dry it completely an
111. ithout noise and there is no evidence of scoring grooving etc on races or bearing surfaces bearing can be reused Fillet Must Blend Smoothly with Bearing Journal Surface 74 KohlerEngines com 66 690 07 Rev B Governor Cross Shaft Oil Seal Cross Shaft Oil Seal Details 2 0 mm 0 0787 in Governor Cross Shaft Seal Remove governor cross shaft oil seal from crankcase and replace it with a new one if seal is damaged and or leaks Install new seal to depth shown usinga seal installer Remove Flywheel End Oil Seals 1 Remove flywheel end crankshaft and camshaft oil seals from crankcase Crankcase These engines contain a cast iron cylinder liner that may be reconditioned as follows Inspection and Service NOTE If bore is beyond wear limit a new miniblock or short block will be required 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 main bearing if equipped for wear or damage Replace crankcase using a mini block or short block if required Check cylinder bore for scoring In severe cases unburned fuel can cause scuffing and scoring of cylinder wall It washes necessary lubricating oils off piston and cylinder wall As raw fuel seeps down cylinder wall piston rings make metal to metal contact with wall Scoring of cylinder wall can also be caused by localized hot spots resulting from a cooling system problem or
112. ive battery cable from battery before servicing External Engine Components d or uet i E Ad Ap A W w z derf we a E il F Ai A i Fu f i d d E I PU Jd s ST ei de EI 2 ji e Flywheel Cover ka a Al Dipstck B Electric Starter C AdapierPiate D Oi Drain Plug E E Radiator Drain Plug KohlerEngines com 66 690 07 Rev B Disassembly Inspection and Service Clean all parts thoroughly as 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 manufacturer s instructions and safety precautions carefully Make sure all traces of cleaner are removed before engine is reassembled and placed into operation Even small amounts of these cleaners can quickly break down lubricating properties of engine oil Drain Oil from Crankcase and Remove Oil Filter Disconnect Spark Plug Leads NOTE Pull on boot only to prevent damage to spark plug lead 1 Disconnect leads from spark plugs Shut Off Fuel Supply i LO a a ET a A OilFilter Nipple B OilFilter 1 Remove exhaust system muffler and attaching 1 Remove oil fill cap and dipstick and one or both hardware from engine drain plugs Allow sufficient time for oil to drain out 2 Remove and discard oil filter Re
113. ivot of drive lever with drive lubricant Position fork end into space between captured washer and rear of pinion Slide armature into drive end cap and at same time seat drive lever into housing Install rubber grommet into matching recess of drive end cap Molded recesses in grommet should be out matching and aligned with those in end cap Install frame with small notch forward onto armature and drive end cap Align notch with corresponding section in rubber grommet Install drain tube in rear cutout if it was removed previously Install flat thrust washer onto commutator end of armature shaft Starter reassembly when replacing brushes brush holder assembly a Hold starter assembly vertically on end housing and carefully position assembled brush holder assembly with supplied protective tube against end of commutator armature Mounting screw holes in metal clips must be up out Slide brush holder assembly down into place around commutator and install positive brush lead grommet in cutout of frame Protective tube may be saved and used for future servicing Starter reassembly when not replacing brushes brush holder assembly a Carefully unhook retaining caps from brush assemblies Do not lose springs b Position brushes back in their slots so they are flush with I D of brush holder assembly Insert brush installation tool with extension or use tube described above from a prior brush installation through
114. l Throttle position Step 2 unsnap bushing clip separate linkage from bushing and remove bushing from lever Follow Steps 3 and 4 in Checking Initial Adjustment Reconnect dampening spring into its governor lever hole from bottom Reinstall bushing and reattach throttle linkage Reattach governor spring in marked hole Start engine and allow it to fully warm up and establish closed loop operation approximately 5 10 min Check speed settings and adjust as necessary first low idle speed and then high speed setting Fails to Start When TPS offset incorrect Old stale fuel n Fails to Start When Insufficient fuel delivery TPS faulty KohlerEngines com 66 690 07 Rev B EFI System Fuel injector s fuel filter fuel line or fuel pick up dirty restricted Dirty air cleaner Insufficient fuel pressure or fuel delivery Engine Misses Hesitates or Stalls Under Load Vacuum intake air leak Speed sensor malfunction Improper governor setting adjustment or operation TPS faulty mounting problem or TPS Initialization Procedure incorrect Bad coil s spark plug s or wires Faulty malfunctioning ignition system Dirty air filter Insufficient fuel delivery Improper governor adjustment Low Power 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 W
115. l rail forces fuel down through inside Director plate at tip of injector contains a series of calibrated openings which directs fuel into manifold in a cone shaped spray pattern Injector is opened and closed once for each crankshaft revolution however only one half total amount of fuel needed for one firing is injected during each opening Amount of fuel injected is controlled by ECU and determined by length of time valve needle is held open also referred to as injection duration or pulse width It may vary in length from 1 5 8 milliseconds depending on speed and load requirements of engine 66 690 07 Rev B A high voltage solid state battery ignition system is used with EFI system ECU controls ignition output and timing through transistorized control of primary current delivered to coils Based on input from speed sensor ECU determines correct firing point for speed at which engine is running At proper instant it releases flow of primary current to coil Primary current induces high voltage in coil secondary which is then delivered to spark plug Each coil fires every revolution but every other spark is wasted An electric fuel pump is used to transfer fuel in EFI system Depending on application pump may be inside fuel tank or in fuel line near tank Pumps are rated for a minimum output of 25 liters per hour at 39 psi Pumps have an internal 60 micron filter In addition in tank style pumps will have a pre filter attached
116. le controls e Fuel pump malfunction vacuum hose clogged or leaking Intake system leak e Loose wires or connections that intermittently ground ignition kill circuit e Quality of fuel dirt water stale mixture e Restricted fuel tank cap vent Engine Starts Hard e Clogged fuel line or fuel filter e Engine overheated e Faulty ACR mechanism e Faulty or misadjusted choke or throttle controls e Faulty spark plug s e Flywheel key sheared e Fuel pump malfunction vacuum hose clogged or leaking Interlock switch is engaged or faulty e Loose wires or connections that intermittently ground ignition kill circuit e Low compression e Quality of fuel dirt water stale mixture e Weak spark 66 690 07 Rev B Engine Will Not Crank Battery is discharged Faulty electric starter or solenoid Faulty key switch or ignition switch Interlock switch is engaged or faulty Loose wires or connections that intermittently ground ignition kill circuit Pawls not engaging in drive cup Seized internal engine components Engine Runs But Misses Carburetor adjusted incorrectly Engine overheated Faulty spark plug s Ignition module s faulty or improperly gapped Incorrect crankshaft position sensor air gap Interlock switch is engaged or faulty Loose wires or connections that intermittently ground ignition kill circuit Quality of fuel dirt water stale mixture Spark plug lead s disconnected
117. linder temperatures get too high lacquer and varnish collect on pistons causing rings to stick which results in rapid wear A worn ring usually takes on a shiny or bright appearance 66 690 07 Rev B Scratches on rings and pistons are caused by abrasive material such as carbon dirt or pieces of hard metal Detonation damage occurs when a portion of fuel charge ignites spontaneously from heat and pressure shortly after ignition This creates two flame fronts which meet and explode to create extreme hammering pressures on a specific area of piston Detonation generally occurs from using low octane fuels Preignition or ignition of fuel charge before timed spark can cause damage similar to detonation Preignition damage is often more severe than detonation damage Preignition is caused by a hot spot in combustion chamber from sources such as glowing carbon deposits blocked cooling fins an improperly seated valve or wrong spark plug s 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 rings when installing pistons Never use old rings Some important points to remember when servicing piston rings Piston Style A 1 Cylinder bore must be de glazed b
118. ls in ECU connector using an ohmmeter Little or no resistance should be measured indicating that wiring of that particular circuit is OK An illustrated listing of numerical terminal locations is provided below On LH775 Kohler liquid cooled engines ECU and corresponding wiring harness provide two additional circuits Pin circuit 32 provides ability to control an optional OEM electric cooling fan switching it ON and OFF at appropriate coolant temperatures using a relay Pin circuit 12 switches on when coolant temperature is too high to operate an optional engine temperature warning light KohlerEngines com 33 EFI System CO O NO Ga R GN gt o 34 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 High Temperature Warning Output Not Used Injector 1 Output Injector 2 Output Not Used Diagnostic Line Throttle Position Temperature 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 Fan Control Output KohlerEngines com O AN O a AK WO N o O O O
119. ly Wet Fouled A wet plug is sed by excess fuel or oil in combustion chamber Excess fuel could be caused by a restricted air cleaner a carburetor problem or operating engine with too much choke Oil in combustion chamber is usually caused by a restricted air cleaner a breather problem worn piston rings or valve guides 66 690 07 Rev B Carbon Fouled K F Soft sooty black deposits indicate incomplete combustion caused by a restricted air cleaner over rich carburetion weak ignition or poor compression Overheated temperatures This condition is usually accompanied by excessive gap erosion Lean carburetor settings an intake air leak or incorrect spark timing are normal causes for high combustion temperatures Electrical System BATTERY A 12 volt battery with 400 cold cranking amps cca is generally recommended for starting in all conditions A smaller capacity battery is often sufficient if an application is started only in warmer temperatures Refer to following table for minimum capacities based on anticipated ambient temperatures Actual cold cranking reguirement depends on engine size application and starting temperatures Cranking reguirements increase as temperatures decrease and battery capacity shrinks Refer to equipment s operating instructions for specific battery requirements Battery Size Recommendations Above 32 F 0 C OFF to 32 F 18 C to C SPF to F 21 C to A8 C
120. ly there should be no continuity Using a 12 volt power supply connect positive lead to 85 terminal and touch negative lead to 86 terminal When 12 volts is applied relay should activate and continuity should exist circuit made between 30 and 87 terminals Repeat test several times If at any time relay fails to activate circuit replace relay 66 690 07 Rev B KohlerEngines com 27 EFI System FUEL INJECTOR 2 Make sure all safety switch requirements are met Crank engine and check for flashing of test light Repeat test at other connector a If flashing occurs use an ohmmeter Rx1 scale and check resistance of each injector across two terminals Proper resistance is 12 20 Q If injector resistance is correct check whether connector and injector terminals are making a good connection If resistance is not correct replace injector following steps 1 8 and 13 16 below b If no flashing occurs reattach connectors to both injectors Disconnect main harness connector from ECU and connector from relay Set ohmmeter to Rx1 scale and check injector circuit resistance between relay terminal 87 and pin 14 in main connector Then check resistance between relay terminal 87 and pin 15 Resistance should be 4 15 O 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 t
121. move Muffler Remove Starter and Adapter Plate 1 Disconnect leads attached to starter solenoid terminals 2 Remove screws securing starter to adapter plate 3 Remove screws attaching adapter to crankcase Note orientation of cutout Upper screw may also secure a clamp for stator leads Drain Coolant from Cooling System Coolant Drain Plug Details LA LEO EO A L Vtt et LE gx M D en 1 Loosen radiator cap then loosen radiator drain plug and allow system to drain Use a suitable container to catch coolant 2 If equipped remove coolant drain plugs on each side of block Allow any remaining coolant to drain out Dispose of coolant properly according to local regulations 66 690 07 Rev B KohlerEngines com 61 Disassembly Inspection and Service External Engine Components Radiator Assembly B Air Cleaner Assembly Ignition Module D Mounting Bracket E Adapter Pate F Remove ECU and Ignition Modules 1 Disconnect wire harness from ECU and remove screws securing adapter plate 2 Disconnect wire lead from ignition modules and remove screws securing ignition modules Retain spacers for reassembly ECU Remove Flywheel Cover Radiator Assembly Mounting Brackets and Attached Components NOTE Do not allow cooling fins of radiator to contact fan blades 1 Remove screws or nuts and flat washers 2 on each side securing lower flywheel cover to LH and RH radiator support brackets
122. n by decreasing engine downtime Here is a list of tools and their source SEPARATE TOOL SUPPLIERS Kohler Tools SE Tools Design Technology Inc Contact your local Kohler source of 415 Howard St 768 Burr Oak Drive supply Lapeer MI 48446 Westmont IL 60559 Phone 810 664 2981 Phone 630 920 1300 Toll Free 800 664 2981 Fax 630 920 0011 Fax 810 664 8181 TOOLS Description Source Part No Alcohol Content Tester Kohler 25 455 11 S For testing alcohol content in reformulated oxygenated fuels Camshaft Endplay Plate SE Tools KLR 82405 For checking camshaft endplay Camshaft Seal Protector Aegis SE Tools KLR 82417 For protecting seal during camshaft installation Cylinder Leakdown Tester Kohler 25 761 05 S For checking combustion retention and if cylinder piston rings or valves are worn Individual component available Design Technology Inc Adapter 12 mm x 14 mm Required for leakdown test on XT 6 engines DTI 731 03 Dealer Tool Kit Domestic Kohler 25 761 39 S Complete kit of Kohler required tools Components of 25 761 39 S Ignition System Tester Kohler 25 455 01 S Cylinder Leakdown Tester Kohler 25 761 05 S Oil Pressure Test Kit Kohler 25 761 06 S Rectifier Regulator Tester 120 V AC 60Hz Kohler 25 761 20 S Dealer Tool Kit International Kohler 25 761 42 S Complete kit of Kohler required tools Components of 25 761 42 S Ignition System Tester Kohler 25 455 01 S Cylinder Leakdown Tester Kohler 25 761 05 S Oil Pressure T
123. n engine starts and start switch is released starter solenoid is deactivated drive lever moves back and drive pinion moves out of mesh with ring gear into retracted position Troubleshooting Starting Difficulties Condition Possible Cause Conclusion Starter does not energize Battery Check specific gravity of battery If low recharge or replace battery as necessary Wiring Clean corroded connections and tighten loose connections Replace wires in poor condition and with frayed or broken insulation Starter Switch By pass switch or solenoid with a jumper wire If starter cranks or Solenoid normally replace faulty components Remove and perform individual solenoid test procedure Starter energizes but turns Battery Check specific gravity of battery If low recharge or replace slowly battery as necessary Brushes Check for excessively dirty or worn brushes and commutator Clean using a coarse cloth not emery cloth Replace brushes if excessively or unevenly worn Transmission Make sure clutch or transmission is disengaged or placed or in neutral This is especially important on equipment with Engine hydrostatic drive Transmission must be exactly in neutral to prevent resistance which could keep engine from starting Check for seized engine components such as bearings connecting rod and piston 52 KohlerEngines com 66 690 07 Rev B Solenoid Shift Starter Components Sh B Washer C Armature D Drive St
124. n manifold assembly over an appropriate container and turn key switch ON to activate fuel pump and pressurize system Do not turn switch to START position 12 If either injector exhibits leakage of more than two to four drops per minute from tip or shows any sign of leakage around outer shell turn ignition switch off and replace injector as follows 13 Depressurize fuel system following procedure in fuel warning on page Remove fuel rail mounting screws 14 Clean any dirt accumulation from sealing mounting area of faulty injector s and disconnect electrical connector s 15 Pull retaining clip off top of injector s Disconnect fuel rail and remove injector s from manifold 16 Reverse appropriate procedures to install new injector s and reassemble 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 fuel rail and blower housing mounting screws to 3 9 N m 35 in Ib and 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 design of injectors high fuel pressure and detergent additives in 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 director
125. ned to prevent engine from starting in a low oil or no oil condition 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 Oil Sentry pressure switch is installed in closure plate pressure port On engines not equipped with Oil Sentry installation hole is sealed with a 1 8 27 N P T F pipe plug Installation 1 Apply pipe sealant with Teflon Loctite PST 5927 Thread Sealant or equivalent to threads of switch 2 Install switch into tapped hole in closure plate 3 Torque switch to 10 1 N m 90 in Ib 66 690 07 Rev B Lubrication System Testing Compressed air a pressure regulator pressure gauge and a continuity tester are required to test switch 1 Connect continuity tester across blade terminal and metal case of switch With O psi pressure applied to switch tester should indicate continuity switch closed 2 Gradually increase pressure to switch As pressure increases through range of 7 11 psi tester should indicate a change to no continuity switch open Switch should remain open as pressure is increased to 90 psi maximum 3 Gradually decrease pressure through range of 7 11 psi Tester should indicate a change to continuity switch closed down to 0 psi 4 Replace switch if it does not operate as specified KohlerEngines com 47 Electrical System SPARK PLUG
126. ng screws in surfaces o colder Reade j two steps first to 7 4 N m 66 in Ib finally to 9 9 N m 88 in Ib in sequence shown 4 Install and tighten pipe plug or temperature warning switch if removed previously from threaded port of intake manifold Use pipe sealant with Teflon Loctite PST 592 Thread Sealant or equivalent on threads Torque to 22 6 N m 200 in Ib 84 KohlerEngines com 66 690 07 Rev B 5 Connect wire leads to temperature warning switch audible alarm and or Oil Sentry switch as equipped If thermostat and thermostat housing were removed from intake manifold reassemble them at this time 6 Make sure sealing surfaces of housing and manifold are clean and free of nicks or damage 7 Install thermostat into recess in intake manifold so larger spring end is down Place a new thermostat housing gasket onto manifold surface aligning screw holes Make sure that one of notches in gasket is aligned with by pass slot in manifold and thermostat housing Do not use a substitute gasket 8 Position thermostat housing on gasket and intake manifold Notch in manifold gasket and thermostat housing must all be aligned Install and torque screws to 9 9 N m 88 in Ib 9 Apply rubber lubricant to inside end of upper radiator hose and install hose to thermostat housing if separated for servicing Secure with clamp Make sure tangs of clamp point toward cylinder 1 away from fan Install Coolant B
127. nt applied to top of pulley indicating keyway location will make installation easier 66 690 07 Rev B 66 690 07 Rev B NOTE When installation is complete tangs of two hose clamps should face outward away from flywheel and slightly down Remove seal protector and or protective tape if used from over keyway and make sure end of camshaft is clean and free of any nicks or damage Install and fully seat key squarely into keyway Be careful not to contact camshaft seal Test fit cam pulley onto shaft and key it must slide on without force or restriction Remove pulley lf water pump by pass hose fitting was removed previously apply pipe sealant with Teflon Loctite PST 592 Thread Sealant or equivalent on threads and tighten it into pump Orient fitting so outlet points in 11 o clock position Check sealing surfaces of water pump and crankcase They must be clean and free of any nicks or damage Apply a small amount of grease in several locations to hold new water pump O Ring in place Install a new O ring in groove of crankcase Do not use RTV sealant in place of O ring or attempt to reinstall a used O ring Apply rubber lubricant to inner surfaces of short hose section Assemble hose to outlet of water pump and secure with larger diameter clamp Orient clamp so tangs extend out in 3 to 4 o clock position Slide smaller diameter clamp onto extruded end of formed metal tube and insert this end of tube into
128. o determine its operating condition Before removing and testing thermostat make sure all other possible causes such as debris accumulation obstruction leaks belt or fan failure coolant level and damaged components are eliminated as possible causes To Test Remove thermostat from system Hang or suspend thermostat by its frame in a container of water so thermostat does not touch bottom of container Heat water and measure temperature an oven thermometer can be used Spring loaded valve of thermostat should begin to open at 79 4 C 175 F and can be completely open at 90 C 195 F If valve opens at a temperature more than 10 degrees below specified opening or fails to open at a temperature 10 to 15 degrees above specified opening thermostat should be replaced If valve in thermostat can be moved or pushed off its seat with a slight effort when thermostat is cold unit may be considered defective and should be replaced Thermostat should be replaced if operation is found to be questionable or faulty Installation 1 Thoroughly clean sealing surfaces of intake manifold and thermostat housing with an aerosol gasket remover Make sure sealing surfaces are clean and free of nicks or damage Make sure notch in intake manifold is clean 2 Install a new thermostat into intake manifold so larger spring end is down into well of intake manifold Position a new thermostat gasket on intake manifold 3 Install thermostat housing
129. oat is further indication that air cleaner was not functioning properly e Check if oil level is within operating range on dipstick If it is above sniff for gasoline odor e Check condition of oil Drain oil into a container it 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 over rich fuel settings weak ignition overextended oil change interval or wrong weight or type of oil was used CLEANING ENGINE Cleaning Solvents can cause severe injury or death Use only in well ventilated areas away from ignition sources Carburetor cleaners and solvents are extremely flammable Follow cleaner manufacturer s warnings and instructions on its proper and safe use Never use gasoline as a cleaning agent After inspecting external condition of engine clean engine thoroughly before disassembly Clean individual components as 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 manufacturer s instructions and safety precautions carefully Make sure all traces of cleaner are removed before engine is reassembled and placed into operation Even small amounts of these cleaners can quickly break down lubr
130. ocation and disconnect governor spring from governor lever 66 690 07 Rev B Disassembly Inspection and Service 3 Tilt main bracket and disconnect choke linkage from choke lever Remove main control bracket 4 Unhook choke linkage from actuator lever on intake manifold Remove External Governor Controls 1 Loosen nut of governor lever mounting screw Leave throttle linkage and spring connected to lever Lift governor lever off governor shaft and lay assembly on top of crankcase to be removed with intake manifold External Engine Components LI 7 e r ye Per wie vs e e A Fus a Breather Hose Gasket Oil Sentry Breather Cover UA KE ve o DECADE ep ell EN EN K M Spacer Shims NJ Adapter Pulley Pulley Half 66 690 07 Rev B KohlerEngines com 63 Disassembly Inspection and Service Remove Oil Sentry If So Equipped 1 Disconnect wire lead from Oil Sentry switch and remove switch from breather cover Remove Breather Cover 1 2 Remove screws securing breather cover to crankcase Carefully pry under protruding edge of breather cover to separate and remove cover from gasket Do not pry on sealing surfaces as it could cause damage resulting in leaks Remove breather gasket and fiber filter from breather chamber Remove screw breather reed retainer and breather reed from breather chamber Remove Lower Drive Pulley and Fan Belt 1 2 Remo
131. on and or one silver ground screw is used crankcase normally No 4 or 6 position note these special Inspection assembly details for proper reassembly later nspect oil seal in closure plate and remove it if it is worn Locate three splitting tabs which are cast into or damaged perimeter of closure plate Insert drive end of a 1 2 breaker bar between top splitting tab and crankcase N Inspect main bearing surface for wear or damage Replace closure plate assembly if required 70 KohlerEngines com 66 690 07 Rev B Governor Gear Assembly Governor Shaft Press Depth Details Gear Shaft 19 40 mm 0 7638 in 34 0 mm 1 3386 in 33 5 mm 1 3189 in Governor gear assembly is located inside closure plate If service is required refer to these procedures Inspection Inspect governor gear teeth Replace gear if it is worn chipped or if any teeth are missing Inspect governor weights They should move freely in governor gear Disassembly NOTE Governor gear is held onto shaft by small molded tabs in gear When gear is removed from shaft these tabs are destroyed and gear must be replaced Therefore remove gear only if absolutely necessary Governor gear must be replaced once it is removed from closure plate 1 Remove regulating pin and governor gear assembly 2 Remove locking tab thrust washer located under governor gear assembly 3 Carefully inspect governor gear shaft and replace it only
132. on without interruption until proper torque is achieved Frictional heat from engaging threads may otherwise cause locking compound to set prematurely If new screws are not available apply Loctite 242 to bottom 4 or 5 threads Then install and torque screws to 11 3 N m 100 in Ib 4 Usea spanner wrench or rocker arm lifting tool see Tools and Aids to lift rocker arms and position push rods underneath 5 Rotate crankshaft so piston in cylinder 2 is at top dead center on compression stroke and repeat steps for remaining cylinder Do not interchange parts from one cylinder head with parts from other cylinder head 82 KohlerEngines com 6 Rotate crankshaft to check for free operation of valve train Check clearance between valve spring coils at full lift Minimum allowable clearance is 0 25 mm 0 010 in Install Valve Covers 1 Make sure sealing surfaces of cylinder heads and valve covers are clean and free of all old gasket material 2 Install new valve cover gaskets onto valve covers 3 Install valve covers with gaskets in their original locations 4 Install lower mounting screws in each cover and finger tighten only Upper screws will be installed later Install Water Pump Drive Belt and Transfer Tube Assembly Water Pump Components Eder T 14 ni Water Pump Camshaft Pulley f O ring Water Pump Belt EI Transfer Tube Water Pump Torque Sequence NOTE A mark or dot of pai
133. ond allowable range e PS bad Engine Wiring Harness Related e 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 Throttle Body Related e Throttle shaft inside TPS worn broken or damaged e Throttle plate loose or misaligned e Throttle plate bent or damaged allowing extra airflow past or restricting movement ECU Related e Circuit providing voltage or ground to TPS damaged e TPS signal input circuit damaged 66 690 07 Rev B KohlerEngines com EFI System Injector 1 circuit open shorted to ground or shorted to battery Injector 1 is not functioning because circuit is open shorted to ground or shorted to battery Engine will run very poorly with only one cylinder functioning Injector Related e Injector coil shorted or opened Engine Wiring Harness Related e 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 e Open main fuse F1 Fuel Pump Relay Related 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 ECU Related e Circuit controlling injector 1 damaged e Circuit controlling fuel pump relay damaged
134. onto intake manifold Install and torque screws to 9 9 N m 88 in Ib 5 Reconnect radiator hose and secure with hose clamp if separated previously p High Temperature Sensor A high temperature sensor may be mounted in intake manifold and is used to activate a warning light audible alarm or kill engine depending on application if safe operating temperature is exceeded Sensor is a normally open switch which completes a circuit when coolant temperature reaches rated temperature limit of switch For these engines temperature sensor limit is 123 8 C 255 F If warning device activates or engine kills indicating an excessive operating temperature check following 1 Make sure fan belt is in good condition and properly tensioned 2 Make sure cooling fan is properly secured not broken damaged or missing blades 3 Make sure all air intake and cooling surfaces are clean and free of debris accumulation 4 After engine has sufficiently cooled check coolant level in system to make sure it is not low or improperly mixed 5 Check cooling system for leaks 66 690 07 Rev B 6 Check thermostat and pressure test radiator cap 7 Make sure water pump and drive belt are operational 8 Check and inspect wiring from sensor for shorting or damage If none of those are found to be cause do following 1 Drain coolant from system so level is lower than installed position of temperature sensor 2 Remove
135. op LEI Retaining Ring Hl DriveEndCap NI Pug Solenoid P FrameandField R Nt Commutator End Plate HI Bot Starter Disassembly NOTE Do notreuse old retainer NOTE Do not soak armature or use solvent when cleaning Wipe clean using a soft cloth or use compressed air 1 Remove hex nut and disconnect positive brush lead bracket from solenoid terminal 2 Remove screws securing solenoid to starter 3 Unhook plunger pin from drive lever Remove gasket from recess in housing 66 690 07 Rev B Starter System 4 Remove thru larger bolts 5 Remove commutator end plate assembly containing brush holder brushes springs and locking caps Remove thrust washer from inside commutator end 6 Remove frame from armature and drive end cap 7 Remove drive lever pivot bushing and backing plate if equipped from end cap 8 Take out drive lever and pull armature out of drive end cap 9 Remove thrust washer from armature shaft 10 Push stop collar down to expose retaining ring 11 Remove retainer from armature shaft Save stop collar 12 Remove drive pinion assembly from armature 13 Clean parts as required Inspection Drive Pinion Check and inspect following areas e Pinion teeth for abnormal wear or damage e Surface between pinion and clutch mechanism for nicks or irregularities which could cause seal damage e Check drive clutch by holding clut
136. or cap when engine is hot can allow steam Pi Hot liquid can cause severe burns and scalding liquid to blow out and burn you severely Shut off machine Only remove radiator cap when cool enough to touch with bare hands Slowly loosen cap to first stop to relieve pressure before removing completely Do not loosen radiator cap while engine is operating or warm to touch When it is necessary to open cooling system at radiator cap shut off engine and remove filler cap only when cool enough to touch with bare hands Slowly loosen cap to Maintenance j l first stop to relieve pressure before removing completely Maintaining correct coolant level cleaning any debris Thi ti ti d f liauid accumulation from radiator surfaces and insuring all cack sem Sete UI CIEN sor vasi o DI parts are in proper operating condition is critical to ensuring long life proper system performance and preventing overheating To ensure proper air circulation Cooling System Components make sure radiator cooling fan drive belt pulleys Cooling system consists of these following components cooling fins and external surfaces of engine are kept e Radiator with removable screen clean and in good condition at all times Check coolant e Hoses level and clean away any debris accumulation daily or e Coolant Pump and Belt before each use Simultaneously inspect hoses and all e Thermostat system connections for signs of leakage Make sure e Intake Manifold
137. ounting Surface 19 320 Center of Air Intake 440 00 17 323 23 0 906 Rain Cap Removal KOMLER AEGS O OHV EE 184 20 Mounting Hole Specifications Dimensions in millimeters Inch equivalents shown in Oil Filter Side Optional Oil Fill ss 7 M JM Os aw H err 3 Jed PS SC eer li LX A 8 JET SE Ek k fm U p ALSO m mm D 673 70 26 524 Overall 622 54 24 509 Overall without Rain Cap ug ME 4 Tay VI GC m d DM LE l C A RN dere E k Pw l d S wA Wa date 152 08 5 987 T Ol a i Ml 7 252 127 90 5 035 Mounting Hole Mounting Hole A 458 49 18 051 Overall K EC KE 8 s wv Zi s LES BE 2X 297 47 BOX 455 892 am Te Wie SZ BGS 2 gu NL O77 M 66 690 07 Rev B 238 61 9 394 119 78 4 716 X 15 70 Oil Filter Removal 0 61 120 96 EE A Bolt Circle 197 00 4 762 39 00 7 756 Coolant 1 535 ENSITON Ole Il 299 00 Oil Filter 4x 7 16 14 UNC 2B Inch 80 Pilo 235 19 7 000 si 9 259 E Mountin
138. p plate Note orientation for reassembly later Discard old brush holder assembly 3 Clean component parts as required New brushes and springs come preassembled in a brush holder with a protective sleeve that will also serve as an installation tool 4 Perform steps 10 13 in Starter Reassembly sequence If starter has been disassembled installation must be done after armature drive lever and frame are installed Starter Reassembly NOTE Always use a new retainer Do not reuse old retainers that have been removed NOTE Correctly installed center pivot section of drive lever will be flush or below machined surface of housing 1 Apply drive lubricant to armature shaft splines Install drive pinion onto armature shaft 2 Install and assemble stop collar retainer assembly a Install stop collar down onto armature shaft with counter bore recess up o4 KohlerEngines com 10 11 b Install a new retainer in larger rear groove of armature shaft Squeeze with a pliers to compress it in groove c Slide stop collar up and lock it into place so recess surrounds retainer in groove If necessary rotate pinion outward on armature splines against retainer to help seat collar around retainer Install offset thrust stop washer so smaller offset of washer faces retainer collar Apply a small amount of oil to bearing in drive end cap and install armature with drive pinion Lubricate fork end and center p
139. placed Recondition valve seat inserts following instructions provided with valve seat cutter being used Final cut should be made with an 89 cutter as specified for valve seat angle Cutting proper 45 valve face angle as specified and proper valve seat angle 44 5 half of full 89 angle will achieve desired 0 5 1 0 full cut interference angle where maximum pressure occurs on outside diameters of valve face and seat 66 690 07 Rev B Disassembly Inspection and Service 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 valve face with a fine grade of grinding compound then rotate valve on its seat with grinder Continue grinding until a smooth surface is obtained on seat and on valve face Thoroughly clean cylinder head in soap and hot water to remove all traces of grinding compound After drying cylinder head apply a light coating of SAE 10 oil to prevent rusting Intake Valve Stem Seal These engines use valve stem seals on intake valves Always use a new seal when valves are removed from cylinder head Seals should also be replaced if deteriorated or damaged in any way Never reuse an old seal Hydraulic Lifters Inspection Check base surface of hydraulic lifters for wear or damage If lifters need to be replaced apply a liberal coating of Kohler lubricant to base of each new lifter before it is installed
140. pply a 1 16 bead of sealant to sealing surface of closure plate 4 Make sure end of governor cross shaft is lying against bottom of cylinder 1 inside of crankcase 5 If alignment pins were removed previously install them in their respective locations in crankcase 80 KohlerEngines com 66 690 07 Rev B Reassembly Cylinder Head Components A B Head C Hydraulic Lifter D E VaveStemSea F Vave Spring Cap G Spring H Valve Spring Retainers Wa Valve Spring Keepers J RockerArms K Rocker Arm Pivot M Wawe Cover N FuelPump Install Hydraulic Lifters Assemble Cylinder Heads NOTE Hydraulic lifters should always be installed in Prior to installation lubricate all components with engine same position as before disassembly oil paying particular attention to lip of valve stem seal valve stems and valve guides Install following items in order listed below using a valve spring compressor e Valve stem seals e Intake and exhaust valves e Valve spring caps e Valve springs e Valve spring retainers e Valve spring keepers 1 Lubricate lifters and lifter bores in crankcase with engine oil 2 Install lifters into their respective lifter bores according to location and cylinder number marked during assembly Valve Stem Seals These engines use valve stem seals on intake and exhaust valves Always use a new Seal before valves are installed in cylinder head Also replace seals if they are d
141. r midway between FULL and ADD marks then install radiator and reservoir caps Reconnect Battery and Spark Plug Leads Connect leads to spark plugs Reconnect positive battery lead first and negative lead last when connecting battery Testing Engine It is recommended engine be appropriately secured and operated on a test stand or bench prior to installation in application 1 Make sure all hardware is tightened and hose clamps are properly secured 2 Setup engine on a test stand Install an oil pressure gauge Start engine and check to be certain that oil pressure 20 psi or more is present Run for 5 10 minutes between idle and mid range 3 Check all cooling system components and joint connections for leaks 4 Make sure maximum engine speed does not exceed 3 50 RPM no load Adjust throttle and high speed stop as necessary Refer to Fuel System o Place throttle control into idle or slow position and check low idle speed RPM Refer to Fuel System if adjustment is required Stop engine 7 Recheck oil and coolant levels Oil level should be at F mark on dipstick and coolant level in reservoir should be midway between ADD and FULL marks Add additional amounts as required 66 690 07 Rev B 66 690 07 Rev B KohlerEngines com 91 1P66 690 07 2013 by Kohler Co All rights reserved ni 92 KohlerEngines com 66 690 07 Rev B
142. radiator hoses If they swell excessively while testing system they may be weak and should be replaced Gauge Needle Drops Quickly A steady drop or loss of pressure indicates serious leakage is occurring within system which must be located and corrected before engine is returned to service If a pressure loss is noted 1 With pressure on system apply a soap water solution and check all joint connections hoses and cooling system components for external leakage Repair or replace as required 66 690 07 Rev B Cooling System Remove dipstick and check appearance of oil in crankcase Another method would be to remove an oil drain plug and drain a small amount of oil for inspection A milky or an opaque color similar to chocolate milk indicates presence of engine coolant in oil Check for a blown head gasket step 3 below or a possible crack or internal leakage from water jacket Remove spark plugs Apply 14 15 lbs of pressure and listen inspect for internal coolant leakage into cylinder combustion chambers This can denote a head gasket failure leak If required further test by performing a Cylinder Leakdown Test as described in Troubleshooting KohlerEngines com 59 Disassembly Inspection and Service Accidental Starts can cause severe injury or Before working on engine or equipment disable engine as death follows 1 Disconnect spark plug lead s 2 Disconnect Disconnect and ground spark plug lead s negat
143. rated into fuel rail is a pressure relief test valve for testing operating pressure or relieving fuel system pressure for servicing Fuel supply line is attached to barbed end of fuel rail with an Oetiker hose clamp EFI engines have no carburetor so throttle function regulate incoming combustion airflow is incorporated in intake manifold assembly Manifold consists of a one piece aluminum casting which also provides mounting for fuel injectors throttle position sensor fuel rail air baffle idle speed screw and air cleaner assembly Idle speed is only adjustment that may be performed on EFI system Standard idle speed setting for EFI engines is 1500 RPM but certain applications might require a different setting Check equipment manufacturer s recommendation 66 690 07 Rev B EFI System For starting and warm up ECU will adjust fuel and ignition timing based upon ambient temperature engine temperature and loads present In cold conditions idle speed will probably be higher than normal for a few moments Under other conditions idle speed may actually start lower than normal but gradually increase to established setting as operation continues Do not attempt to circumvent this warm up period or readjust idle speed during this time Engine must be completely warmed up in closed loop operating mode for accurate idle adjustment IMPORTANT NOTES e Cleanliness is essential and must be maintained at all times when servic
144. ressure of 39 psi 3 is observed relay fuel pump and regulator are working properly Turn key switch off and depress valve button on tester to relieve system pressure a If pressure is too high and regulator is outside tank just down line from pump check that return line from regulator to tank is not kinked or blocked If return line is good replace regulator see Regulator on page b If pressure is too low install in line T between pump and regulator and retest pressure at that point If it is too low there also replace fuel pump 3 If pump did not activate step 2 disconnect plug from fuel pump Connect a DC voltmeter across terminals in plug turn on 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 terminals on pump to check for continuity a If there was no continuity between pump terminals replace fuel pump b If voltage was below 7 test wiring harness and relay as covered in Electrical Relay section 30 KohlerEngines com 4 f voltage at plug was good and there was continuity across pump terminals reconnect plug to pump making sure you have a good connection Turn on key switch and listen for pump to activate a If pump starts repeat steps 1 and 2 to verify correct pressure b If pump still does not operate replace it Fuel Pressure Regulator Fuel Pressure Regulator Details Pressure
145. rew 6 2 N m 55 in Ib Valve Cover Rocker Arms Valve Cover Fastener 6 2 N m 55 in Ib Water Pump Mounting Screw 9 9 N m 88 in Ib Pulley Mounting Screw 9 9 N m 88 in Ib CLEARANCE SPECIFICATIONS LH775 Camshaft End Play with shim 0 076 0 127 mm 0 0030 0 0050 in Running Clearance 0 025 0 063 mm 0 0010 0 0025 in Bore D New 20 000 20 025 mm 0 7874 0 7884 in Max Wear Limit 20 038 mm 0 7889 in Camshaft Bearing Surface O D New 19 962 19 975 mm 0 7859 0 7864 in Max Wear Limit 19 959 mm 0 7858 in Values are in Metric units Values in parentheses are English equivalents Lubricate threads with engine oil prior to assembly 66 690 07 Rev B KohlerEngines com 7 Specifications CLEARANCE SPECIFICATIONS Connecting Rod Connecting Rod to Crankpin Running Clearance New Max Wear Limit LH775 0 043 0 068 mm 0 0016 0 0026 in 0 083 mm 0 0032 in Connecting Rod to Crankpin Side Clearance 0 26 0 63 mm 0 0102 0 0248 in Connecting Rod to Piston Pin Running Clearance 0 015 0 028 mm 0 0006 0 0011 in Crankcase Governor Cross Shaft Bore I D New Max Wear Limit 8 025 8 075 mm 0 3159 0 3179 in 8 088 mm 0 3184 in Crankshaft End Play free 0 070 0 590 mm 0 0028 0 0230 in Crankshaft Sleeve Bearing D crankcase New Max Wear Limit Crankshaft Bore in closure plate New Max Wear Limit Crankshaft Bore in closure plate to Crankshaft Running
146. s electrical components providing current and ground paths for system to operate All input and output signaling occurs through a special all weather connector that attaches and locks to ECU Condition of wiring connectors and terminal connections is essential to system function and performance Corrosion moisture and poor connections are more likely cause of operating problems and system errors than an actual component Battery Charging System EFI engines are equipped with either a 15 or 25 amp charging system to accommodate combined electrical demands of ignition system and specific application Charging system troubleshooting information is provided in Electrical System FUEL COMPONENTS Fuel Pump Fuel pumps are non serviceable and must be replaced if determined to be faulty If a fuel delivery problem is suspected make certain pump is being activated through relay all electrical connections are properly secured 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 fuel pump and relay may be conducted 1 Connect black hose of Pressure Tester part of EFI Service Kit to test valve in fuel rail Route clear hose into a portable gasoline container or equipment fuel tank 2 Turn on key switch to activate pump and check system pressure on gauge If system p
147. s time Use a dial indicator to check crankshaft end play End play should be 0 070 0 590 mm 0 0027 0 0232 in Shims are available in five color coded thicknesses listed below if adjustment is needed 66 690 07 Rev B Reassembly Crankshaft End Play Shims Remove closure plate If end play requires adjustment remove original shim and install appropriate size replacement BLUE 0 48 0 52 mm 0 050 mm Nominal 0 019 in BLACK 0 667 0 705 mm 0 686 mm Nominal 0 27 in GREEN 0 8366 0 9127 mm 0 8750 mm Nominal 0 34 in YELLOW 1 9652 1 1414 mm 1 1033 mm Nominal 0 043 in RED 1 2938 1 3700 mm 1 3319 mm Nominal 0 052 in Install Closure Plate Oil Seal Cylinder Head Torque Sequence ERE A Oil Seal er 8 0 mm 0 315 in M Closure Plate Check to make sure that there are no nicks or burrs in crankshaft bore of closure plate 2 Apply a light coat of engine oil to outside diameter of oil seal 3 Drive oil seal into closure plate using a seal driver Make sure oil seal is installed straight and true in bore to depth shown KohlerEngines com 79 Reassembly 6 Install closure plate on crankcase Carefully seat camshaft and crankshaft into their mating bearings Closure Plate Sealant Pattern 1 Rotate crankshaft to help engage oil pump and governor gear meshes 7 Install screws securing closure plate to crankcase If a thick flat washer was used on one of screws install it in number 10 loc
148. second intervals allowing a 60 second cool down period between cranking intervals until engine starts ELECTRICAL COMPONENTS A 32 pin MSE 1 1 plastic cased ECU is used on these engines Never attempt to disassemble ECU It is sealed to prevent damage to internal components Warranty is void if case is opened or tampered with in any way All operating and control functions within ECU are preset No internal servicing or readjustment may be performed If a problem is encountered and you determine ECU to be faulty contact your source of supply Do not replace ECU without factory authorization Relationship between ECU and throttle position sensor TPS is very critical to proper system operation If TPS or ECU is changed or mounting position of TPS is altered applicable TPS Initialization Procedure must be performed to restore synchronization ENGINE SPEED SENSOR Speed Sensor Circuit A Corresponds To 10 In Main Connector C Corresponds To 9 In Main Connector Engine speed sensor is a sealed non serviceable assembly If Fault Code diagnosis indicates a problem within this area check and test as follows 24 KohlerEngines com 1 Check mounting and air gap of sensor It must be 1 5 mm 0 25 mm 0 059 in 0 010 in 2 Inspect wiring and connections for damage or problems 3 Make sure engine has resistor type spark plugs Disconnect main harness connector from ECU 5 Connect an ohmmeter between
149. section Conclusion Engine Wiring Harness Related e Pin circuit wiring or connectors Pin 20 Low Fuel Pressure Oxygen Sensor Related e Sensor connector or wiring problem e Exhaust leak e Poor ground path to engine sensor is case grounded Poor system ground from ECU to engine causing rich running while indicating lean 66 690 07 Rev B EFI System Code 32 Oxygen Sensor No change in sensor output signal Condition Open loop operation only may cause a drop in system performance and fuel efficiency Conclusion Engine Wiring Harness Related e Pin circuit wiring or connectors Pin 20 Oxygen Sensor Related e Sensor connector or wiring problem e Sensor contaminated or damaged e Sensor below minimum operating temperature 375 C 709 F e Poor ground path from sensor to engine sensor grounds through shell see Oxygen Sensor section KohlerEngines com 39 EFI System Code 33 Oxygen Sensor Fuel System Fault System too rich Temporary fuel adaptation control is at upper limit Condition 40 Fuel Supply Related nothing lean only rich e Restricted return line causing excessive fuel pressure e Fuel inlet screen plugged in tank fuel pump only e Incorrect fuel pressure at fuel rail Oxygen Sensor Related e Sensor connector or wiring problem Sensor contaminated or damaged e Exhaust leak e Poor ground path e Pin circuit wiring or connectors Pin 20
150. sed bore Middle compression ring end cap is 1 519 1 797 mm 0 0598 0 0708 in for a new bore or 2 051 mm 0 0808 in for a used bore 5 After installing new compression top and middle rings on piston make sure top compression ring to roove side clearance and is 0 030 0 070 mm 0 0010 0 0026 in and middle compression ring to groove side clearance 0 030 0 070 mm 0 0010 0 0026 in If side clearance is greater than specified a new piston must be used Install New Piston Rings 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 Install bottom oil control ring first and top compression ring last To install new piston rings proceed as follows 1 Oil control ring bottom groove Install expander and then rails Make sure ends of expander are not overlapped 2 Middle compression ring center groove Install center ring using a piston ring installation tool Make sure identification mark is up or dye colored stripe if contained is to left of end gap 3 Top compression ring top groove Install top ring using a piston ring expender Make sure identification mark is up or dye colored stripe if contained left of end gap Connecting Rods Offset stepped cap connecting rods are used in all these engines Inspection and Service Check bearing area big end for excessive wear
151. sits that may collect in oil passages Use following procedure to remove and replace plug Remove Crankshaft Plug 1 Drill a 3 16 in hole through plug in crankshaft 2 Thread a 3 4 in or 1 in long self tapping screw with a flat washer into drilled hole Flat washer must be Self Tapping Screw ES RE large enough to seat against shoulder of plug bore c Pug D Crankshaft 3 Tighten self tapping screw until it draws plug out of crankshaft Install New Crankshaft Plug Use 1 single cylinder camshaft pin as a driver and tap plug into plug bore until it seats at bottom of bore Make sure plug is tapped in evenly to prevent leakage Remove Governor Cross Shaft NOTE Always use a new retaining ring when reassembling Do not reuse old retaining ring 1 Remove retaining ring and nylon washer from governor cross shaft 2 Remove cross shaft and small washer out through inside of crankcase F High Point from Fillet Intersections G dbMnmum H This Fillet Area Must Be Completely Smooth Inspect gear teeth of crankshaft If teeth are badly worn chipped or some are missing replacement of crankshaft will be necessary Inspect crankshaft bearing surfaces for scoring grooving etc Replaceable bearing is used in crankshaft bore of closure plate and or crankcase Do not replace bearing unless they show signs of damage or are out of running clearance 0 039 0 074 mm 0 0015 0 0029 in If crankshaft turns easily w
152. ssive corrosion or a worn stem end Replace valves found to be in bad condition Valve Guides If a valve guide is worn beyond specifications it will not guide 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 valve guide and using a split ball gauge measure inside diameter of guide Then using an outside micrometer measure diameter of valve stem at several points on stem where it moves in valve guide Use largest stem diameter to calculate clearance by subtracting stem diameter from guide diameter If intake clearance exceeds 0 038 0 076 mm 0 0015 0 0030 in or exhaust clearance exceeds 0 050 0 088 mm 0 0020 0 0035 in determine whether valve stem or guide is responsible for excessive clearance Maximum D wear on intake valve guide is 7 134 mm 0 2809 in while 7 159 mm 0 2819 in is maximum allowed on exhaust guide 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 guides are within limits but 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 cylinder head Inserts are not replaceable but can be reconditioned if not too badly pitted or distorted If cracked or badly warped cylinder head should be re
153. t in specified range reconnect oxygen sensor lead With lead connected probe or connect sensor connection with red VOA meter lead Attach black VOA meter lead to a good ground location Start and run engine at 3 4 throttle and note voltage reading being signaled by oxygen sensor Reading should cycle between 0 2 v and 1 0 v which indicates oxygen sensor is functioning normally and fuel delivery is within prescribed parameters If voltage readings show a steady decline rev engine and check indicated reading again If voltage momentarily increases and then again declines without cycling engine may be running lean due to incorrect TPS initialization Shut off engine perform TPS initialization and then repeat test If TPS initialization cannot be achieved perform step c c Replace oxygen sensor see next page Run engine long enough to bring new sensor up to temperature and repeat output test from step 1 Cycling voltage from 0 2 to 1 0 v should be indicated 2 Move black voltmeter lead to engine ground location and repeat output test Same voltage 0 2 v 1 0 v should be indicated a If same voltage reading exists go on to Step 3 Protective Tube 26 KohlerEngines com b If voltage output is no longer correct a bad ground path exists between sensor and engine ground Touch black lead at various points backtracking from engine ground back toward sensor watching for a voltage change at each location If correct voltag
154. thin system 66 690 07 Rev B EFI 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 START Yes No REFER TO DIAGNOSTIC AID 3 RUN ON Yes L OPERATE AT VARIOUS SPEED LOAD CONDITIONS ARE FAULT CODES PRESENT No END OF TEST Yes gt REFER TO DIAGNOSTIC AID 2 FAULT CODES CLEAR CODES 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 RE
155. thing but wait until MIL shuts off This indicates that this procedure has been completed successfully 9 Shut off engine If learn procedure was successfully completed external loads removed disconnected in Step 2 may be reconnected If procedure was unsuccessful see Steps a and b following a If during this procedure MIL goes back into blinking 4 consecutive blinks every 2 seconds engine and O sensor have cooled down and out of closed loop operation prohibiting learning from occurring Repeat Steps 6 9 b If during procedure with engine running MIL stays ON continuously for more than 15 seconds turn off ignition Then initiate fault code sequence by doing three consecutive key on key off cycles leaving key ON in last sequence each key on key off sequence must be less than 2 5 seconds long Fault detected must be corrected before auto learn function can be re initiated PC based diagnostic tool and software may be used to read out fault code and assist with troubleshooting and repair ENGINE COOLANT TEMPERATURE SENSOR Temperature sensor is a sealed non serviceable assembly A faulty sensor must be replaced If a blink code indicates a problem with temperature sensor it can be tested as follows 1 Remove oil temperature sensor from adapter housing and cap or block adapter hole 2 Wipe sensor clean and allow it to reach room temperature 20 C 68 F 3 Unplug main harness connector from ECU 4
156. threads in connecting rod 4 Use a flat washer with correct I D to slip on capscrew and approximately 1 in O D Assemble capscrew and washer to joint surface of rod 14 KohlerEngines com 66 690 07 Rev B TROUBLESHOOTING GUIDE Troubleshooting When troubles occur be sure to check 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 and vary by engine specification Use these to locate causing factors Engine Cranks But Will Not Start e Battery connected backwards e Blown fuse e Carburetor solenoid malfunction e Choke not closing e Clogged fuel line or fuel filter Diode in wiring harness failed in open circuit mode DSAI or DSAM malfunction Empty fuel tank Faulty electronic control unit Faulty ignition coil s Faulty spark plug s Fuel pump malfunction vacuum hose clogged or leaking Fuel shut off valve closed Ignition module s faulty or improperly gapped Insufficient voltage to electronic control unit Interlock switch is engaged or faulty Key switch or kill switch in OFF position Low oil level Quality of fuel dirt water stale mixture e SMART SPARK malfunction e Spark plug lead s disconnected Engine Starts But Does Not Keep Running e Faulty carburetor e Faulty cylinder head gasket e Faulty or misadjusted choke or thrott
157. ting rod end cap Remove end cap 2 Carefully remove connecting rod and piston assembly from cylinder bore 3 Repeat above procedure for other connecting rod and piston assembly NOTE 72 KohlerEngines com Inspection Piston and Rings Components and Details za Piston Ring B End Gap Top eh Middle EEN E Ring Ris Expander Oil Control Ring n 3 Piece Dye Colored Stripe Scuffing and scoring of pistons and cylinder walls occurs when internal engine temperatures approach welding point of piston Temperatures high enough to do this are created by friction which is usually attributed to improper lubrication and or overheating of engine Normally very little wear takes place in piston boss piston pin area If original piston and connecting rod can be reused after new rings are installed original pin can also be reused but new piston pin retainers are required Piston pin is included as part of piston assembly if pin boss in piston or pin are worn or damaged a new piston assembly is required Ring failure is usually indicated by excessive oil consumption and blue exhaust smoke When rings fail oil is allowed to enter combustion chamber where it is burned along with fuel High oil consumption can also occur when piston ring end gap is incorrect because ring cannot properly conform to cylinder wall under this condition Oil control is also lost when ring gaps are not staggered during installation When cy
158. to inlet In line pump systems may also have a filter between tank and pump on pickup low pressure side When key switch is turned ON and all safety switch requirements are met ECU through relay activates fuel pump which pressurizes system for start up If key switch is not promptly turned to start position engine fails to start or engine is stopped with key switch ON as in case of an accident ECU switches off pump preventing continued delivery of fuel In this situation MIL will go on but it will go back off after 4 cranking revolutions if system function is OK Once engine is running fuel pump remains on Fuel pressure regulator assembly maintains required operating system pressure of 39 psi 3 A rubber fiber diaphragm divides regulator into two separate sections fuel chamber and pressure regulating chamber Pressure regulating spring presses against valve holder part of diaphragm pressing valve against valve seat Combination of atmospheric pressure and regulating spring tension equals desired operating pressure Any time fuel pressure against bottom of diaphragm exceeds desired top pressure valve opens relieving excess pressure returning excess fuel back to tank Fuel rail is a formed tube assembly that feeds fuel to top of injectors Tops of injectors fit into formed cups in fuel rail When rail is fastened to manifold injectors are locked into place A small retaining clip provides a secondary lock Incorpo
159. ull coolant flow through radiator where itis cooled After getting cooled in radiator coolant is drawn into pump through lower radiator hose and circulation starts all over again A cooling fan driven off flywheel by a belt draws ambient air through radiator to maintain cooling process Coolant will provide protection from 37 C 34 F to 108 C 226 F For protection and use outside indicated temperature limits follow antifreeze manufacturer s instructions on container but do not exceed 70 Checking Coolant Level NOTE Do not operate engine without coolant in system Do not remove radiator cap when hot Engine coolant is hot and under pressure and can cause antifreeze severe burns To prevent engine overheating DO NOT use antifreeze with stop leak additive s or put and damage do not exceed more than 70 any other additives in cooling system antifreeze in cooling system Coolant level should be checked at overflow reservoir located behind radiator on fan shroud 1 Check coolant level within overflow reservoir Coolant level should be between FULL and ADD marks on reservoir Do not operate engine with coolant level below ADD mark 56 KohlerEngines com 66 690 07 Rev B Add coolant to overflow reservoir as required which is a 50 50 mixture of ethylene glycol and water distilled or deionized water is recommended Drain Cooling System Radiator Drain Plug Details L SE zo ll pe PE E spuma Radi
160. ult memory and go into a default operating mode Depending on significance or severity of fault normal operation may continue A technician can access stored fault code using a blink code diagnosis flashed out through MIL An optional computer software diagnostic program is also available see Tools and Aids KohlerEngines com 21 EFI System ECU reguires a minimum of 7 0 volts to operate Adaptive memory in ECU is operational whenever reguired voltage is present however adapted values are lost if power supply is disrupted for any reason ECU will relearn adapted values if engine is operated for 10 15 minutes at varying speeds and loads after oil temperature exceeds 55 C 130 F To prevent engine over speed and possible failure a rev limiting feature is programmed into ECU If maximum RPM limit 4500 is exceeded ECU suppresses injection signals cutting off fuel flow This process repeats itself in rapid succession limiting operation to preset maximum Engine speed sensor is essential to engine operation constantly monitoring rotational speed RPM of crankshaft A ferromagnetic 60 tooth ring gear with two consecutive teeth missing is mounted on flywheel Inductive speed sensor is mounted 1 5 0 25 mm 0 059 0 010 in away from ring gear During rotation an AC voltage pulse is created within sensor for each passing tooth ECU calculates engine speed from time interval between consecutive pulses Two tooth gap creates an
161. ump circuit injectors and ignition coils fuel pump circuit is continuously grounded so pump is immediately activated and pressurizes system Activation of ignition coils and injectors is controlled by ECU which grounds their respective circuits at proper times EFI System Service A malfunctioning relay can result in starting or operating difficulties relay and related wiring can be tested as follows 1 2 Disconnect relay connector plug from relay Connect black lead of a VOA meter to a chassis ground location Connect red lead to 86 terminal in relay connector Set meter to test resistance Rx1 Turn key switch from OFF to ON Meter should indicate continuity ground circuit is completed for 1 to 3 seconds Turn key switch back off a Clean connection and check wiring if circuit was not completed Set meter for DC voltage Touch red tester lead to 30 terminal in relay connector A reading of 12 volts should be indicated at all times Connect red lead of meter to 85 terminal in relay connector Turn key switch to ON position Battery voltage should be present a No voltage present indicates a problem in wiring or at connector b If voltage is present wiring to connector is good Turn ignition switch OFF and proceed to test 5 to test relay Connect an ohmmeter Rx1 scale between 85 and 86 terminals in relay There should be continuity Attach ohmmeter leads to 30 and 87 terminals in relay Initial
162. valent to threads Torque to 4 5 N m 40 in Ib If Oil Sentry switch is mounted to side of crankcase torque switch to 12 4 N m 110 in Ib 8 If vacuum fitting was removed from crankcase vacuum fuel pump apply pipe sealant with Teflon Loctite PST 592 Thread Sealant or equivalent to threads of fitting and install With crankcase upright fitting must point to 1 30 position Reinstall Coolant Drain Plugs 4 ees 2 GR i Coolant Drain Plug 1 Reinstall brass coolant drain plugs in sides of crankcase and also cylinder head plugs if removed during head servicing Apply pipe sealant with Teflon Loctite PST 592 Thread Sealant or equivalent to threads and reinstall plugs Torque plugs to 36 7 N m 325 in Ib 66 690 07 Rev B Reassembly Install External Governor Controls and Main Control Bracket Control Panel Details Control Panel B Choke Lever E Governor Spring 1 Install governor lever onto governor cross shaft If separated connect throttle link to governor lever with plastic bushing Hook dampening spring into small middle hole 2 Move governor lever TOWARDS intake manifold as far as it will go wide open throttle and hold in this position 3 Insert a nail into hole in cross shaft and rotate shaft COUNTERCLOCKWISE as far as it will turn Then torque nut to 6 8 N m 60 in Ib 4 Connect choke lever of main control bracket to choke linkage from intake
163. ve four screws attaching lower drive pulley assembly to pulley adapter and flywheel Remove pulley halves with spacer shims from adapter and take fan belt off upper pulley fan assembly Note number of shims between pulley halves and on front side of pulley especially if same belt will be reinstalled Remove Fan Assembly Mounting Bracket and Fan Shaft NOTE Further disassembly of fan hub and pulley 64 assembly is not necessary unless a problem exists see If disassembly is performed note assembly order and position of parts 1 Remove front nut and washer securing fan assembly to fan shaft Remove fan and pulley assembly from upper mounting bracket 2 Remove screws and take off mounting bracket with fan shaft attached 3 Fan shaft may be removed from mounting bracket by removing rear nut if individual servicing of either part is required Inspection and Service Cooling fan assembly consists of a fan attached to a v pulley and bearing carrier hub rotating on a dual ball bearing fan shaft arbor Assembly is mounted with a bracket to intake manifold and driven via a split pulley off flywheel Inspect components carefully for signs of wear or damage 1 Inspect fan to make sure blades are in good condition and free of any cracks nicks or damage Area around fan mounting holes must also be free of any cracks or damage 2 Fan and hub assembly when mounted to center arbor shaft must rotate smoothly wit
164. y cracks damaged missing fan blades and secure mounting 2 Bearings in hub of pulley should rotate smoothly without roughness binding or play wobble 3 V groove of each pulley upper and lower should not be bent nicked or damaged Pulley mounting areas and lower pulley shims should be free of any cracks or elongation 4 Drive belt is designed and constructed for this system Do not use a substitute belt Check overall condition and replace belt if cracked damaged or proper tension cannot be established by repositioning of lower pulley shims Use only Kohler Part No 66 203 02 S belt if replacement is necessary See a Kohler authorized dealer for any necessary service KohlerEngines com of Cooling System Checking Fan Belt and Tension Fan belt and belt tension should be checked daily or before each use Fan belt should not be cracked damaged or exhibit excessive wear Proper tension is 12 7 mm 3 8 1 2 in belt deflection per side under 10 Ibs applied tension If belt is cracked damaged or is worn that relocation of pulley shims cannot establish proper belt tension belt should be replaced Use only Kohler Part No 66 203 02 S belt DO NOT use a substitute belt For a new belt assemble lower pulley with all three shims between pulley halves For a used original belt being reinstalled assemble with two or one shim s between pulley halves and remaining shim s on outside front of outer pulley half Ch
165. y pass Hose If separated from intake manifold through individual component servicing 1 If connector fitting for by pass hose was removed from manifold reinstall it at this time Apply pipe sealant with Teflon Loctite PST 592 Thread Sealant or equivalent onto threads and tighten so fitting faces points toward 2 side long intake manifold screw 2 Attach coolant by pass hose to fittings in water pump and intake manifold Secure with clamps 3 Connect wire leads to temperature warning switch audible alarm and or Oil Sentry switch as equipped Install Stator Assembly 1 Place a small amount of pipe sealant with Teflon Loctite PST 592 Thread Sealant or equivalent into holes for stator mounting screws Position stator assembly onto mounting studs so leads are at bottom and directed out toward cylinder 1 side in 3 o clock position Align mounting holes and install screws Torque each screw to 6 2 N m 55 in Ib Install Flywheel AACAUION _ Damaging Crankshaft and Flywheel Can Cause Personal Injury Using improper procedures can lead to broken fragments Broken fragments could be thrown from engine Always observe and use precautions and procedures when installing flywheel 66 690 07 Rev B Reassembly NOTE Before installing flywheel make sure crankshaft taper and flywheel hub are clean dry and completely free of lubricants Presence of lubricants can cause flyw
166. y warm up and establish closed looped operation approximately 5 10 min 3 Place throttle control in IDLE SLOW position and check idle speed with a tachometer Turn idle speed screw in or out as required to obtain 1500 RPM or idle speed specified by equipment manufacturer 4 Idle speed adjustment can affect high idle speed setting Move throttle control to full throttle position and check high idle speed Adjust as necessary to 3750 RPM or speed specified by equipment manufacturer INITIAL GOVERNOR ADJUSTMENT Initial governor adjustment is especially critical on EFI engines because of accuracy and sensitivity of 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 governor setting following should be used to check and or adjust governor and throttle linkage If governor throttle components are all intact but you think there may be a problem with adjustment follow Checking Initial Adjustment to check setting If governor lever was loosened or removed go immediately to Setting Initial Adjustment to perform initial adjustment KohlerEngines com 31 Engine Starts Hard or Engine Starts Hard or EFI System Checking Initial Adjustment 1 Unsnap plastic linkage bushing attaching throttle linkage to governor lever Unhook damper spring from lever separate linkag

LH775 Service Manual

Contents

Download Pdf Manuals

Related Search

Related Contents