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Service Manual - Kohler Engines

1. T ei 40sues qVINL UA sauibua 10328uu0 2 euruue 9 webeig BUUIM 142 24 690 01 Rev K KohlerEngines com co eo EFI SYSTEM ECH JOSU8S JOSU8S Jojoauuo9 onsouBeiq IV emejeduje IIO HV Josueg dYNL cy uonisog eo JV Josueg ueB xQo EK JOSU8S uonisog yeusyuerg QV Z o uoniuf ov L o uoniuf av ZR 10joefu en vv LR 10 oefuj Jang Z Jojoeuuo Aad A Jojoeuuo xoelg X esnJj VOL M jieuondo JIN U9IIMS eJnssaJg IO n JO O N JI Hes L Jojosuuo9 euw S dung Ian Y apeg o esnJj VOC d Joyeinbay saynooy e Jojeis N yoelg IN Kai 7 SHUM M uel f Xuld I ejdung njg eq 9 T a d u 19 4b J MOJISA T Ec ei 69 eS V vie e E 2 v T oSv 99 v 9 I I 3550 6666 00 66 805060 2 amp en m op F o o we we oO o 00 o 0 DUTI O OjO OOOO ojosi 2 L S 6 lol 4OSUSS dYNL u3i sauibua YOWMS Ady jeuondo pue 10 D9UUOD euruuo G Weibeig Bula 142 39 KohlerEngines com 24 690 0
2. After the 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 Following chart lists fault codes what they correspond to and what visual indications will be Following chart is a list of individual codes with an explanation of what triggers them what symptoms might be expected and probable causes OBD2 35 Pin 24 Pin ease Blink P Code Ap MA 1 7 MSE 1 0 1 1 Gade plicable to Connection or Failure Description Metal Plastic PI si c Note 32 Pin MSE Cased Cased Cased 1 1 ECU Sys ECU ECU Sys ECU tem Only System tem System No RPM Signal Y Y Y 21 P0335 Loss of Synchronization Y Y Y 22 P0120 TPS Signal Implausible N N N 2 22 P0122 TPS Open or Short Circuit to Ground Y Y Y 22 P0123 TPS Short Circuit to Battery Y Y Y 23 P0601 Defective ECU Y Y Y 24 Engine Speed Sensor Y Y Y 9 31 P0174 System too Lean Y Y Y 6 24 690 01 Rev K KohlerEngines com 81 EFI SYSTEM BOSCH OBD2 35 Pi
3. A WARNING High Pressure Fluids can puncture skin and cause severe injury or death eP Do not work on fuel system without proper training or safety equipment Engine exhaust gases contain poisonous carbon monoxide Carbon monoxide is odorless colorless and can cause death if inhaled 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 Fluid puncture injuries are highly toxic and hazardous If an injury occurs seek immediate medical attention KohlerEngines com A 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 24 690 01 Rev K MAINTENANCE INSTRUCTIONS Maintenance E A WARNING Disconnect and ground spark plug lead s X before servicing Accidental Starts can cause severe injury or Before working on engine or equipment disable engine as Fo death follows 1 Disconnect spark plug lead s 2 Disconnect negative battery cable from battery
4. 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 MAINTENANCE SCHEDULE Every 25 Hours or Annually e Service replace low profile precleaner if equipped Air Cleaner Intake Every 100 Hours or Annually e Change oil Lubrication System Replace low profile air cleaner element Air Cleaner Intake Air Cleaner Intake e e Remove and clean shrouds and cooling areas e Check oil cooler fins clean as necessary if equipped Lubrication System Every 150 Hours e Check heavy duty filter minder e Inspect heavy duty air filter paper element and inlet screen area Air Cleaner Intake Air Cleaner Intake Every 200 Hours e Replace unique Electronic Fuel Injection EFI fuel filter Every 200 Hours e Change oil filter Every 300 Hours e Replace heavy duty air cleaner element and check inner element Lubrication System Air Cleaner Intake Every 500 Hours or Annually e Replace spark plugs and set gap Electrical System Every 600 Hours e Replace heavy duty air cleaner inner element Air Cleaner Intake Perform these procedures more frequently under severe dusty dirty conditions REPAIRS SERVICE PARTS Kohler genuine service parts can be purchased from Kohler aut
5. NOTE Do notclean 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 Refer to Maintenance for Repairs Service Parts Service Gap 0 76 mm 0 03 in Thread Size 14 mm Reach 19 1 mm 3 4 in Hex Size 15 9 mm 5 8 in 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 94 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 from 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 e On a worn plug center electrode will be rounded and gap will be greater than specified gap Replace a worn spark plug immediately Wet Fouled A wet plug is caused by excess fuel or oil in combustion chamber Excess fuel could be caused by a restricted air cleaner a carburetor problem or operati
6. KOHLER Command PRO ECH630 ECH749 CH735 CH26 CH745 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 2 Safety 3 Maintenance 5 Specifications 22 Tools and Aids 25 Troubleshooting 29 Air Cleaner Intake 30 Electronic Fuel Injection EFI System ECH 59 Electronic Fuel Injection EFI System Bosch 92 Lubrication System 94 Electrical System 99 Starter System 103 Disassembly Inspection and Service 122 Reassembly 24 690 01 Rev K KohlerEngines com Safety SAFETY PRECAUTIONS A WARNING A hazard that could result in death serious injury or substantial property damage A 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 A WARNING Explosive Fuel can cause fires and severe burns ZA GL 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 gasolin
7. Yellow or Brown O Ring Style Cover w Integral Metal Spacers 6 2 N m 55 in Ib CLEARANCE SPECIFICATIONS ECH630 ECH680 ECH730 ECH749 CH26 CH735 CH745 Camshaft End Play with shim 0 101 0 406 mm 0 0040 0 0160 in 0 076 0 127 mm 0 0030 0 0050 in Running Clearance 0 025 0 105 mm 0 001 0 004 in 0 025 0 063 mm 0 0010 0 0025 in Bore I D New Max Wear Limit 20 000 20 025 mm 0 7874 0 7884 in 20 038 mm 0 7889 in 20 000 20 025 mm 0 7874 0 7884 in 20 038 mm 0 7889 in Bearing Surface O D New Max Wear Limit 19 920 19 975 mm 0 7843 0 7864 in 19 914 mm 0 7840 in 19 962 19 975 mm 0 7859 0 7864 in 19 959 mm 0 7858 in Connecting Rod Connecting Rod to Crankpin Running Clearance 21 C 70 F New Max Wear Limit 0 043 0 073 mm 0 0017 0 0029 in 0 088 mm 0 0035 in 0 030 0 055 mm 0 0012 0 0022 in 0 070 mm 0 0028 in Connecting Rod to Crankpin Side Clearance 0 26 0 63 mm 0 0102 0 0248 in 0 26 0 63 mm 0 0102 0 0248 in 3Values are in Metric units Values in parentheses are English equivalents 5 Lubricate threads with engine oil prior to assembly 16 KohlerEngines com 24 690 01 Rev K CLEARANCE SPECIFICATIONS Connecting Rod continued ECH630 ECH680 ECH730 ECH749 CH26 Specifications CH735 CH745 Connecting Rod to Piston Pin Running Clearance 21 C 70 F P
8. 1 Not Used 2 Not Used 3 Malfunction Indicator Light MIL Ground 4 Not Used 5 Not Used 6 Not Used 7 Not Used 8 Not Used 9 Battery Ground 10 lgnition Coil 2 Ground 11 Not Used 12 Not Used 13 Not Used 14 Safety Switch Ground 15 Not Used 16 ECU 17 Fuel Pump Control 12V 18 Not Used 15 Ignition Switch Switched 12V 16 Power for TPS sensor MAP sensor or TMAP sensor 5V 17 Oxygen Sensor O2 input 18 Battery Power Permanent 12V ECU BLACK CONNECTOR SIDE 123456789 ooo el w w ojo u m w w lei w w 0 u u 10 11 12 13 14 15 16 17 18 GREY CONNECTOR SIDE 10 11 12 13 14 15 16 17 18 123456789 E E Oooo uw n u w E s w e w e v Pinout of ECU 34 KohlerEngines com 24 690 01 Rev K 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 ECU pins are coated at factory with a thin layer of electrical grease to prevent fretting and corrosion Do not attempt to remove grease from ECU pins Relationship between ECU and throttle position sensor TPS is very critical to proper sys
9. 44 2014 45 2015 Factory Code GENERAL SPECIFICATIONS ECH630 ECH680 ECH730 ECH749 CH26 CH735 CH745 Bore 80 mm 3 15 in 83 mm 3 27 in 83 mm 3 27 in Stroke 69 mm 2 72 in 67 mm 2 64 in Displacement 694 cc 42 4 cu in 747 cc 45 6 cu in 725 cc 44 cu in Oil Capacity refill 1 9 L 2 0 U S qt Maximum Angle of Operation full oil level 25 TORQUE SPECIFICATIONS ECH630 ECH680 ECH730 ECH749 CH26 CH735 CH745 Blower Housing Into cored aluminum hole or weld nut M6 Into extruded hole in sheet metal m 55 in Ib into new holes m 35 in Ib into used holes 10 7 N m 95 in Ib into new holes 7 3 N m 65 in Ib into used holes 2 8 N m 25 in Ib into new holes 6 2 N m 55 in Ib into new holes 2 3 N m 20 in Ib into used holes 4 0 N m 35 in Ib into used holes M6 2 8 N m 25 in Ib into new holes 10 7 N m 95 in Ib into new holes 2 3 N m 20 in Ib into used holes 7 3 N m 65 in Ib into used holes Closure Plate Fastener 25 6 N m 227 in Ib 24 4 N m 216 in Ib Connecting Rod Cap Fastener torque in increments 11 6 N m 103 in Ib 8 mm straight shank 22 7 N m 200 in Ib 8 mm step down 14 7 N m 130 in Ib 6 mm straight shank 11 3 N m 100 in Ib Values are in Metric units Values in parentheses are English equivalents Exceed
10. 83 006 83 031 mm 3 2680 3 2689 in 83 081 mm 3 2709 in 82 988 83 013 mm 3 2672 3 2682 in 83 051 mm 3 2697 in 0 12 mm 0 0047 in Max Taper 0 05 mm 0 0020 in 0 05 mm 0 0020 in Cylinder Head Max Out of Flatness 0 076 mm 0 003 in 0 076 mm 0 003 in Governor Governor Cross Shaft to Crankcase Running Clearance 6 mm Shaft 8 mm Shaft Cross Shaft O D New Max Wear Limit 6 mm Shaft New Max Wear Limit 8 mm Shaft New Max Wear Limit 0 025 0 126 mm 0 0009 0 0049 in 7 949 8 000 mm 0 3129 0 3149 in 7 936 mm 0 3124 in 0 013 0 075 mm 0 0005 0 0030 in 0 025 0 126 mm 0 0009 0 0049 in 5 975 6 012 mm 0 2352 0 2367 in 5 962 mm 0 2347 in 7 949 8 000 mm 0 3129 0 3149 in 7 936 mm 0 3124 in Governor Gear Shaft to Governor Gear Running Clearance 0 090 0 160 mm 0 0035 0 0063 in 0 015 0 140 mm 0 0006 0 0055 in Gear Shaft O D New 5 990 6 000 mm 0 2358 0 2362 in Max Wear Limit 5 977 mm 0 2353 in Ignition Spark Plug Gap 0 76 mm 0 030 in Crankshaft Position Sensor Air Gap only on earlier design sensor bracket 0 2 0 7 mm 0 008 0 027 in Crankshaft Position Sensor Max Air Gap only on later design sensor bracket Piston Piston Rings and Piston Pin 2 794 mm 0 110 in Piston Style A LITT J Piston to Piston Pin Running Clearance 0 006 0 017 mm 0 0002 0 000
11. Design Technology Inc DTI 019 DTI 021 DTI 023 DTI 035 DTI 027 DTI 029 DTI 037 Flywheel Puller For properly removing flywheel from engine SE Tools KLR 82408 22 KohlerEngines com 24 690 01 Rev K TOOLS Description Tools and Aids Source Part No Hydraulic Valve Lifter Tool For removing and installing hydraulic lifters Kohler 25 761 38 S Ignition System Tester For testing output on all systems including CD Kohler 25 455 01 S Inductive Tachometer Digital For checking operating speed RPM of an engine Design Technology Inc DTI 110 Offset Wrench K and M Series For removing and reinstalling cylinder barrel retaining nuts Kohler 52 455 04 S Cil Pressure Test Kit For testing verifying oil pressure on pressure lubricated engines Kohler 25 761 06 S Rectifier Regulator Tester 120 volt current Rectifier Regulator Tester 240 volt current For testing rectifier regulators Components of 25 761 20 S and 25 761 41 S CS PRO Regulator Test Harness Special Regulator Test Harness with Diode Spark Advance Module SAM Tester For testing SAM ASAM and DSAM on engines with SMART SPARK Starter Servicing Kit All Starters For removing and reinstalling drive retaining rings and brushes Individual component available Starter Brush Holding Tool Solenoid Shift Kohler 25 761 20 S Kohler 25 761 41 S Design Technology Inc DTI 031 DTI 033 Kohler 2
12. and gauged for wear or damage There are many commercially available cleaners that will guickly 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 guickly break down lubricating properties of engine oil Disconnect Spark Plug Leads NOTE Pull on boot only to prevent damage to spark plug lead Disconnect leads from spark plugs Drain Oil from Crankcase and Remove Oil Filter NOTE Some models are equipped with an oil drain valve 1 Remove oil fill cap dipstick and 1 oil drain plug 2 Allow ample time for oil to drain from crankcase and oil filter 3 Remove and discard oil filter Remove Oil Cooler 1 Use an 8 mm Allen wrench to remove oil filter threaded nipple 2 Separate filter adapter from closure plate leaving oil lines attached Remove screws mounting oil cooler to blower housing then remove cooler lines and filter adapter as an assembly Remove Muffler 1 Remove exhaust system and attaching hardware from engine On engines equipped with a port liner remove it now 2 Remove oxygen sensor and disconnect connector from wire harness 104 KohlerEngines com Remove Air Cleaner Assembly Heavy Duty Air Cleaner 1 Remove nuts securing air cleaner as
13. 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 equipped is fully opened 4 Make sure battery is supplying proper voltage 5 Check that fuses are good and that no electrical or fuel line connections are damaged or broken 6 Test fuel pump module operation as described earlier under Fuel Pump Diagnostic Fault Code Summary Fault Code Connection or Failure Description 0031 Oxygen Sensor Heater Circuit Low Voltage 0032 Oxygen Sensor Heater Circuit High Voltage 0107 Manifold Absolute Pressure MAP or TMAP Sensor Circuit Low Voltage or Open 0108 Manifold Absolute Pressure MAP or TMAP Sensor Circuit High Voltage 0112 Intake Air Temperature IAT or TMAP Sensor Circuit Low Voltage 0113 Intake Air Temperature IAT or TMAP Sensor Circuit High Voltage or Open 0117 Coolant Oil Temperature Sensor Circuit Low Voltage 0118 Coolant Oil Temperature Sensor Circuit High Voltage or Open 0122 Throttle Position Sensor Circuit Low Voltage or Open 0123 Throttle Position Sensor Circuit High Voltage 0131 Oxygen Sensor 1 Circuit Low Voltage or Open 0132 Oxygen Sensor 1 Circuit High Voltage 0171 Maximum Adaptation Limit Exceeded 0172 Minimum Adaptation Limit Exceeded 0174 Lean Fuel Condition at High Load Open Loop 0201 Injector 1 Circuit Malfunction 0202 Injector 2 Circuit Malfuncti
14. provides a secondary lock High pressure fuel line is serviced as a complete assembly to prevent tampering and safety hazards Components are not individually serviceable Vent hose assembly is intended to vent fuel vapor out of fuel pump module and direct fuel vapor into throttle body Most EFI engines are equipped with an engine mounted purge port on Z2 cylinder barrel baffle This capped purge port can be used by OEM to vent fuel tanks or used in conjunction with a carbon canister kit for Tier III evaporative emissions compliance Purge port connects to vent hose assembly and directs all fuel vapor into throttle body If purge port remains unused port must remain capped to prevent dirt from entering engine EFI engines have no carburetor so throttle function regulate incoming combustion airflow is achieved with a throttle valve in a separate throttle body attached to intake manifold Throttle body intake manifold provides mounting for fuel injectors throttle position sensor either a separate MAP sensor and an intake air temperature IAT sensor or a TMAP sensor high pressure fuel line 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 24 690 01 Rev K EFI SYSTEM ECH For starting and warm up ECU wil
15. 0 827 in Deep 165 1 mm 6 5 in B C 7 16 14 UNC 2B in 21 mm 0 827 in Deep 196 8 mm 7 75 in B C Center Line Mounting Hole A 177 8 mm 7 0 in Pilot Diameter Engine Mounting Surface Solenoid Shift Starter 283 58 mm 11 164 in Muffler Mounting 50 00 mm 1 969 in Exhaust Port 1 M8 X 1 25 4 Studs 45 24 690 01 Rev K KohlerEngines com 11 Specifications Engine Dimensions with Low Profile Air Cleaner Starter Side 50 0 mm 1 969 in Center Line Spark Plug 432 58 mm 17 031 in 89 0 mm 3 504 in Lift Strap 12 0 mm 0 472 in Exhaust Port 1 Engine Mounting Surface C B 32 0 mm 1 260 in Exhaust Port 2 67 50 mm 2 657 in Muffler Mounting Bosses Oil Drain Plug 3 8 in NPT Dipstick Center Line Mounting Hole A 12 28 mm 0 483 in KohlerEngines com 24 690 01 Rev K ENGINE IDENTIFICATION NUMBERS Specifications Kohler engine identification numbers model specification and serial should be referenced for efficient repair ordering correct parts and engine replacement Model oean 9 oe ase Res ECH630 EFI Command Engine Horizontal Shaft Numerical Designation Specification ECH630 3001 Serial sd enden 4323500328 Year Manufactured Code Code Year 43 2013
16. 006 17 012 mm 0 6695 0 6698 in Max Wear Limit 17 025 mm 0 6703 in Pin O D New 16 995 17 000 mm 0 6691 0 6693 in 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 Oil Control Ring to Groove Side Clearance 0 060 0 190 mm 0 0022 0 0073 in Top Compression Ring End Gap New Bore 0 100 0 279 mm 0 0039 0 0110 in 0 189 0 277 mm 0 0074 0 0109 in Used Bore Max 0 490 mm 0 0192 in 0 531 mm 0 0209 in Middle Compression Ring End Gap 1 400 1 679 mm New Bore 0 0551 0 0661 in 1 519 1 797 mm 0 0598 0 0708 in Used Bore Max 1 941 mm 2 051 mm 0 0808 in 0 0764 in Thrust Face O D New 79 966 mm 82 978 mm 3 2668 in 3 1483 in Max Wear Limit 79 821 mm 82 833 mm 3 2611 in 3 1426 in Piston Thrust Face to Cylinder Bore Running Clearance New 0 025 0 068 mm 0 0010 0 0027 in 0 019 0 062 mm 0 0007 0 0024 in 3Values are in Metric units Values in parentheses are English equivalents 7 Measure 6 mm 0 2362 in above bottom of piston skirt at right angles to piston pin 8 Measure 13 mm 0 5118 in above bottom of piston skirt at right angles to piston pin 24 690 01 Rev K KohlerEngines com 19 Specifications CLEARANCE SPECIFICATIONS Valves and Valve Lifters EC
17. 20 O 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 as follows 24 Pin MSE 1 0 Plastic Cased ECU Check resistance between relay terminal 87 and pin 16 in main connector Then check resistance between relay terminal 87 and pin 17 Resistance should be 4 15 Q for each circuit 32 Pin MSE 1 1 Plastic Cased ECU Check 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 tip 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 24 690 01 Rev K Injector Inspection Points A Check for Leaks 10 11 12 13
18. 4 TPS needs to be replaced go to step 7 6 Check TPS circuits input ground between TPS plug and main harness connector for continuity damage etc See chart on pages 35 Pin MA 1 7 Metal Cased ECU Pin Circuits 12 and 27 24 Pin MSE 1 0 Plastic Cased ECU Pin Circuits 8 and 4 32 Pin MSE 1 1 Plastic Cased ECU Pin Circuits 8 and 4 a Repair or replace as required b Turn idle speed screw back in to its original setting c Reconnect connector plugs start engine and retest system operation 7 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 Reconnect both connector plugs b Perform appropriate TPS Initialization Procedure integrating new sensor to ECU TPS Initialization Procedure For 35 Pin MA 1 7 Metal Cased ECU and 24 Pin MSE 1 0 Plastic Cased ECU only 1 Check that basic engine all sensors fuel fuel pressure and battery are good and functionally within specifications Important 2 Remove disconnect ALL external loads from engine belts pumps electric PTO clutch alternator rectifier regulator etc 3 Start engine and allow it to warm up for 5 10 minutes so oil temperature is above 55 C 130 F 4 Move throttle control to idle position and allow engine to stabilize for a minimum of one minute 5 Install a heavy rubber band around thro
19. 93 13 6 120 24 4 216 33 9 300 40 7 360 17 0 150 Tightening Torque N m ft Ib 10 M10 21 7 16 27 1 20 47 5 35 66 4 49 81 4 60 33 9 25 M12 36 6 27 47 5 35 82 7 61 116 6 86 139 7 103 61 0 45 M14 58 3 43 76 4 56 131 5 97 184 4 136 219 7 162 94 9 70 Torque Conversions N m in Ib x 0 113 in lb N m x 8 85 N m ft Ib x 1 356 ft Ib N m x 0 737 24 690 01 Rev K KohlerEngines com 21 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 satisfaction 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 For testing alcohol content 96 in reformulated oxygenated fuels Kohler 25 455 11 S Camshaft Endplay Plate For checking camshaft endplay SE Tools KLR 82405 Camshaft Seal Protector Aegis For protecting seal during camshaft installation SE Tools KLR 82417 Cylin
20. BDC 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 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 preprogrammed 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 If TPS is loosened or repositioned appropriate TPS Learn Procedure must be performed to re establish baseline relationship between ECU and TPS Engine oil temperature sensor is used by system to help determine fuel requirements for starting a cold engine needs more fuel than one at or near operating temperature Mounted in breather cover it has a temperature sensitive resistor
21. Cased ECU Circuits 35 35A 45 and 45A 24 Pin MSE 1 0 Plastic Cased ECU Circuits 16 17 45 and 45A 32 Pin MSE 1 1 Plastic Cased ECU Circuits 14 15 and 45 e Injector e ECU grounds e ECU Diagnostic Aid 9 FUEL SYSTEM fuel pressure Possible causes for low fuel system pressure e Low fuel e Fuel filter plugged e Fuel supply line plugged e Fuel pump Possible causes for high fuel system pressure e Pressure regulator e Fuel return line plugged or restricted Diagnostic Aid 10 BASIC ENGINE cranks but will not run Possible causes e Refer to basic engine troubleshooting charts within Troubleshooting Electronic Fuel Injection ECH EFI and Electrical Systems 24 690 01 Rev K EFI SYSTEM BOSCH 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 Yes REFER TO DIAGNOSTIC AID 2 FAULT CODES CLEAR CODES DOES ENGINE START Yes p No gt REFER TO DIAGNOSTIC AID 3 RUN ON OPERATE AT VARIOUS SPEED LOAD CONDITIONS ARE FAULT CODES PRESENT Yes p REFER TO DIAGNOSTIC AID 2 FAULT CODES No END OF TEST CRANK ENGINE DOES MIL GO OFF CLEAR CODES Yes KEY OFF AND KEY ON LISTEN FOR FUEL PUMP REFER TO DIAGNOSTIC AID 4 SPEED SENSOR DOES FUEL PUMP CYCLE ON TH
22. Check condition of rubber seal and replace if necessary 4 Install new paper element on base install precleaner over paper element reinstall element cover and secure with wing nut Reinstall air cleaner cover and secure with knob Heavy Duty 1 Unhook retaining clips and remove end cap s 2 Check and clean inlet screen if equipped 3 Pull air 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 BREATHER TUBE Ensure sure both ends of breather tube are properly connected AIR COOLING A WARNING zt Hot Parts can cause severe burns 4 46 Do not touch engine while operating or just after stopping Never operate engine with heat shields or guards removed Proper cooling is essential To prevent over heating clean screens cooling fins and other external surfaces of engine Avoid spraying water at wiring harness or any electrical components Refer to Maintenance Schedule KohlerEngines com 29 EFI SYSTEM ECH A WARNING Explosive Fuel can cause fires and severe D burns L 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 a
23. Connections Code 0337 Bad Stator Component Crankshaft Position Sensor Bad Battery Fault Crankshaft Position Sensor No Signal e Low output charging system Condition Air gap incorrect loose sensor open or e Poor magnet in flywheel shorted connection or faulty sensor e Bad or missing fuse Conclusion Crankshaft Position Sensor Related e Sensor connector or wiring Code 0563 e Sensor loose or air gap incorrect Component System Voltage Crankshaft Position Sensor Wheel Fault System Voltage High Related Condition Faulty voltage regulator or shorted e Damaged teeth connection Engine Wiring Harness Related Conclusion Faulty Rectifier Regulator e Pin circuit wiring or connectors ECU pin Black 4 or Black 13 Gd e ECU to harness connection problem Bad Battery If code is stored in fault history and starts Code 61 ed Clear code no other service Component End of Code Transmission Code 0351 Component Ignition Coil Fault Cylinder 1 Ignition Coil Malfunction Condition Broken wire in harness may not be visible shorted connection or faulty sensor Conclusion Engine Wiring Harness Related e Connection to ignition or fuse e Pin circuit wiring or connectors e ECU pin Black 1 e ECU to harness connection problem Ignition System Related e Incorrect spark plug s used e Poor connection to spark plug 56 KohlerEngines com 24 690 01 Rev K Troubleshooting Flow Chart Following flow chart provides an alternative met
24. Loose parts would allow a vacuum leak making TMAP sensor report misleading information to ECU a Tighten all hardware and perform an ECU Reset and a TPS Learn Procedure to see if MIL will display a fault with sensor again If MIL finds a fault with TMAP sensor replace it Oxygen Sensor O Components 24 690 01 Rev K EFI SYSTEM ECH Cutaway Oxygen Sensor Components 0 Planar Element A Protection Shield B and Heater Stainless Steel C Lower Insulator D Housing E Upper Insulator F nat d ian G High Temp Water Seal Temperature must be controlled very accurately and gas constituents measured to a high degree of accuracy for absolute sensor measurements This reguires laboratory eguipment to determine a good or bad sensor in field Furthermore as with most devices intermittent problems are difficult to diagnose Still with a good understanding of system and sensor it is possible to diagnose many sensor problems in field Using diagnostic software connected to ECU is a useful technique for observing sensor performance However user must understand that such software reads a signal generated by ECU If there is an ECU or wiring problem readings could be misinterpreted as a sensor problem Digital nature of signal to software means that it is not reading continuous output of sensor A voltmeter can also be used as an effective tool in diagnosing sensors It is advisable to us
25. Mounting R 43480 mm 6 307 in S 0 618 in Oil Filter T Crankshaft Center Removal 315 25 mm 29 58 mm U 12412 in Spark Plug V Fuel Filter wa a Sena X a165 in Spark Boot Removal P 9 Plug Boot Removal 60 0 mm 2 362 in Air 39 66 mm 1 562 in Y a Z Spark Plug Removal AA Fuel Pump 24 690 01 Rev K KohlerEngines com 9 Specifications Engine Dimensions with Low Profile Air Cleaner Oil Filter Side QJ A 30 0 mm 1 181 in 371 44 mm ES A 14 624 in Spark Td Center C Fuel Pump D Oil Fill E Dipstick 101 38 mm 3 992 in G 99 90 red in H 4 4 in Square Keyway 7 16 20 UNF 2B in 152 08 mm 5 987 in Engine Mounting l 38 10 m in 155 58 mm 6 125 in K Oll Filter L Surface M Mounting Surface SE er Semen ne MOMAR ija 460 3 697 In 52 75 mm 2 077 in Oil Drain Plug Q Oil Filter 51 0 mm 2 008 in S 89 0 mm 3 504 in T 3 8 in NPT U 12 28 mm 0 483 in Rectifier Regulator 10 KohlerEngines com 24 690 01 Rev K Engine Dimensions with Low Profile Air Cleaner PTO Side Specifications A U 335 04 mm 13 19 in 122 10 mm 4 807 in S9 IUe MOURBRO 75 42 mm 2 969 in Lift Strap Oil Fill Location 30 WA cer 5 16 24 UNC 2B in ad 12 136 m Mit 135 Way d 0 807 in Deep p 127 mm 5 0 in B C 3 8 16 UNC 2B in 21 mm
26. O2S Heater Circuit Low Voltage Condition System voltage too low open connection or faulty sensor Conclusion Engine Wiring Harness Related e Pin circuit wiring or connectors ECU black pin 7 or broken wire Oxygen Sensor Related e Sensor connector or wiring problem Poor system ground from ECU to engine or battery to engine Code 0032 Component Oxygen Sensor Heater Fault O2S Heater Circuit High Voltage Condition System voltage too high shorted connection or faulty sensor Conclusion Oxygen Sensor Related e Sensor connector or wiring problem e Sensor damaged e Pin circuit wiring or connectors at Black TA ECU Related e ECU to harness connection problem 24 690 01 Rev K KohlerEngines com 51 EFI SYSTEM ECH Code 0107 Code 0113 Component Manifold Absolute Pressure MAP or Component Intake Air Temperature IAT or TMAP TMAP Sensor Sensor Fault MAP or TMAP Circuit Low Voltage or Fault Intake Air Temperature IAT or TMAP Open Sensor Circuit High Voltage or Open Condition Intake manifold leak open connection or Condition Shorted connection faulty sensor broken faulty sensor wire or connection Conclusion MAP or TMAP Sensor Related Conclusion Temperature IAT or TMAP Sensor e Sensor malfunction Related e Vacuum leaks
27. Position Sensor TPS Component ECU Fault Unrecognizable signal is being sent from Fault ECU is unable to recognize or process sensor too high too low inconsistent signals from its memory Condition A limp home operating mode occurs Condition Engine will not run with an overall decrease in operating Conclusion ECU internal memory problem performance and efficiency Fuel delivery LM is based upon oxygen sensor and five e Diagnosable only through elimination mapped values only Rich running of all other system component faults black smoke will occur until closed loop operation is initiated A stumble or Code 24 Will not blink out misfire on hard acceleration and or erratic Component Engine Speed Sensor operation may be exhibited SS Fault No tooth signal from speed sensor MIL e Sensor connector or wiring Condition None engine will not start or run as ECU e Sieg output aS i E S is unable to estimate speed irt grease oil wear or breather tube iE position must be to side opposite Conclusion Engine Speed Sensor Related TPS e Sensor connector or wiring e Sensor loose on throttle body manifold e Sensor loose or air gap incorrect Throttle Body Related Speed Sensor Wheel Related e Throttle shaft or bearings worn e Damaged teeth damaged e Gap section not registering Engine Wiring Harness Related SR 35 Pin MA 1 7 Metal Cased ECU Engine Wiring Harness Related e P
28. Q o 14 Injector 1 Output 710 O 15 Injector 2 Output ai O o 16 Not Used 17 Diagnostic Line 3 o 9 18 Throttle Position Sensor Supply Voltage OO oO 19 Battery Ground o o 20 Oxygen Sensor Input 21 Battery Ground Secondary o o 22 Not Used O Oo 23 Not Used o 0 24 Not Used 25 Safety Switch Input o Q 26 Not Used O O 27 Not Used 28 Main Relay Output 29 Malfunction Indicator Light MIL 30 Ignition Coil 1 Output 31 Ignition Coil 2 Output 32 Not Used 78 KohlerEngines com 24 690 01 Rev K EFI SYSTEM BOSCH pue p suid Sd 0 sas eu Buypass seunbe1uojsjo MI Sd OU JO IPIS jjeus ajjoJuj eui WO Panen Se ojoJuj UOdO 9pIM 0 am Weu Sd 34 jo UONE AAJ 20 si UMOYS uoip auuo SdL 1sues uotysod HO ay AL 19 beyon uues pio e YM 3pA6 2p AIL 01 si eBeyo Buyjesedo jewsoN Jejeed u paw suo 009 Ajeje uxoadde jo Joysjse e sembe siu pesn eque Qa vu Oz e Apeuondo dwe juessepue ui vSz 0 AZI e que Um dwej 1016216 uogounyreyw un HTW uaurasuv uw aed pajsi e eq o1 9 9 01 pue 5 suid sama josues paads AL 99 s m HR pay oeds asimuayjo seau Bupjueis Bump uopesado N33 sut 10 wn vatur AL eq jsnw eBeyon waiss eut Buyers Duung Kio wa ui saydepe eu urejure ui 0j vui Z jo NEIE juana e uj As 19 aBeyon usjsKs wnwiuw e urejureui snu Ajeneq eu uonejedo ui jou ueuM 40j2euuo je uj2ere au wa eme ebeujejp jedoud 9eIJI28j OF UMOP SS9UIBU BIMA ILJ UUM pajunow si Bujsnou NOF euj jeu
29. Replace sensor Improper fueling Correct fueling Incorrect or contaminated fuel Use high guality fuel Excessive engine oil consumption causing exhaust contamination or other exhaust side contamination Correct engine condition Heater circuit open shorted or out of specification Repair short in harness wires replace sensor 24 690 01 Rev K KohlerEngines com 45 EFI SYSTEM ECH A WARNING Explosive Fuel can cause fires and severe burns Fuel Injectors 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 Details A Electrical Connection B Upper O ring C Solenoid Winding D Armature E Valve Housing F Valve Seat G Valve End H Lower O ring l Director Plate 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 NOTE When cranking engine with injectors disconnected fault codes will be registered in ECU and will need to be cleared using software fault clear or an ECU Reset and TPS Learn Procedure Injector problems
30. SI popio tys 3 i zao 095 poo ya su ES e 0390000 YOYIDOH 11Y NDJ Uld SE 3 H aa PUnoug 995 E ch 9 Lf K dw Bam 1V8 am mo e a eu 7 8 S daat d 58 EI punoJ9 935 punoug pioius L ESS ee lef ou We 30018 Jong posn 20 Paci Brod Judg Smd Jods POH MAAS a ze Zerf bu men 1e puno S39D3uo pa E le 1109 NE B iad 75 KohlerEngines com 24 690 01 Rev K EFI SYSTEM BOSCH 24 Pin MSE 1 0 Plastic Cased ECU Systems Pin Component Permanent Battery Voltage Switched Ignition Voltage Safety Switch Throttle Position Sensor TPS and Temperature Sensor Ground Not Used Oil Temperature Sensor Input Not Used Throttle Position Sensor TPS Input ON DOOR WD A 9 Speed Sensor Input 10 Speed Sensor Ground 11 Oxygen Sensor Input 12 Not Used Oxygen Sensor Ground if needed 13 Diagnostic Line 14 Throttle Position Supply Voltage 15 Battery Ground 16 Injector 1 Output 17 Injector 2 Output 18 Main Relay Output 19 Malfunction Indicator Light MIL 20 Not Used Tach Output if needed 21 Not Used 22 Ignition Coil 1 Output 23 Ignition Coil 22 Output 24 TPS Initialization Terminal o o Oo O o O O le o Oo O O 76 KohlerEngines com 24 690 01 Rev K EF
31. START OF TEST FOR RETEST KEY ON MALFUNCTION INDICATOR LIGHT NO REFER TO DIAGNOSTIC AID 1 SYSTEM POWER REFER TO DIAGNOSTIC FAULT CODE SUMMARY CLEAR CODES REFER TO DIAGNOSTIC AID 3 RUN ON ARE FAULT CODES PRESENT DOES ENGINE START YES NO NO YES OPERATE AT VARIOUS SPEED LOAD CONDITIONS ARE FAULT CODES PRESENT CRANK ENGINE DOES MIL GO OFF REFER TO DIAGNOSTIC FAULT CODE SUMMARY CLEAR CODES NO NO END OF TEST REFER TO DIAGNOSTIC AID 4 CRANKSHAFT POSITION SENSOR REFER TO DIAGNOSTIC AID 5 FUEL PUMP NO REFER TO DIAGNOSTIC AID 6 IGNITION SYSTEM YES KEY OFF AND KEY ON LISTEN FOR FUEL PUMP DOES FUEL PUMP CYCL ON THEN OFF AFTER 1 2 SECONDS YES NO WHILE CRANKING CHECK IGNITION SYSTEM PROCEED TO START OF TEST FOR RETEST YES WHILE CRANKING CHECK INJECTOR FUEL DELIVERY WET SPARK PLUG NO REFER TO DIAGNOSTIC AID 7 FUEL SYSTEM ELECTRICAL YES INSTALL IN LINE PRESSURE GAUGE AND KEY ON REFER TO DIAGNOSTIC AID 8 IN SPECIFICATION NO FUEL SYSTEM yes REFER TO DIAGNOSTIC AID 9 BASIC ENGINE 1 After turning key to OFF wait 10 seconds before turning to ON to allow ECU to go to sleep 2 Fuel pump module can be heard or a vibration can be felt to establish pump cycle Fuel pump module will run for one 4 6 second cycle when ECU wakes up after being asleep 58 KohlerEngines com 24 690 01 R
32. any lubricants Presence of lubricants can cause flywheel to be over stressed and damaged when screw is torqued to specifications Make sure flywheel key is installed properly in keyway Flywheel can become cracked or damaged if key is not properly installed taper 2 Install flywheel onto crankshaft being careful not to shift woodruff key 3 Install screw and washer 126 4 Use a flywheel strap wrench or holding tool to hold flywheel Torque screw securing flywheel to crankshaft to 71 6 N m 52 8 ft Ib Install Fan NOTE Position locating tabs on back of fan in locating 1 holes of flywheel Install fan onto flywheel using screws engines with plastic grass screen Engines with a metal grass screen will leave fan loosely assembled Torque screws to 9 9 N m 88 in Ib KohlerEngines com 24 690 01 Rev K Install Hydraulic Lifters Reassembly NOTE Hydraulic lifters should always be installed in same position as before disassembly Exhaust lifters are located on output shaft side of engine while intake lifters are located on fan side of engine Cylinder numbers are embossed on top of crankcase and each cylinder head 1 See Servicing Hydraulic Lifters in Disassembly Inspection and Service 2 Apply camshaft lubricant to bottom surface of each lifter Lubricate hydraulic lifters and lifter bores in crankcase with engine oil 3 Note mark or tag identifying hydraulic lifters as either
33. as primary means of detecting load Data is used to calculate air density and determine engine s mass air flow rate which in turn determines required ideal fueling MAP also stores instant barometric pressure reading when key is turned ON Later engines have a Temperature Manifold Absolute Pressure TMAP sensor This is an integrated sensor that checks both intake air temperature and manifold absolute pressure This combined sensor is located in intake manifold 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 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 up to 1 0 volt is generated and sent to ECU Voltage signal tells ECU if engine is straying from ideal fuel mixture and ECU then adjusts injector pulse accordingly Oxygen sensor functions after being heated to a minimum of 400 C 752 F A heater inside sensor heats electrode to optimum temperature in about 10 seconds Oxygen sensor receives ground through wire eliminating need for proper grounding through muffler If problems indicate a bad oxygen sensor check all connections and wire harness Oxygen sensor can also be contaminated by leaded fuel certain RTV and or other
34. body off intake manifold Breather Tube gt KohlerEngines com 107 Disassembly Inspection and Service External Engine Components v A Debris Screen B Blower Housing Outer Baffle D Breather Cover E Oil Sentry F Si atr aas G Inner Baffle H Debris Screen Guard Remove Debris Screen Guard Remove screws and spacers securing debris screen guard and remove debris screen guard Remove Debris Screen NOTE Fan will be loose but cannot be removed until after blower housing is removed 1 Remove socket head cap screws securing metal grass screen and remove screen 2 Remove spacers paying attention to curvature of spring washers between spacers and fan 3 If there is a plastic grass screen attached to fan remove screws securing grass screen Removing screen will expose screws fastening fan to flywheel Remove Outer Baffles and Blower Housing NOTE Some engines may have 2 fuses mounted to a bracket above ECU and a third in line fuse by rectifier regulator 1 Disconnect plug from rectifier regulator 2 Remove silver or green plated rectifier regulator ground strap ground lead screw fastened to crankcase Rectifier regulator does not have to be detached from blower housing 3 Disconnect 3 fuse connectors on outer baffle and allow them to hang 108 KohlerEngines com 4 Remove screws securing outer baffles Note location of any lifting strap an
35. control only Until fault is detected and efficiency registered by ECU engine will run rich Conclusion Engine Wiring Harness Related if oxygen sensor is shorted to ground EE or lean if it is shorted to battery voltage e Pin circuit wiring or connectors After fault is detected performance can Pin 10 for 35 Pin MA 1 7 vary depending on cause If performance Metal Cased ECU is pretty good problem is probably with Pin 11 for 24 Pin MSE 1 0 the oxygen sensor wiring or connectors Plastic Cased ECU If engine is still running rich laboring e P short on power or lean popping or A 20 a eee 1 1 misfiring fuel mixture is suspect astic Case probably incorrect TPS initialization or low fuel pie Oxygen Sensor Related Conclusion TPS Initialization Incorrect e Lean condition check oxygen sensor signal with VOA and see Oxygen Sensor section Engine Wiring Harness Related e Pin circuit wiring or connectors Pin 10 for 35 Pin MA 1 7 Metal Cased ECU Pin 11 for 24 Pin MSE 1 0 Plastic Cased ECU Pin 20 for 32 Pin MSE 1 1 Plastic Cased ECU 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 e Sensor connector or wiring problem e Sensor contaminated or damaged e Sensor below minimu
36. 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 second intervals allowing a 60 second cool down period between cranking intervals until engine starts ELECTRICAL COMPONENTS Three different styles of ECU s have been utilized in EFI production First style is easily identified by its metal case with large 35 pin connector block and also as MA 1 7 Second and third styles have plastic cases but are smaller in overall size These have either a 24 pin or 32 pin connector block and identified as MSE 1 0 or MSE 1 1 respectively Basic function and operating control remains same between three however due to differences in internal circuitry as well as wiring harness none of ECU s are interchangeable Certain individual service troubleshooting procedures also apply where applicable they are covered individually as 35 Pin MA 1 7 Metal Cased ECU 24 Pin MSE 1 0 Plastic Cased ECU or 32 Pin MSE 1 1 Plastic Cased ECU 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
37. e Exhaust system leak muffler flange oxygen sensor mounting boss etc e Fuel in crankcase oil e Altitude e Blocked or restricted fuel return circuit to tank 86 KohlerEngines com 24 690 01 Rev K EFI SYSTEM BOSCH Code 43 and 44 32 Pin MSE 1 1 Plastic Cased Code 42 Component Engine Oil Temperature Sensor Fault 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 35 Pin MA 1 7 Metal Cased ECU e Pin circuits 14 and or 27A damaged wires connectors or routed near noisy signal coils alternator etc e ECU to harness connection problem Engine Wiring Harness Related 24 Pin MSE 1 0 Plastic Cased ECU 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 Engine Wiring Harness Related 32 Pin MSE 1 1 Plastic Cased ECU 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 ECU only Component TPS Auto Learn initialization function failed throttle angle out of learnin
38. e Switched ECU power circuit problem 35 Pin MA 1 7 Metal Cased ECU Pin circuit 17 24 Pin MSE 1 0 Plastic Cased ECU Pin circuit 2 32 Pin MSE 1 1 Plastic Cased ECU Pin circuit 2 e ECU grounds e 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 Oil Temperature Sensor e Code 43 TPS Auto Learn Initialization Function Below Min Limit 32 Pin MSE 1 1 Plastic Cased ECU only e Code 44 TPS Auto Learn Initialization Function Above Max Limit 32 Pin MSE 1 1 Plastic Cased ECU only e Code 51 Injector 1 32 Pin MSE 1 1 Plastic Cased ECU only e Code 52 Injector 2 32 Pin MSE 1 1 Plastic Cased ECU only e Code 55 MIL Light 32 Pin MSE 1 1 Plastic Cased ECU only e Code 56 Pump Relay 32 Pin MSE 1 1 Plastic Cased ECU only 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 MIL when engine is running Code 21 Engine Speed Synchronization Code 22 Throttle Position Sens
39. 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 50 60 C 122 140 F e Oxygen sensor has warmed sufficiently to provide a signal minimum 400 C 752 F e Engine operation is at a steady state not starting warming up accelerating etc During closed loop operation ECU has ability to readjust and learn 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 60 70 C 140 158 F to properly adapt These adaptive values are maintained as long as ECU is not reset During certain operating periods such as cold starts warm up acceleration high load etc a richer air fuel ratio is required and system operates in an open loop mode In open loop operation oxygen sensor output is used to ensure engine is running rich and controlling adjustments are based on primary sensor signals and programmed maps only This system operates open loop whe
40. 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 cylinder 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 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 2 flame fronts which meet and explode to create extreme hammering pressures on a KohlerEngines com 117 Disassembly Inspection and Service 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 an
41. from loose manifold or e Sensor wiring or connection SCH Engine Wiring Harness Related Wire Harness Related e Pin circuits ECU Black pin 10 and 8 e Poor grounding or open circuit may be damaged e Wire harness and connectors loose e ECU to harness connection problem or damaged or corroded broken wire e Pin circuit wiring or connectors at Black 10 11 and 16 Code 0117 Component Coolant Oil Sensor Bad TPS Learn Fault Coolant Oil Temperature Sensor Circuit Low Voltage Code 0108 Condition Shorted connection faulty sensor or Component Manifold Absolute Pressure MAP or shorted wire TMAP Sensor Conclusion Temperature Sensor Related Fault MAP or TMAP Circuit High Voltage SEENEN Condition Intake manifold leak shorted connection Engine Wiring Harness Related or faulty sensor e Pin circuits Black 10 and Black 14 Conclusion MAP or TMAP Sensor Related maybe damaged or routed near noisy e Sensor malfunction signal coils stator etc e Vacuum leaks from loose manifold or e ECU to harness connection problem sensor Code 0118 Wire Harness Related Component Coolant Oil Sensor e Poor grounding PES e Pin circuit wiring or connectors at Black Fault Coolant Oil Temperature Sensor Circuit 11 High Voltage or Open Condition Shorted connection faulty sensor open Bad TPS Learn connection or broken wire Conclusion Temperature Sensor Related Code 0112 e Sensor wiring or connection t Intake Ai Componen ou nd T
42. 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 servicing 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 e Never attempt to service any fuel system component while engine is running or ignition switch is ON e Do not use compressed air if system is open Cover any parts removed and wrap any open joints with plastic if they will remain open for any length of time New parts should be removed from their protective packaging just prior to installation e Avoid direct water or spray contact with system components e Do not disconnect or reconnect ECU wiring harness connector or any individual components with ignition on 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 e Never start engine when cables are loose or poorly connected to battery terminals Never disconnect b
43. in a lean starting condition If required testing fuel pump and relay may be conducted 1 Connect black hose of Pressure Tester part of EFI Service Kit see Tools and Aids to test valve in fuel rail Route clear hose into a portable gasoline container or equipment fuel tank 2 Tum on key switch to activate pump and check System pressure on gauge If system pressure 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 70 KohlerEngines com 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 4 f voltage at plug was go
44. keeping it attached at fuel pump module Do not cut Oetiker clamp unless fuel line or fuel pump module are being replaced 3 Disconnect yellow electrical connector by pulling up on grey tab to release 4 Wrap a shop towel completely around high pressure fuel line connector 5 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 6 Disconnect vent hose from top of fuel pump module 7 Remove screws securing fuel pump module baffle which pump was mounted to ECU ECH EFI Remove Electronic Control Unit ECU cs E Z iz A Electronic Control B ECU Bracket Unit ECU C Starter 1 Remove screws securing ECU to bracket 2 Disconnect Black and Grey electrical connectors from ECU Remove Electronic Control Unit Bracket and Electric Starter Motor 1 Disconnect leads from starter 2 Remove screws 24 690 01 Rev K Throttle Body Components B Throttle Position A Throttle Body Sensor TPS C Intake Air Temperature D IAT Sensor 1 Disconnect breather tube from throttle body 2 On earlier engines with separate intake air temperature IAT and MAP sensors disconnect IAT sensor from throttle body 3 Disconnect throttle position sensor connector Disconnect vent hose from throttle body 5 Slide throttle
45. loose or incorrect air gap e Flywheel key sheared Speed Sensor Ring Gear Related e Damaged teeth e Varying gap gear loose out of alignment Engine Wiring Harness Related 35 Pin MA 1 7 Metal Cased ECU e Pin circuits 3 and or 21 wiring or connectors e Shielding for pin circuits 3 and or 21 damaged or not properly grounded e Poor or improper grounds in system battery ECU oxygen sensor shielding fuel pump ignition output e Pin circuits 3 and or 21 routed near noisy electrical signals coils spark plug lead plug connector 24 690 01 Rev K KohlerEngines com 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 Engine Wiring Harness Related 32 Pin MSE 1 1 Plastic Cased ECU 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 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 83 EFI SYSTEM BOSCH Code 22 Code 23 Component Throttle
46. on Possible causes e Fuel pump fuse e Fuel pump circuit problem 35 Pin MA 1 7 Metal Cased ECU Circuits 43 44 and relay 24 Pin MSE 1 0 Plastic Cased ECU Circuits 30 87 and relay 32 Pin MSE 1 1 Plastic Cased ECU Circuits 30 87 and relay e Fuel pump Diagnostic Aid 46 RELAY relay not operating Possible causes e Safety switches circuit s problem ae Pin MA 1 7 Metal Cased ECU Circuits 41 and on Pin MSE 1 0 Plastic Cased ECU Circuit 3 32 Pin MSE 1 1 Plastic Cased ECU Circuit 25 e Relay circuit s problem 35 Pin MA 1 7 Metal Cased ECU Circuits 28 41 and 41A 24 Pin MSE 1 0 Plastic Cased ECU Circuits 18 85 30 and 87 90 KohlerEngines com 32 Pin MSE 1 1 Plastic Cased ECU Circuits 28 85 30 and 87 e Relay e ECU grounds e ECU Diagnostic Aid 7 IGNITION SYSTEM no spark Possible causes e Spark plug e Plug wire e Coil e Coil circuit s 35 Pin MA 1 7 Metal Cased ECU Circuits 1 19 40 40A 43 and relay 24 Pin MSE 1 0 Plastic Cased ECU Circuits 22 23 65 66 30 and relay 32 Pin MSE 1 1 Plastic Cased ECU Circuits 30 31 65 66 relay and relay circuit 30 e ECU grounds e ECU Diagnostic Aid 8 FUEL SYSTEM ELECTRICAL no fuel delivery Possible causes e No fuel e Air in fuel rail e Fuel valve shut off e Fuel filter line plugged e Injector circuit s 35 Pin MA 1 7 Metal
47. reestablish baseline relationship between ECU and TPS Engine oil temperature sensor is used by system to help determine fuel requirements for starting a cold engine 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 24 690 01 Rev K EFI SYSTEM BOSCH 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 suffi
48. relay e Circuit controlling fuel pump relay damaged damaged Code 55 32 Pin MSE 1 1 Plastic Cased ECU only 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 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 88 KohlerEngines com 24 690 01 Rev K Code 56 32 Pin MSE 1 1 Plastic Cased ECU only 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 wir
49. remove connecting rod and piston assembly from cylinder bore 3 Repeat above procedure for other connecting rod and piston assembly 4 Remove piston pin from piston for inspection Use a small screwdriver to pry pin retainer out of groove 24 690 01 Rev K Inspection Piston and Rings Components and Details i Top Compression A Piston B al Middle Compression E Ring D Rails E Expander F Oil GE 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 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
50. replace shaft if worn or damaged Appropriate TPS Initialization Procedure must be performed after any throttle shaft service Idle Speed Adjustment RPM Adjustment Procedure 1 Make sure there are no fault codes present in ECU memory 2 Start engine and allow it to fully 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 24 690 01 Rev K EFI SYSTEM BOSCH Idle Speed Screw Dampening Spring Idle Speed Screw Details 1 3 mm 0 039 0 117 in Exposed Length Off End Of Adjustment Screw A Dampening Spring B Some Models C Idle Speed Screw A small dampening spring is attached to end of idle speed screw of some EFI engines to help stabilize no load operating speeds Idle speed adjustment procedure remains same for engines with or without a dampening spring Typically no periodic servicing is necessary in this area If however removal replacement of dampening spring is required reinstall it as follows 1 Thread spring onto end of idle screw leaving 1 3
51. segments Continuity must exist between all or armature is bad Check for continuity between armature coil segments and commutator segments There should be no continuity If continuity exists between any 2 armature is bad Check armature windings insulation for shorting ft 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 2 24 690 01 Rev K Perform steps 1 5 in Starter Disassembly Remove screws securing brush holder assembly to end cap plate Note orientation for reassembly later Discard old brush holder assembly 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 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 System 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 10 KohlerEngines com lever will be flush or below machined surface of housing Apply drive lubricant to armature shaft splines Install drive pinion onto armature shaft Inst
52. 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 KohlerEngines com 31 EFI SYSTEM ECH Earlier engines have a separate intake air temperature IAT sensor located in throttle body and a manifold absolute pressure MAP sensor Later engines have a combined temperature manifold absolute pressure TMAP sensor Intake Air Temperature IAT sensor is a thermally sensitive resistor that exhibits a change in electrical resistance with a change in its temperature When sensor is cold resistance of sensor is high As sensor warms up resistance drops and voltage signal increases From voltage signal ECU can determine temperature of intake air Purpose of an air temperature sensor is to help ECU calculate air density Higher air temperature less dense air becomes As air becomes less dense ECU knows that it needs to lessen fuel flow to achieve correct air fuel ratio If fuel ratio was not changed engine would become rich possibly losing power and consuming more fuel Manifold absolute pressure MAP sensor provides immediate manifold pressure information to ECU MAP measures difference in pressure between outside atmosphere and vacuum level inside intake manifold and monitors pressure in manifold
53. tighten securely 8 Start engine check for oil leaks Stop engine correct leaks Recheck oil level 9 Dispose of used oil and filter in accordance with local ordinances OIL COOLER if equipped 1 Clean fins with a brush or compressed air 2 Remove screws securing oil cooler and tilt to clean back side 3 Reinstall oil cooler and torque to 2 2 N m 20 in Ib OIL SENTRY if equipped This switch is designed 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 breather cover On engines not equipped with Oil Sentry installation hole is sealed with a 1 8 27 N R T F pipe plug 24 690 01 Rev K Lubrication System 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 breather cover 3 Torque switch to 4 5 N m 40 in Ib Testing Compressed air a pressure regulator pressure gauge and a continuity tester are required to test switch ECH Models Normally Closed 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 increas
54. turn ignition switch off and replace injector as follows Depressurize fuel system following procedure in fuel warning on page Remove fuel rail mounting screws Clean any dirt accumulation from sealing mounting area of faulty injector s and disconnect electrical connector s Pull retaining clip off top of injector s Disconnect fuel rail and remove injector s from manifold EFI SYSTEM BOSCH 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 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 the
55. 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 if injectors are operating 46 KohlerEngines com 1 With engine running at idle listen for a buzzing or clicking sound 2 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 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 into one connector 2 Make sure all safety switch requirements are met Crank engine and check for flashing of test light Turn key OFF for at least 10 seconds between tests to allow ECU to go to sleep and reawake 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 11 13 O If injector resistance is correct check whether connector and injector terminals are making a good connection If resistance is not correct replace injector 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
56. voltage e Problem in wiring harness e Problem in wiring harness e ECU to harness connection problem e ECU to harness connection problem Systems Related Systems Related e Ignition spark plug plug wire ignition e Ignition spark plug plug wire ignition coil coil e Fuel fuel type quality injector fuel e Fuel fuel type quality injector fuel pressure too high fuel pump module or pressure too low fuel pump module or lift pump lift pump e Combustion air air cleaner dirty e Combustion air air cleaner dirty restricted restricted intake leak throttle bores e Base engine problem rings valves e Base engine problem rings valves e Fuel in crankcase oil e Exhaust system leak muffler flange e Fuel pump module is over filled oxygen sensor mounting boss etc e Lift pump diaphragm is ruptured e Fuel in crankcase oil 54 KohlerEngines com 24 690 01 Rev K EFI SYSTEM ECH Code 0174 Code 0202 Component Fuel System Component Fuel Injector Fault Lean fuel condition Fault Injector 2 Circuit Malfunction Condition Fuel inlet screen filter plugged low Condition Injector damaged or faulty shorted or pressure at high pressure fuel line TPS open connection malfunction shorted connection or faulty Conclusion Injector Related sensor e Injector coil shorted or opened Conclusion TPS Learn Incorrect e Lean condition check oxygen se
57. 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 is a sealed non serviceable assembly If Fault Code diagnosis indicates a problem within this area check and test as follows 1 Check mounting and air gap of sensor It must be 1 5 mm x 0 25 mm 0 059 0 010 in 2 Inspect wiring and connections for damage or problems 24 690 01 Rev K EFI SYSTEM BOSCH 3 Make sure engine has resistor type spark plugs Disconnect main harness connector from ECU 5 Connect an ohmmeter between designated pin terminals in plug 35 Pin MA 1 7 Metal Cased ECU 3 and 21 pin terminals 24 Pin MSE 1 0 Plastic Cased ECU 9 and 10 pin terminals 32 Pin MSE 1 1 Plastic Cased ECU 9 and 10 pin terminals See page 26 according to ECU style A resistance value of 750 1000 Q at room temperature 20 C 68 F should be obtained If resistance is correct check 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 bet
58. 0 RPM idle speed adjustment or 4 Problem with ECU or TPS When initialization procedure has been successfully completed turn off key switch remove jumper wire or connector and remove rubber band from throttle lever Disconnect negative battery cable temporarily to clear all learned adjustments Reconnect battery cable and all external loads Readjust idle speed to equipment manufacturer s specified setting and recheck high speed no load RPM setting Observe overall performance TPS Initialization Procedure For 32 Pin MSE 1 1 Plastic Cased ECU Only Auto Learn Initialization 1 Check that basic engine all sensors fuel fuel pressure and battery are good and functionally within specifications Important 2 24 690 01 Rev K 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 Remove jumper wire or plug from service connector plug in w
59. 1 Rev K EFI SYSTEM ECH Crankshaft Position Sensor Contacting Brush Type TPS Resistance Table A Earlier Design Bracket B Later Design Bracket A sealed non serviceable assembly If Fault Code diagnosis indicates a problem within this area test and correct as follows 1 Check mounting and air gap of crankshaft position sensor Earlier design bracket has slots to set air gap of 0 20 0 70 mm 0 008 0 027 in Later design bracket is not adjustable but if gap is greater than 2 794 mm 0 110 in check bracket or sensor for damage 2 Inspect wiring and connections for damage or problems 3 Make sure engine has resistor type spark plugs Disconnect Black connector from ECU 5 Connect an ohmmeter between 4 and 13 pin terminals A resistance value of 325 395 O at room temperature 20 C 68 F should be obtained If resistance is correct check mounting air gap flywheel teeth damage run out etc and flywheel key 6 Disconnect crankshaft position sensor connector from wiring harness Test resistance between terminals A reading of 325 395 O should again be obtained a If resistance is incorrect remove screws securing sensor to mounting bracket and replace sensor b If resistance in step 5 was incorrect but resistance of sensor alone was correct test wire harness circuits between sensor connector terminals and corresponding pin terminals 4 and 13 in main connect
60. 14 15 24 690 01 Rev K 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 Remove blower housing mounting screws Note location of plated silver screw attaching rectifier regulator ground lead Remove blower housing Thoroughly clean area around and including throttle body manifold and injectors Disconnect throttle linkage and damper spring from throttle lever Disconnect TPS lead from harness 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 Position 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 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
61. 3 N m 20 in Ib into used holes Fastener Torque 10 7 N m 95 in Ib into new holes 7 3 N m 65 in Ib into used holes 3Values are in Metric units Values in parentheses are English equivalents gt Lubricate threads with engine oil prior to assembly 24 690 01 Rev K KohlerEngines com 15 Specifications TORQUE SPECIFICATIONS ECH630 ECH680 ECH730 ECH749 CH26 CH735 CH745 Starter Assembly Thru Bolt 5 6 9 0 N m 49 79 in Ib Nippondenso Solenoid Shift Delco Remy Solenoid Shift 40 84 in Ib Mounting Screw 16 0 N m 142 in Ib 3 4 5 7 5 Nm 5 6 9 0 N m 49 79 in Ib 15 3 N m 135 in Ib Brush Holder Mounting Screw Delco Remy Starter 2 5 3 3 N m 22 29 in Ib 2 5 3 3 N m 22 29 in Ib Starter Solenoid Mounting Hardware Nippondenso Starter Delco Remy Starter 4 0 6 0 N m 35 53 in Ib 33 53 79 in Ib 35 53 in Ib Nut Positive Brush Lead 8 0 11 0 N m 71 97 in Ib 6 0 9 0 N 4 0 6 0 N N N Nippondenso Starter 8 0 12 0 N m 71 106 in Ib Delco Remy Starter 8 0 11 0 N m 71 97 in Ib Stator Mounting Screw 6 2 N m 55 in Ib into new holes 4 0 N m 35 in Ib into used holes abu LE Valve Cover Fastener 6 2 N m 55 in Ib Gasket Style Cover 3 4 N m 30 in Ib Black O Ring Style Cover w Shoulder Screws 5 6 N m 50 in Ib w Flange Screws and Spacers 9 9 N m 88 in Ib
62. 5 761 40 S SE Tools KLR 82411 SE Tools KLR 82416 Triad OHC Timing Tool Set For holding cam gears and crankshaft in timed position while installing timing belt Kohler 28 761 01 S Valve Guide Reamer K and M Series For properly sizing valve guides after installation Design Technology Inc DTI K828 Valve Guide Reamer O S Command Series 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 For hand reaming using Kohler 25 455 12 S reamer AIDS Description Kohler 25 455 12 S Design Technology Inc 8 Source Part No Camshaft Lubricant Valspar ZZ613 Kohler 25 357 14 S Dielectric Grease GE Novaguard G661 Kohler 25 357 11 S Dielectric Grease Loctite 51360 Kohler Electric Starter Drive Lubricant Inertia Drive Kohler 52 357 01 S Kohler Electric Starter Drive Lubricant Solenoid Shift Kohler 52 357 02 S RTV Silicone Sealant Loctite 59009 Heavy Body in 4 oz aerosol dispenser Only oxime based oil resistant RTV sealants such as those listed are approved for use Loctite Nos 5900 or 5910 are recommended for best sealing characteristics Loctite Ultra Copper 59207 Kohler 25 597 07 S Loctite 59109 Loctite Ultra Black 598 Loctite Ultra Blue 5877 Spline Drive Lubricant Kohler 25 357 12 S 24 690 01 Rev K Kohler
63. 7 in Pin Bore I D New 17 006 17 012 mm 0 6695 0 6698 in Max Wear Limit 17 025 mm 0 6703 in Pin O D New 16 995 17 000 mm 0 6691 0 6693 in Max Wear Limit 16 994 mm 0 6691 in Values are in Metric units Values in parentheses are English equivalents 18 KohlerEngines com 24 690 01 Rev K CLEARANCE SPECIFICATIONS ECH630 ECH680 Piston Piston Rings and Piston Pin Style A continued Specifications ECH730 ECH749 CH26 CH735 CH745 Top Compression Ring to Groove Side Clearance 0 050 0 095 mm 0 0019 0 0037 in 0 025 0 048 mm 0 0010 0 0019 in Middle Compression Ring to Groove Side Clearance 0 030 0 075 mm 0 0012 0 00307 in 0 015 0 037 mm 0 0006 0 0015 in Oil Control Ring to Groove Side Clearance 0 010 0 011 mm 0 0004 0 0043 in 0 026 0 176 mm 0 0010 0 0070 in Top and Center Compression Ring End Gap New Bore Used Bore Max 0 80 mm 0 0315 in 0 25 0 56 mm 0 0100 0 0224 in 0 94 mm 0 037 in Thrust Face O D 79 943 79 961 mm 3 1473 3 1480 in 82 949 82 967 mm 3 2657 3 2664 in Max Wear Limit 79 816 mm 3 1423 in 82 822 mm 3 2606 in Piston Thrust Face to Cylinder Bore Running Clearance New Piston Style B PON 0 039 0 082 mm 0 0015 0 0032 in Piston to Piston Pin Running Clearance 0 006 0 017 mm 0 0002 0 0007 in Max Wear Limit Pin Bore I D New 17
64. 8 93 mm E 230 20 mm 9 063 in F 130 0 mm 5 118 in G 3 475 in H 11 769 in 77 17 mm 67 19 mm 277 22 mm 10 914 in J 135 0 mm 5 315 in K 3 038 in Spark Plug L 2 645 in Spark Removal Plug Boot Removal 37 15 mm 320 89 mm 315 14 mm M 1 463in Spark Plug N 12 633 in Spark Plug O 12 407 in Spark P 20 Boot Removal Plug Boot Removal Engine Mounti 4X 210 Q id oo R 0 A06 nr S 1184 20 mm 7 252 in T Engine Center Line 15 70 mm U 92 10 mm 3 626 in v Center Line Mounting w 134 80 mm 5 307 in X 0 618 in Oil Filter Removal 315 25 mm 25 46 mm Y Crankshaft Center Line Z 12412 in Spark Plug AA 14 mm 2 182 AB 1 002 in Spark Boot Removal p 9 Plug Boot Removal 39 66 mm 1 562 in AC Fuel Filter AD Spark Plug Removal AE Fuel Pump 24 690 01 Rev K KohlerEngines com Specifications Engine Dimensions with Heavy Duty Air Cleaner Oil Filter Side D pu Mi T 30 0 mm 1 181 in soc B 209 88 mm 8 263 in C 52 43 mm 2 064 in Spark Plug Center 14 624 in geg SE VE Oil Fill G Dipstick 101 38 mm 3 992 in 7 16 20 UNF 2B in 85 50 mm 3 366 in 4 4 in Square Keyway K 622 70 mm 24 516 in 38 10 mm 1 5
65. Cross Shaft Remove camshaft 1 Remove retainer and nylon washer from governor Inspection and Service cross shaft NOTE To prevent repeat failures camshaft and 2 Remove cross shaft through inside of crankcase crankshaft should always be replaced as a set Check lobes of camshaft for wear or damage See Specifications for minimum lift tolerances Measurement must be performed while valve train is still assembled Inspect cam gear for badly worn chipped or missing teeth Replacement of camshaft will be necessary if any of these conditions exist 116 KohlerEngines com 24 690 01 Rev K Governor Cross Shaft Oil Seal Disassembly Inspection and Service Piston and Rings Cross Shaft Oil Seal Details A 2 0 mm 0 0787 in B Governor Cross Shaft Seal If governor cross shaft seal is damaged and or leaks replace it using these following procedures Remove oil seal from crankcase and replace it with a new one Install new seal to depth shown using a seal installer 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 NOTE Cylinders are numbered on crankcase Use numbers to mark each end cap connecting rod and piston for reassembly Do not mix end caps and connecting rods 1 Remove screws securing closest connecting rod end cap Remove end cap 2 Carefully
66. E INTAKE VALVE B LS Dimension Intake Exhaust A Seat Angle 89 89 B Insert O D 36 987 37 013 mm 1 4562 1 4572 in 32 987 33 013 mm 1 2987 1 2997 in C Guide Depth 4 mm 0 1575 in 4 mm 0 1575 in D Guide I D 7 038 7 058 mm 0 2771 0 2779 in 7 038 7 058 mm 0 2771 0 2779 in E Valve Head Diameter 33 37 33 63 mm 1 3138 1 3240 in 29 37 29 63 mm 1 1563 1 1665 in F Valve Face Angle 45 45 G Valve Margin Min 1 5 mm 0 0591 in 6 982 7 000 mm 1 5 mm 0 0591 in H Valve Stem Diameter 0 2749 0 2756 in 6 970 6 988 mm 0 2744 0 2751 in 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 See valve details and specifications 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 excessive corrosion or a wor
67. ECU suppresses injection signals cutting off fuel flow This process repeats itself in rapid succession limiting operation to preset maximum Wiring harness used in EFI system connects electrical components providing current and ground paths for system to operate All input and output signaling occurs through two special all weather connectors that attach and lock to ECU Connectors are Black and Grey and keyed differently to prevent being attached to ECU incorrectly Condition of wiring connectors and terminal connections is essential to system function and performance Corrosion moisture and poor connections are as likely cause of operating problems and system errors as an actual component Refer to Electrical System for additional information EFI system is a 12 VDC negative ground system designed to operate down to a minimum of 6 0 volts If system voltage drops below this level operation of voltage sensitive components such as ECU fuel pump ignition coils 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 I related problems are often caused by wiring harness or connections Even small amounts of corrosion or ox
68. EIS Wai sas o4auarj UN ouas 493525 YO an 03 asop ven abua oy peu IHs 5042 03 psu29v31v paumbas s des upuncuB o pasn si suf deg ji puno4B mausi si al wd pesn sj sosues papoa oag 4t Mine Muy gin maus suy 0 Spang ous suL Jay405 mau yog auffua Oy pauotiiy Gon SET u 40u Laun Ce amou lined U Sand end 3 05465 zoue H 451450 H kad L S31BN SNIINDnDSS Yu apuna JA Dr odg andano TOL lt a indino auch de anding 4201 E andang duv Dag E arno Amay dung et 3nd3ng 40320 UT RA andang i 40339fuy e punoug eg et aoza A ddns Sdi EL aur et paau 4 pungua opquo E andu gaer at C Out YA or Zei andur RA Ki 3004 Sdi E 3ndu q v 3 905 Ki andu dua sen a pas SON EI PUNDJI dua 3 Sai o ouas 493505 3 von Fans usucuJagy Aiddns 48 08 a LN 40322uu0j 9E em A XXX A V XXXX OT sau jesus sas G 77 KohlerEngines com 24 690 01 Rev K EFI SYSTEM BOSCH 32 Pin MSE 1 1 Plastic Cased ECU Systems Pin Component 1 Permanent Battery Voltage 2 Switched Battery Voltage 3 TPS Set Auto Learn Initialization Terminal 4 Throttle Position Sensor TPS and Temperature Sensor Ground 5 Not Used 6 Oil Temperature Sensor Input 110 o 7 Not Used 8 Throttle Position Sensor TPS Input o o 9 Speed Sensor Input 3 0 o 10 Speed Sensor Ground 410 o 11 Not Used slo o 12 Not Used 13 Not Used 6
69. EN 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 No P REFER TO DIAGNOSTIC AID 46 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 REFER TO DIAGNOSTIC AID 9 IN SPECIFICATION FUEL SYSTEM No REFER TO DIAGNOSTIC AID 8 FUEL SYSTEM ELECTRICAL REFER TO DIAGNOSTIC AID 10 BASE ENGINE 24 690 01 Rev K KohlerEngines com 91 Lubrication System This engine uses a full pressure lubrication system which delivers oil under pressure to crankshaft camshaft connecting rod bearing surfaces and hydraulic valve lifters A high efficiency gerotor oil pump maintains high oil flow and oil pressure even at low speeds and high operating temperatures A pressure relief valve limits maximum pressure of system Oil pan must be removed to service oil pickup pressure relief valve and oil pump Lubrication Components A Oil Filter B Back Side C Oil Cooler D Oil Drain Plug E Oil Fill Cap F OilFil Dipstick G Pressure Switch H Oil Sentry OIL RECOMMENDATIONS Refer to Maintenance CHECK OIL LEVEL N
70. Engines com 23 Tools and Aids FLYWHEEL HOLDING TOOL ROCKER ARM CRANKSHAFT TOOL A flywheel holding tool can be made out of an old junk A spanner wrench to lift rocker arms or turn crankshaft flywheel ring gear and used in place of a strap wrench may be made out of an old junk connecting rod 1 Using an abrasive cut off wheel cut out a six tooth 1 Find a used connecting rod from a 10 HP or larger 2 3 24 segment of ring gear as shown Grind off any burrs or sharp edges engine Remove and discard rod cap 2 Remove studs of a Posi Lock rod or grind off Invert segment and place it between ignition bosses cu i steps of a Command rod so joint surface is on crankcase so tool teeth engage flywheel ring CR gear teeth Bosses will lock tool and flywheel in 3 Finda 1 in long capscrew with correct thread size to position for loosening tightening or removing with a match threads in connecting rod puller 4 Use a flat washer with correct LD to slip on capscrew and approximately 1 in O D Assemble capscrew and washer to joint surface of rod KohlerEngines com 24 690 01 Rev K 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 t
71. Exhaust Port 1 Engine Mounting Surface 67 50 mm 2 657 in Muffler Mounting Bosses Center Line Mounting Hole A Dipstick 89 0 mm 3 504 in 51 0 mm 2 008 in Oil Drain Plug 3 8 in 12 28 mm 0 483 in KohlerEngines com Lift Strap 24 690 01 Rev K Specifications Engine Dimensions with Low Profile Air Cleaner Flywheel Side p A O ZT B _ O Vsus ENIM ET oO 4 r 4 TO coo Rem oe OUR Pr poe c V A 7 5 SUD R mi B at EO KE Lee Rf JUL Week E L D N b E 207 5 7 94 og K Ld G YA rn g i A 451 16 mm 17 762 in B 298 93 mm 11769 in C Valve Cover D 12 95 mm 0 510 in 67 19 mm 77 17 mm 37 15 mm E 2 645 in Spark p 3 038 in Spark G 1 463 in Spark H 148 639 in Plug Boot Removal Plug Removal Plug Boot i ji 320 89 mm 315 14 mm e l 3 038 in Spark J 20 K 12 407 in Spark L Engine Mounting Plug Removal Plug Boot Removal M ORARE N 184 20 mm 7 252in O Engine Center Line P 92 10 mm 3 628 in 15 70 mm q Center Line
72. H630 ECH680 ECH730 ECH749 CH26 CH735 CH745 Hydraulic Lifter to Crankcase Running Clearance 0 011 0 048 mm 0 0004 0 0019 in 0 0241 0 0501 mm 0 0009 0 0020 in Intake Valve Stem to Valve Guide Running Clearance 0 040 0 078 mm 0 0016 0 0031 in 0 038 0 076 mm 0 0015 0 0030 in Exhaust Valve Stem to Valve Guide Running Clearance 0 052 0 090 mm 0 0020 0 0035 in 0 050 0 088 mm 0 0020 0 0035 in Ignition Module Air Gap 0 28 0 33 mm 0 011 0 013 in Speed Sensor Air Gap Intake Valve Guide I D New Max Wear Limit 7 040 7 060 mm 0 2772 0 2780 in 7 134 mm 0 2809 in 1 50 0 25 mm 0 059 x 0 010 in 7 038 7 058 mm 0 2771 0 2779 in 7 134 mm 0 2809 in Exhaust Valve Guide l D New Max Wear Limit 7 040 7 060 mm 0 2772 0 2780 in 7 159 mm 0 2819 in 7 038 7 058 mm 0 2771 0 2779 in 7 159 mm 0 2819 in Guide Reamer Size Standard 0 25 mm O S Intake Valve Minimum Lift 7 050 mm 0 2776 in 7 300 mm 0 2874 in 7 048 mm 0 2775 in 7 298 mm 0 2873 in 8 07 mm 0 3177 in Exhaust Valve Minimum Lift 8 07 mm 0 3177 in Nominal Valve Seat Angle 20 45 KohlerEngines com 24 690 01 Rev K Specifications GENERAL TORQUE VALUES English Fastener Torque Recommendations for Standar
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74. IL e Intake air temperature sensor FUEL RECOMMENDATIONS Refer to Maintenance FUEL LINE Low permeation fuel line must be installed on all Kohler 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
75. Ib Illustrated instructions are provided in service rod 1 Make sure seal bore of crankcase is clean and free of any nicks or burrs 2 Apply a light coat of clean engine oil to outside package diameter of oil seal 5 Repeat above procedure for other connecting rod 3 Drive oil seal into crankcase using a seal driver and piston assembly Make sure oil seal is installed straight and true in bore to depth shown Install Governor Cross Shaft 1 Lubricate governor cross shaft bearing surfaces in Install Crankshaft crankcase with engine oil 1 Lubricate crankshaft journals and connecting rod 2 Slide small lower washer onto A A governor cross shaft bearing SES with engine oil and install cross shaft from inside of crankcase 2 Carefully slide flywheel end of crankshaft through 3 Install nylon washer onto governor cross shaft then main bearing in crankcase start push on retaining ring Hold cross shaft up in position place a 0 50 mm 0 020 in feeler gauge on Install Connecting Rods with Pistons and Rings top of nylon washer and push retaining ring down Piston Detail shaft to secure Remove feeler gauge which will have established proper end play Install Camshaft 1 Liberally apply camshaft lubricant see Tools and Aids to each cam lobe Lubricate camshaft bearing surfaces of crankcase and camshaft with engine oil 2 Position timing mark of crankshaft gear at 12 o
76. JOJJIJUUOJ euluuJo9 G S dung jen d apeg D esn VOE d JojejnDes 1eynoes O JO e S N yoelg W Kai 1 SHUM M UPL r xuld I ejdung H ang eq 9 u 19 eq E used jur 3 MOIS 0 PUM P YH 9 yoela pdd 9 pad Y v oe o Oe eee REI bet T wi O04 609 m e SS LA 9 A E e 10sues eunje1eduue JE JYEJU pue 1osues GYIN a1g16d os yjim seuiBuo yajims Ady jeuondo pue JojJauuo9 euruuo G webeg BuulM 142 37 KohlerEngines com 24 690 01 Rev K EFI SYSTEM ECH J0128uu02 onsouBeiq IV 5 eea IO HY JOSU S dYNL cy T Bee JUL JV Josueg ueB xQo EK aed 2 Side jj ON Z 100 uoniuf ov L lO uoniuf av ZH 10 99fu on vv L Joyoalu jen 3 Z JOJIJUUOJ Aale A J0 99UUO Yyoe g X esnJ YO M jeuondo TW A U9IIMS 9JnSsS9Jg IO n JOJON J91J61S 1 JOJOBUUOND euluuJo9 9 S dung jen d apeg D esnJ VOC d JoyeinBay saynooy 6 101815 N yoeld IN Kai 1 SHUM M uel f Auld l ejdung H anid eq 9 u98Jc yeq d u 19 4p 3 MOJISA a eyuAMpesd 3 45Ee g pes g pad Y 9 9 E L Ge amp o 09 Y 09 Y ES amp og 9 eo eo
77. L 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 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 Check air cleaner cover and base for damage or indications of improper fit and seal 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 Check carburetor throat for dirt Dirt in throat is further indication that air cleaner was not functioning properly Check if oil level is within operating range on dipstick If itis above sniff for gasoline odor 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 slud
78. M measure AC voltage across stator leads using an AC voltmeter Condition Conclusion Voltage is 28 volts or Stator 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 24 690 01 Rev K Condition Conclusion Resistance is 0 064 0 2 ohms Stator is OK Resistance is 0 ohms Resistance is infinity ohms Stator is shorted replace Stator is open replace 4 With engine stopped measure resistance from each stator lead to ground using an ohmmeter Condition Conclusion Resistance is infinity ohms no continuity Stator is OK not shorted to ground Resistance or continuity measured Stator leads are shorted to ground replace 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 less Charging system is OK Battery is unable to hold charge service or replace Voltage is more than 14 7 volts Faulty rectifier regulator replace KohlerEngines com 97 Electrical System FUSES This engine has 3 blade type automotive fuses Replacement
79. N Meter should indicate continuity ground circuit is completed for 1 to 3 seconds Turn key switch back off EFI SYSTEM BOSCH 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 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 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 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 KohlerEngines com 67 EFI SYSTEM BOSCH Fuel Injector Details A Filter Strainer In B Electrical Fuel Supply Connection C Solenoid Winding D Valve Housing E Armature F Valve Body G H Multi Orifice Director Valve Needle Plate With Calibrated Op
80. N m 60 in Ib Make sure that governor arm has not twisted up or down after nut has been tightened 4 Verify that governor has been set correctly With linkage still retained in FULL 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 5 Reconnect dampening spring into its governor lever hole from bottom Reinstall bushing and reattach throttle linkage Reattach governor spring in marked hole 6 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 TROUBLESHOOTING Troubleshooting Guide Condition Possible Cause Fuel pump not running Faulty spark plugs Old stale fuel Incorrect fuel pressure Engine Starts Hard Speed sensor loose or faulty or Fails to Start TPS offset incorrect initialization When Cold Engine temperature sensor faulty Engine temp sensor faulty Faulty coils Low system voltage Faulty injectors 72 KohlerEngines com 24 690 01 Rev K EFI SYSTEM BOSCH Faulty spark plugs Fuel pump not running Fuel pressure low Insufficient fuel delivery Engine starts hard or fails to start TPS offset incorrect Initialization when hot Speed sensor loose or faulty TPS fa
81. OTE 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 a Push on cap reinsert dipstick into tube press completely down or b Threaded cap reinsert dipstick into tube rest cap on tube do not thread cap onto tube 2 Remove dipstick check oil level Level should be at top of indicator on dipstick If oil is low on indicator add oil up to top of indicator mark 4 Reinstall and secure dipstick e 92 KohlerEngines com 24 690 01 Rev K CHANGE OIL AND FILTER Change oil while engine is warm 1 Clean area around oil fill cap dipstick and drain plug 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 10 ft Ib 13 6 N m 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 7 Reinstall oil fill cap dipstick and
82. PS TPS is a sealed non serviceable assembly If diagnosis indicates a bad sensor complete replacement is necessary Magnet that sensor detects is separate and can be replaced or reused If a blink code indicates a problem with TPS it can be tested as follows Diagnostics of sensor ECU will still have electrical faults captured in fault codes P0122 amp P0123 These electrical faults still have same meaning as with prior sensor P0122 detecting low voltage open circuit and P0123 for high voltage conditions between ECU wire harness and sensor Tip when working with any electrical connection remember to keep connections clean amp dry This is best accomplished by cleaning connection thoroughly prior to disassembly Contaminated sensor connections can cause premature engine faults Functionally testing sensor can no longer be done with simple resistance checks If either of these two faults is present or a TPS fault is suspected recommended diagnostic test is as follows If a computer with diagnostic software is available Observe throttle percent and raw TPS values through diagnostic software With diagnostic software communicating to ECU and key ON engine not running these values can be observed while throttle is moved from closed to full open position There should be a smooth and repeatable throttle percent value starting at closed position reading between 0 about 6 5 to WOT position reading 93 100 If one of these va
83. Pin 4Pi weil Blink P Code Ap MA 1 7 MSE 1 0 1 1 I ode plicable to Connection or Failure Description Metal Plastic Plastic Note 32 Pin MSE Cased Cased Caced 1 1 ECU Sys ECU ECU Sys ECU tem Only System tem System 56 P1231 Pump Relay Open Circuit N A N A Y 56 P1232 Pump Relay Short Circuit to G N A N A Y 56 P1233 Pump Relay Short Circuit to B N A N A Y 61 End of Code Transmission Y Y Y NOTE 1 Idle Switch not used 2 Diagnostic of TPS Signal Implausible is disabled in code 3 O2 Sensor Short to Battery diagnostic detection is disabled with SAS fuel cutoff calibrated out 4 Air Temperature Sensor not used 5 Temperature Sensor Signal Implausible diagnostic detection is calibrated out with TPLAUS set to 50 C 6 System too Lean used to be O2 Sensor Short to Ground P0131 7 System too Rich used to be O2 Sensor Control at Lower Limit P0019 8 Obtainable only with ECU 24 584 28 S or later 9 Will not blink out Code 21 Component Engine Speed Sensor Engine Wiring Harness Related Fault ECU receiving inconsistent tooth count 24 Pin MSE 1 0 Plastic Cased ECU signals from speed sensor e Pin circuits 9 and or 10 wiring or Condition Possible misfire as ECU attempts to connectors resynchronize during which time fuel and e Shielding for pin circuits 9 and or 10 spark calculations are not made Sa a or not poe EE Conclusion Engine Speed Sensor Related ab erc ee e Sensor connector or wiring e Sensor
84. acking plate 132 KohlerEngines com N fy 4 gd A Metal Debris Screen B Fan C Flywheel D Spacer E Hex Bolt 1 Verify locating tabs on back of fan are inserted into locating holes on flywheel 24 690 01 Rev K 2 To assist assembly find 4 intake manifold studs with M6 thread at least 100 mm in length to be used as guide pins Insert intake manifold studs through cooling fan mounting holes and thread them 4 or 5 turns into flywheel 3 Install a spring washer on each stud with concave side down toward cooling fan 4 Install a spacer on each stud with stepped end down Smaller diameter should extend through spring washer and fan so tip is resting on flywheel and shoulder is resting on spring washer 5 Install support ring on studs so it is resting on spacers Then install metal screen on top of support ring 6 Install plain washers on each hex cap screw Apply Loctite 242 to hex cap screw threads 7 Carefully remove 2 studs and replace with 2 screws Torque screws to 9 9 N m 88 in Ib Repeat procedure for other 2 studs and screws Install Plastic Debris Screen Place plastic grass screen on fan and secure with hex screws Torque screws to 4 0 N m 35 in Ib Install Electric Starter Motor and ECU Bracket ECH EFI 1 Install electric starter motor using screws Position ECU bracket as shown 2 Torque screws
85. all and assemble stop collar retainer assembly a Install stop collar down onto armature shaft with counter bore recess up 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 pivot 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
86. alling coarse stones in hone proceed as follows 120 KohlerEngines com 1 Lower hone into bore and after centering adjust so 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 them with burnishing stones Continue with burnishing stones until bore is within 0 013 mm 0 0005 in of desired size and then use finish stones 220 280 grit and polish bore to its 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 and 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 These measurements should be taken at 3 locations in cylinder at top middle and bottom Two measurements should be taken perpendicular to each other at each location Clean Cylinder Bore After Honing Proper cleaning of cylinder walls following boring and or honing is very critical to a successful overhaul Machining gr
87. 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 ignited and burned 60 KohlerEngines com 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 tempe
88. 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 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
89. 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 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 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 voltage 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 With sensor still hot minimum of 400 C 752 F switch meter to Rx1K or Rx2K scale and check resis
90. arb of lift fuel pump and secured with a spring clamp NOTE Ensure all parts are clean undamaged and free of debris and make sure electrical connector has seal in place NOTE Fuel pump module pins should be coated with a thin layer of electric grease to prevent fretting and corrosion and may need to be reapplied if fuel pump module is being reused 134 KohlerEngines com 24 690 01 Rev K Reassembly 1 Install lift fuel pump pulse or mechanical and lines as an assembly Connect pulse line to crankcase vacuum fitting if engine has a pulse lift fuel pump 2 Install lift fuel pump to bracket on housing using screws Torque to M6 screws to 7 3 N m 68 in Ib into new holes or 6 2 N m 55 in Ib into used holes 3 Connect in line 10 micron EFI fuel filter and hose to inlet barb of lift fuel pump and secure with spring clamp 4 Install fuel pump module baffle to crankcase using screws Torque screws to 11 9 N m 105 in Ib 5 Push high pressure fuel line connector onto fuel pump module fitting 6 If Oetiker clamp was cut to remove inlet fuel line slide a new Oetiker clamp onto fuel line and connect fuel line Only use an Oetiker clamp pliers to crimp Oetiker clamps Oetiker clamp crimp must point up away from top of fuel pump module and abrasion sleeve must be positioned over Oetiker clamp 7 Connect electrical connector to top of fuel pump module Ensure grey locking tab is pulled out before connecting Push conn
91. ase Screw 8 3 N m 73 in Ib Crankshaft Position Sensor Later Design Bracket Crankshaft Position Sensor to Bracket Screw 6 8 N m 60 in Ib Crankshaft Position Sensor Bracket to Crankcase Screw 7 3 N m 65 in Ib Intake Manifold Fastener torque in 2 increments first to 7 8 N m 69 in Ib finally to 10 5 N m 93 in Ib first to 7 4 N m 66 in Ib finally to 9 9 N m 88 in Ib Manifold Absolute Pressure MAP Sensor Fastener Engines with Separate MAP and Intake Air Temperature Sensors 7 3 N m 65 in Ib Temperature Manifold Absolute 7 3 N m 65 in Ib Pressure TMAP Sensor Fastener Engines with Combined Sensor Air Cleaner to Throttle Body Fastener 8 2 N m 73 in Ib Nut Heavy Duty Air Cleaner Mounting 5 8 N m 51 in Ib Bracket Fastener Fuel Injector Cap Fastener 7 3 N m 65 in Ib Muffler Retaining Nut 27 8 N m 246 in Ib 24 4 N m 216 in Ib Oxygen Sensor 50 1 N m 37 ft Ib Oil Cooler Oil Cooler Adapter Nipple 28 5 N m 21 ft Ib 27 N m 20 ft Ib Fastener Into Blower Housing Between Oil Cooler Hoses Speed Control Bracket 2 8 N m 25 in Ib 2 3 N m 20 in Ib Fastener Assembled to Cylinder Heads 10 7 N m 95 in Ib into new holes N m 65 in lb into used holes Fastener Assembled to Blower Housing 7 3 2 8 N m 25 in Ib into new holes 2
92. ases contain poisonous carbon monoxide Carbon monoxide is odorless colorless and can cause death if inhaled Keep hands feet hair and clothing away from all moving parts to prevent injury Never operate engine with covers shrouds or guards removed 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 1 Insert rubber stopper into oil fill hole Be sure pinch clamp is installed on hose and use tapered adapters to connect hose between stopper and one manometer tube Leave other tube open to atmosphere Check that water level in manometer is at 0 line Make sure pinch clamp is closed 2 Start engine and run no load high speed 3 Open clamp and note water level in tube Level in engine side should be a minimum of 10 2 cm 4 in above level in open side If level in engine side is less than specified low no vacuum or level in engine side is lower than level in open side pressure check for conditions in table below 4 Close pinch clamp before stopping engine Condition To test crankcase vacuum with vacuum pressure gauge 1 Remove dipstick or oil fill p
93. attery 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 before 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 24 690 01 Rev K 2 For plastic cased ECU s below 24 584 28 85 system can be primed by manually cycling fuel pump 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
94. ave leads connected to pin terminals as described in step 3 Rotate throttle shaft slowly 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 4600 5200 Q without a stop pin or 3200 4100 Q with a stop pin Disconnect main wiring harness connector from TPS leaving TPS assembled to throttle body Refer to Resistance Table and perform resistance checks indicated between terminals in TPS switch with throttle in positions specified 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 Input pin is 12 and ground is pin 10 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 40 KohlerEngines com 24 690 01 Rev K 7 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 Reconnect Black and TPS connector plugs b Perform TPS Learn Procedure integrating new sensor to ECU Contactless Magnet Type T
95. ax Out of Round Limit Closure Plate End Main Bearing Journal O D New O D Max Wear Limit Max Taper Limit Max Out of Round Limit Connecting Rod Journal O D New O D Max Wear Limit Max Taper Limit Max Out of Round Limit Crankshaft T I R PTO End Crank in Engine Entire Crank in V Blocks 40 913 40 935 mm 1 6107 1 6116 in 40 843 mm 1 608 in 0 022 mm 0 0009 in 0 025 mm 0 0010 in 40 913 40 935 mm 1 6107 1 6116 in 40 843 mm 1 608 in 0 022 mm 0 0009 in 0 025 mm 0 0010 in 35 950 35 973 mm 1 4153 1 4163 in 35 941 mm 1 415 in 0 018 mm 0 0007 in 0 025 mm 0 0010 in 0 279 mm 0 0110 in 0 10 mm 0 0039 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 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 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 0 279 mm 0 0110 in 0 10 mm 0 0039 in Values are in Metric units Values in parentheses are English equivalents 24 690 01 Rev K KohlerEngines com 17 Specifications CLEARANCE SPECIFICATIONS Cylinder Bore ECH630 ECH680 ECH730 ECH749 CH26 CH735 CH745 Bore I D New O D Max Wear Limit Max Out of Round Limit 80 000 80 025 mm 3 1496 3 2689 in 80 075 mm 3 1526 in 0 120 mm 0 0047 in
96. ca minimum 10 F 23 C or below 400 cca minimum 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 24 690 01 Rev K KohlerEngines com 95 Electrical System 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 20 or 25 amp regulated charging system 20 25 Amp Regulated Charging System IC A Battery B Starter Fuse D Rectifier Regulator Flywheel Stator E Connector Block 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 termi
97. ciently 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 components 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 i
98. clock position 3 Turn governor cross shaft clockwise until lower end of shaft contacts cylinder Make sure cross shaft remains in this position while installing camshaft 4 Slide camshaft into bearing surface of crankcase positioning timing mark of camshaft gear at 6 o clock position Make sure camshaft gear and crankshaft A Cylinder 1 B Cylinder 2 gear mesh with both timing marks aligned NOTE Oylinders are numbered on crankcase Make Oil Pump Assembly sure to install piston connecting rod and end cap into its appropriate cylinder bore as Oil pump is mounted inside closure plate If service was previously marked at disassembly Do not mix required and oil pump was removed refer to assembly end caps and connecting rods procedures under Oil Pump Assembly in Disassembly Inspection and Service 24 690 01 Rev K KohlerEngines com 123 Reassembly Governor Gear Assembly Governor gear assembly is located inside closure plate If service was reguired and governor was removed refer to assembly procedures under Governor Gear Assembly in Disassembly Inspection and Service Thrust Bearing Washer and Shim Kn n A Thrust Shim B Thrust Washer Needle Thrust A C Bearing D Bearing Race E Closure Plate Some specifications use a needle type thrust bearing thrust washer and shim spacer to control end play of crankshaft If these items are noted duri
99. coating of Kohler lubricant see Tools and Aids to base of each new lifter before it is installed 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 Cut a 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 2 or 3 times to force oil out of feed hole in side of lifter Disassemble Cylinder Heads NOTE These engines use valve stem seals on intake and exhaust valves Use a new seal whenever valve is removed or if seal is deteriorated or damaged in any way Never reuse an old seal 1 Remove screws rocker arm pivots and rocker arms from cylinder head 2 Compress valve springs using a valve spring compressor 3 Once valve spring is compressed remove valve spring keepers then remove following items e Valve spring retainers e Valve springs e Valve spring caps e Intake and exhaust valve mark position e Valve stem and seals intake and exhaust 4 Repeat above procedure for other cylinder head Do not interchange parts from 1 cylinder head to other 24 690 01 Rev K KohlerEngines com 111 Disassembly Inspection and Service Inspection and Service Valve Details EKHAUST EKHAUST VALV
100. connections that intermittently ground ignition kill circuit e Quality of fuel dirt water stale mixture e Spark plug lead s disconnected e Spark plug lead boot loose on plug e Spark plug lead loose Engine Will Not Idle e Faulty carburetor e Faulty cylinder head gasket e Faulty or misadjusted choke or throttle controls e Fuel pump malfunction vacuum hose clogged or leaking e ntake 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 Engine overheated e Faulty spark plug s e Idle fuel adjusting needle s improperly set e dle speed adjusting screw improperly set e Inadequate fuel supply e Low compression e Quality of fuel dirt water stale mixture e Restricted fuel tank cap vent Engine Overheats 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 e 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 24 690 01 Rev K e Cooling fan broken e Excessive engine load e Fan belt failed off
101. d 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 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 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 center compression ring end gap clearance is 0 25 0 56 mm 0 010 0 022 in with maximum wear limit of 0 94 mm 0 037 in 5 After installing new compression top and middle rings on piston check side clearance If side clearance is greater than specified a new piston must be used Model ECH630 749 engines Top compression ring to groove side clearance is 0 050 0 095 mm 0 0019 0 0037 in Middle compression ring to roove side clearance is 0 030 0 075 mm 0 0012 0 00307 in Model CH26 CH735 CH745 engines Top compression ring to groove side clearance is 0 025 0 048 mm 0 0010 0 0019 in Middle compression ring to groove side clearance is 0 015 0 037 mm 0 0006 0 0015 in Piston Style B 1 Oylinder bore mu
102. d Applications Bolts Screws Nuts and Fasteners Assembled Into Cast Iron or Steel Grade 2 or 5 Fasteners Into Aluminum Size Grade 2 Grade 5 Grade 8 Q Tightening Torque N m in Ib 20 8 32 2 3 20 2 8 25 2 3 20 10 24 3 6 32 4 5 40 3 6 32 10 32 3 6 32 4 5 40 1 4 20 7 9 70 13 0 115 18 7 165 7 9 70 1 4 28 9 6 85 15 8 140 22 6 200 5 16 18 17 0 150 28 3 250 39 6 350 17 0 150 5 16 24 18 7 165 30 5 270 3 8 16 29 4 260 3 8 24 33 9 300 Tightening Torque N m ft Ib 20 5 16 24 40 7 30 3 8 16 47 5 35 67 8 50 3 8 24 54 2 40 81 4 60 71 16 14 47 5 35 74 6 55 108 5 80 7 16 20 61 0 45 101 7 75 142 5 105 1 2 13 67 8 50 108 5 80 155 9 115 1 2 20 94 9 70 142 4 105 223 7 165 9 16 12 101 7 75 169 5 125 237 3 175 9 16 18 135 6 100 223 7 165 311 9 230 5 8 11 149 5 110 244 1 180 352 6 260 5 8 18 189 8 140 311 9 230 447 5 330 3 4 10 199 3 147 332 2 245 474 6 350 3 4 16 271 2 200 440 7 325 637 3 470 Metric Fastener Torque Recommendations for Standard Applications Property Class Noncritical Size ines ei Tightening Torque N m in Ib 10 M4 1 2 11 1 7 15 2 9 26 4 1 36 5 0 44 2 0 18 M5 2 5 22 3 2 28 5 8 51 8 1 72 9 7 86 4 0 35 M6 4 3 38 5 7 50 9 9 88 14 0 124 16 5 146 6 8 60 M8 10 5
103. d position of short screws for reassembly Coil and any hoses may remain attached to baffle after being unplugged or disconnected 5 Remove outer baffles 6 Remove remaining screws securing blower housing Remove blower housing Remove Oil Sentry NOTE This is optional Removing Oil Sentry is not required to remove breather cover 1 Disconnect lead from Oil Sentry switch 2 Remove Oil Sentry switch from breather cover Remove Oil Temperature Sensor NOTE Unless oil temperature sensor is damaged or malfunctioning disassembly from breather cover is unnecessary 1 Disconnect lead from oil temperature sensor 2 Remove oil temperature sensor from breather cover 3 Remove breather hose from breather cover 24 690 01 Rev K Remove Inner Baffles and Breather Cover Disassembly Inspection and Service 1 Remove screws securing inner baffles to crankcase 2 Remove inner valley baffles 3 Remove remaining screws from breather cover 4 Pry under protruding edge of breather cover with a screwdriver to break gasket seal Do not pry on sealing surfaces as it could cause damage resulting in leaks 5 Remove breather cover and gasket Intake Manifold Components ECH EFI A unb Ao B Fuel Injector C Fuel Rail D Metal Retaining Clip Crankshaft Position Crankshaft Position E Intake Manifold F Sensor Earlier G Sensor Later Design Bracket Design Bracket Remove Cranksha
104. d 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 Incorporated 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 62 KohlerEngines com 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
105. de 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 30 KohlerEngines com A lift fuel pump is used to move fuel from tank through an in line fuel filter and fuel line Fuel is then pumped to fuel pump module Fuel pump module regulates fuel pressure to a system operating pressure of 39 psi Fuel is delivered from fuel pump module through high pressure fuel line into injectors which inject fuel into intake ports ECU controls amount of fuel by varying length of time that injectors are on This can range from 2 to over 12 milliseconds depending on fuel requirements Controlled injection of fuel occurs every other crankshaft revolution or once for each 4 stroke cycle When intake valve opens air fuel mixture is drawn into combustion chamber compressed ignited and burned 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
106. der Leakdown Tester Individual component available Adapter 12 mm x 14 mm Required for leakdown test on XT 6 engines For checking combustion retention and if cylinder piston rings or valves are worn Kohler 25 761 05 S Design Technology Inc DTI 731 03 Dealer Tool Kit Domestic Complete kit of Kohler required tools Components of 25 761 39 S Ignition System Tester Cylinder Leakdown Tester Oil Pressure Test Kit Rectifier Regulator Tester 120 V AC 60Hz Kohler 25 761 39 S Kohler 25 455 01 S Kohler 25 761 05 S Kohler 25 761 06 S Kohler 25 761 20 S Dealer Tool Kit International Complete kit of Kohler required tools Components of 25 761 42 S Ignition System Tester Cylinder Leakdown Tester Oil Pressure Test Kit Rectifier Regulator Tester 240 V AC 50Hz Kohler 25 761 42 S Kohler 25 455 01 S Kohler 25 761 05 S Kohler 25 761 06 S Kohler 25 761 41 S 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 For Laptop or Desktop PC Kohler 25 761 23 S EFI Service Kit For troubleshooting and setting up an EFI engine Components of 24 761 01 S Fuel Pressure Tester Noid Light 90 Adapter In line T Fitting Code Plug Red Wire Code Plug Blue Wire Shrader Valve Adapter Hose Kohler 24 761 01 S
107. e as a cleaning agent A WARNING Accidental Starts can cause severe injury or death Disconnect and ground S spark plug lead s before x servicing CR A CAUTION X Electrical Shock can cause injury Ss Do not touch wires while engine is running Before working on engine or equipment disable engine as follows 1 Disconnect spark plug lead s 2 Disconnect negative battery cable from battery A WARNING Ro Rotating Parts can cause CR severe injury Stay away while engine is in operation clothing away from all moving parts to prevent injury Never operate engine with covers shrouds or guards removed A WARNING A CAUTION Damaging Crankshaft and Flywheel can cause Jo personal injury QN Hot Parts can cause severe burns ti Gi nas Do not touch engine while operating or just after stopping 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 Keep hands feet hair and Never operate engine with heat shields or guards removed A WARNING Carbon Monoxide can cause severe nausea fainting or death Avoid inhaling exhaust fumes A WARNING Cleaning Solvents can Wi cause severe injury or death Use only in well ventilated areas away from ignition sources
108. e Faulty carburetor e High crankcase oil level e Lean fuel mixture e Low cooling system fluid level e Low crankcase oil level e Radiator and or cooling system components clogged restricted or leaking e Water pump belt failed broken e Water pump malfunction Engine Knocks e Excessive engine load e Hydraulic lifter malfunction e Incorrect oil viscosity type e Internal wear or damage e Low crankcase oil level e Quality of fuel dirt water stale mixture KohlerEngines com 25 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 Crankcase 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 e Clogged broken or inoperative crankcase breather e Loose or improperly torqued fasteners e Piston blow by or leaky valves e Restricted exhaust 26 KohlerEngines com EXTERNA
109. e Lean condition check oxygen sensor e Throttle shaft inside TPS worn broken signal with VOA and see Oxygen or damaged Sensor e Throttle plate loose or misaligned e Throttle plate bent or damaged Engine wiring harness related such as a allowing extra airflow past or restricting cut wire broken or pinched movement CH ESSA Code 0132 elate e Circuit providing voltage or ground to Component Oxygen Sensor TPS damaged Fault O28 1 Circuit High Voltage e TPS signal input circuit damaged Condition _ Shorted connection or faulty sensor Conclusion Oxygen Sensor Related Code 0123 e Sensor connector or wiring problem Component Throttle Position Sensor TPS e Sensor contaminated or damaged e e Poor ground path Fault TPS Circuit High Voltage e Pin circuit wiring or connectors Condition Shorted connection or faulty sensor ECU Black pin 10 or Black pin 17 Conclusion TPS Sensor Related Sp e Sensor connector or wiring Engine Wiring Harness Related e Sensor output affected or disrupted by e Difference in voltage between sensed dirt grease oil wear voltage and actual sensor voltage e Sensor loose on throttle body manifold e Short in wire harness Throttle Body Related e Throttle shaft or bearings worn damaged Engine Wiring Harness Related e ECU pins Black 10 12 and 16 damaged wiring connectors e ECU pins Black 10 12 and 16 routed near noisy electrical signal coils alternator e Intermi
110. e an electronic meter such as a digital voltmeter Simple mechanical meters may place a heavy electrical load on sensor and cause inaccurate readings Since resistance of sensor is highest at low temperatures such meters will cause largest inaccuracies when sensor is in a cool exhaust Visual Inspection 1 Lookfor a damaged or disconnected sensor to engine harness connection 2 Look for damage to sensor lead wire or associated engine wiring due to cutting chaffing or melting on a hot surface 3 Disconnect sensor connector and look for corrosion in connector 4 Try reconnecting sensor and observe if problem has cleared 5 Correct any problems found during visual check KohlerEngines com 43 EFI SYSTEM ECH Sensor Signal Observation NOTE Do not cut into or pierce sensor or engine 44 wiring to make this connection Sensor produces a very small signal Corrosion or damage to wiring could lead to an incorrect signal because of repairs or contamination to sensor Using a voltmeter observe voltage between Pin C and Pin D before engine is started With key ON and sensor unplugged voltage should read about 5 0 volts With sensor attached using diagnostic software voltage should read about 1 0 volt This voltage is generated by ECU If it is not present there is a short in associated wiring and corrective action should be taken If voltage still is not present there is a problem with ECU or engine harness Reconn
111. e and secure with screws Torque screws as follows a Install fastener into location 1 and lightly tighten to position pump b Install fastener into location 2 and fully torque to recommended value c Torque fastener in location 1 to recommended value First Time Installation 10 7 N m 95 in Ib All Reinstallations 6 7 N m 60 in Ib 4 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 24 690 01 Rev K 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 damaged 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 t
112. e fires and severe containers in well ventilated unoccupied buildings away Mme from sparks or flames Spilled fuel could ignite if it comes 4 ge Ls A 4 Do not fill fuel tank while engine is hot or in contact with hot parts or sparks from ignition Never use O N s A running gasoline as a cleaning agent Fuel Pump Remove Lift Fuel Pump and Fuel Pump Module NG Ss Pulse Pump B Inlet Hose Electrical Connector F Fuel Pump Module Outlet to Fuel Pump Module D Pulse Hose Fuel Pump Module H High Pressure Fuel Baffle Line Connector J Purge Port Vent Oetiker Clamp Fitting Remove Lift Fuel Pump Pulse Style Pumps 1 2 3 106 Disconnect fuel line at in line fuel filter on tank to pulse pump line Disconnect pulse vacuum line from crankcase Remove screws securing fuel pump to bracket on blower housing Note or mark orientation of fuel pump then remove fuel pump with lines attached KohlerEngines com Mechanical Style Pumps Mechanical style fuel pump is part of valve cover assembly 1 2 Disconnect fuel lines at pump outlet and in line fuel filter Fuel pump will be removed with valve cover Refer to valve cover removal procedure 24 690 01 Rev K Remove Fuel Pump Module ECH EFI Disassembly Inspection and Service Remove Throttle Body ECH EFI 1 Remove screws securing fuel pump module 2 Remove inlet fuel line from fuel pump
113. e 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 Fault Condition Denotes end of fault codes If signaled first no other fault codes are present Conclusion Troubleshooting Flow Chart 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 within system Flow Chart Diagnostic Aids Diagnostic Aid 1 system power MIL does not illuminate when key is turned ON NOTE MIL in Metal Cased ECU systems is an LED MIL in Plastic Cased ECU systems must be a 1 4 watt incandescent lamp Possible causes e Battery e Main system fuse e MIL light bulb burned out o MIL electrical circuit problem 35 Pin MA 1 7 Metal Cased ECU Pin circuits 31 and 31A 24 Pin MSE 1 0 Plastic Cased ECU Pin circuits 19 and 84 24 690 01 Rev K EFI SYSTEM BOSCH 32 Pin MSE 1 1 Plastic Cased ECU Pin circuits 29 and 84 e ignition switch e Permanent ECU power circuit problem 35 Pin MA 1 7 Metal Cased ECU Pin circuit 16 24 Pin MSE 1 0 Plastic Cased ECU Pin circuit 1 32 Pin MSE 1 1 Plastic Cased ECU Pin circuit 1
114. e must be relieved through test valve in fuel rail prior to servicing or removing any fuel system components Do not smoke or work near heaters or other fire hazards Have a fire extinguisher handy and work only in a well ventilated area Function of fuel system is to provide sufficient 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 as described earlier under Fuel Pump 80 KohlerEngines com 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 syste
115. e pressure to switch As pressure increases through range of 2 0 5 0 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 2 0 5 0 psi Tester should indicate a change to continuity switch closed down to 0 psi 4 Replace switch if it does not operate as specified Normally Open Switch 1 Connect continuity tester across blade terminal and metal case of switch With O psi pressure applied to Switch tester should indicate no continuity switch open 2 Gradually increase pressure to switch As pressure increases through range of 2 0 5 0 psi tester should indicate a change to continuity switch closed Switch should remain closed as pressure is increased to 90 psi maximum 3 Gradually decrease pressure through range of 2 0 5 0 psi Tester should indicate a change to no continuity switch open down to 0 psi CH Models Pressure Switch PSI 12 099 04 2 6 24 099 03 2 5 25 099 27 2 5 28 099 01 2 6 48 099 07 12 16 52 099 08 7 11 52 099 09 7 11 KohlerEngines com 93 Electrical System SPARK PLUGS Inspection A CAUTION W Electrical Shock can cause injury Do not touch wires while engine is running Spark Plug Component and Details o E o A Wire Gauge B Spark Plug C Ground Electrode D Gap
116. e 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 Fault Long term fuel adaptation control is at upper or lower limit Condition System operates closed loop No appreciable performance loss as long as temporary adaptation can provide sufficient compensation Conclusion Oxygen Sensor Related e Sensor connector or wiring problem e Sensor contaminated or damaged e Exhaust leak e Poor ground path e Pin circuit wiring or connectors Pin 10 for 35 Pin MA 1 7 Metal Cased ECU Pin 11 for 24 Pin MSE 1 0 Plastic Cased ECU Pin 20 for 32 Pin MSE 1 1 Plastic Cased ECU 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 circuit 17 for metal cased ECU pin circuit 2 for plastic cased ECU and actual injector voltage circuit 45 45A e Problem in wiring harness e ECU to harness connection problem Systems Related e Ignition spark plug plug wire ignition coil e Fuel fuel type quality injector fuel pressure fuel pump e Combustion air air cleaner dirty restricted intake leak throttle bores e Base engine problem rings valves
117. ecessary An ohmmeter may be used to test wiring and coil windings NOTE Do not ground primary coil with ignition ON as they may overheat or spark NOTE Always disconnect spark plug lead from spark plug before performing following tests NOTE If ignition coil s are disabled and an ignition fault is registered system will automatically disable corresponding fuel injector drive signal Fault must be corrected to ignition coil and ECU power switch must be turned OFF for 10 seconds for injector signal to return This is a Se measure to prevent bore washing and oil ilution Testing Using an ohmmeter set on Rx1 scale check resistance in circuits as follows 1 To check cylinder coil 1 starter side disconnect Black connector from ECU and test between Black pins 1 and 15 To check cylinder coil 2 oil filter side disconnect Grey connector from ECU and test between Grey pins 10 and 17 Wiring and coil primary circuits are OK if readings are 0 5 0 8 O 2 If reading s are not within specified range check and clean connections and retest 3 Ifreading s are still not within specified range test coils separately from main harness as follows a Remove screw retaining coil to housing and disconnect primary leads connector 24 690 01 Rev K EFI SYSTEM ECH b Connect an ohmmeter set on Rx1 scale to primary terminals of coil Primary resistance should be 0 5 0 8 Q c Connect an ohmmeter set on Rx10K scale between
118. ect sensor and start engine Run engine at sufficient speed to bring sensor up to operating temperature Maintain for 1 to 2 minutes to ensure that engine has gone closed loop Once in closed loop sensor voltage should cycle between about 100 to 250 mv low speed idle and 700 to 900 mv high speed no load If this cycling is not observed a determination must be made if problem is with engine or sensor Check engine harness for battery voltage on heater circuit Removal Inspection NOTE Apply anti seize compound only to threads Anti seize compound will affect sensor performance if it gets into lower shield of sensor 1 If sensor has heavy deposits on lower shield engine oil or fuel may be source 2 f heavy carbon deposits are observed incorrect engine fuel control may be occurring 3 If sensor is at room temperature measure between signal leads black wire Pin C and grey wire Pin D attached to sensor If resistance is less than one megohm sensor has an internal short 4 With sensor at room temperature measure heater circuit resistance purple wire Pin A and white wire Pin B resistance should be 8 1 11 1 O 5 Ifa damaged sensor is found identify root cause which may be elsewhere in application Refer to Troubleshooting Oxygen Sensor O table 6 Aspecial dry to touch anti seize compound is applied to all new oxygen sensors at factory If recommended mounting thread sizes are used this material p
119. ector onto terminal until a click is heard then push in grey locking tab to lock connector 8 Install fuel pump module to baffle with screws Torque screws to 9 2 N m 81 in Ib Install External Governor Control ECH EFI X Speed Control A Bracket B Cable Clamp C Greu D Throttle Actuator Lever bottom E Spring Washer F Throne Ges Lever G Flat Washer H Nut l Return Spring 1 Install governor lever onto governor cross shaft 2 Make sure throttle linkage linkage spring and black linkage bushing are connected to governor lever and to throttle lever on throttle body 24 690 01 Rev K KohlerEngines com 135 Reassembly A WARNING Accidental Starts can cause severe injury or death Disconnect and ground spark plug lead s before servicing xf Neg Before working on engine or equipment disable engine as follows 1 Disconnect spark plug lead s 2 Disconnect negative battery cable from battery External Engine Components Heavy Duty Air Low Profile Air Low Profile Air Cleaner B Cleaner e Cleaner Cover B Element COver E Paper Element F Precleaner G gp e H Dipstick Tube Dipstick J Spark Plug Lead K Oil Drain Plug L O ring M Oil Cooler N Nipple O Oil Filter 136 KohlerEngines com 24 690 01 Rev K Install Throttle Control Panel Reasse
120. ecures in same hole as rectifier regulator fastener torque screw securing to backing plate to 2 8 N m 25 in Ib into new holes or 2 3 N m 20 in Ib into used holes c Ground lead that secures in ground lug hole of rectifier regulator and to backing plate torque Screws to 5 6 N m 50 in Ib into new holes or 4 0 N m 35 in Ib into used holes 3 Connect plug to rectifier regulator If purple wire was removed verify locking tang is raised on terminal and push wire terminal into plug prior to connecting to rectifier regulator Install Metal Debris Screen Spring Washer Details A Ground Strap B Ground Lead C Ground Lug NOTE Rectifier regulator middle terminal B is offset not equally spaced from outer terminals AC Verify rectifier regulator plug is assembled to match terminal offset of rectifier regulator 1 Install rectifier regulator in blower housing if removed previously Reinstall any washers and hose clamps a If engine has ground strap secure it against outer side of rectifier regulator with a silver or green plated screw b If engine has ground lead that secures in same hole as rectifier regulator fastener secure one end to rectifier regulator and other end to backing plate c If engine has ground lead that secures in separate ground lug fastener hole in rectifier regulator secure one end to ground lug and other end to b
121. ed 24 690 01 Rev K KohlerEngines com 55 EFI SYSTEM ECH Code 0336 Code 0352 Component Crankshaft Position Sensor Component Ignition Coil Fault Crankshaft Position Sensor Noisy Signal Fault Cylinder 2 Ignition Coil Malfunction Condition Air gap incorrect loose sensor faulty bad Condition Broken wire in harness may not be battery shorted or faulty connection visible shorted connection or faulty faulty sensor or faulty sensor grounding sensor Conclusion Crankshaft Position Sensor Related Conclusion Engine Wiring Harness Related e Sensor connector or wiring e Connection to ignition or fuse e Sensor loose or air gap incorrect e Pin circuit wiring or connectors ECU pin Grey 10 Crankshaft Position Sensor Wheel e ECU to harness connection problem Related e Damaged teeth Ignition System Related e Gap section not registering e Incorrect spark plug s used e Poor connection to spark plug Engine Wiring Harness Related e Pin circuit wiring or connectors ECU pin Black 4 and Black 13 pode Use2 e ECU to harness connection problem Component System Voltage Fault System Volt L Ignition System Related Sen Gg 7 age WE badi e Non resistor spark plug s used iina G age ds SIDE Ban TUse vr e Faulty or disconnected ignition coil or SE secondary lead Conclusion Corroded
122. ee Cylinder Head N ne a Valve P Dowel Pin Remove Valve Covers ECH EFI 1 2 Remove screws securing each valve cover Note valve cover differences for proper location in reassembly Ensure any brackets removed are reassembled in same location Covers should lift off without prying Remove Spark Plugs Remove spark plug from each cylinder head Remove Cylinder Heads and Hydraulic Lifters NOTE Cylinder heads are retained using either screws 110 or nuts and washers on studs Do not interchange or mix components KohlerEngines com Remove screws or nuts and washers securing each cylinder head Discard screws or nuts and washers once removed Do not reuse Studs if present should only be removed if damaged or if cylinder reconditioning is necessary Once removed they must be replaced Mark location of push rods as either intake or exhaust and cylinder 1 or 2 Push rods should always be reinstalled in same positions Carefully remove push rods cylinder heads and head gaskets Remove lifters from lifter bores Use a hydraulic lifter tool Do not use a magnet to remove lifters Mark lifters by location as either intake or exhaust and cylinder 1 or 2 Hydraulic lifters should always be reinstalled in same position 24 690 01 Rev K Disassembly Inspection and Service Inspection Check base surface of hydraulic lifters for wear or damage If lifters need to be replaced apply a liberal
123. eel NOTE Always use a flywheel strap wrench or holding tool to hold flywheel when loosening or tightening flywheel screw Do not use any type of bar or wedge to hold flywheel Use of such tools could cause flywheel to become cracked or damaged NOTE Always use a flywheel puller to remove flywheel from crankshaft Do not strike crankshaft or flywheel as these parts could become cracked or damaged Striking puller or crankshaft can cause crank gear to move affecting crankshaft endplay 24 690 01 Rev K KohlerEngines com 113 Disassembly Inspection and Service 1 Remove shoulder bolts securing fan if still attached and remove fan 2 Use a flywheel strap wrench or holding tool see Tools and Aids to hold flywheel and loosen screw securing flywheel to crankshaft 3 Remove screw and washer 4 Use a puller to remove flywheel from crankshaft 5 Remove woodruff key Inspection Inspect flywheel for cracks and flywheel keyway for damage Replace flywheel if it is cracked Replace flywheel crankshaft and key if flywheel key is sheared or keyway is damaged Inspect ring gear for cracks or damage Kohler does not provide ring gear as a serviceable part Replace flywheel if ring gear is damaged Remove Stator and Backing Plate ECH EFI 1 Remove screws securing backing plate Remove backing plate 2 Remove screws and stator Note position routing of stator lead Remove Closure Plate Assembly 1 Remove screws secu
124. emperature IAT or TMAP Engine Wiring Harness Related Fault Intake Air Temperature IAT or TMAP ob DE e RES Sensor Circuit Low Voltage e ECU to harness connection problem or Condition Shorted connection faulty sensor or broken wire shorted wire Conclusion Temperature IAT or TMAP Sensor System Related Related e Engine is operating above 176 C e Sensor wiring or connection 350 F temperature sensor limit Engine Wiring Harness Related e Pin circuits Black 10 and Black 8 may be damaged or routed near noisy signal coils alternator etc e ECU to harness connection problem 52 KohlerEngines com 24 690 01 Rev K EFI SYSTEM ECH Code 0122 Code 0131 Component Throttle Position Sensor TPS Component Oxygen Sensor Fault TPS Circuit Low Voltage or Open Fault O2S 1 Circuit Low Voltage Condition Open connection broken wire or faulty Condition Open connection broken wire or faulty sensor sensor Conclusion TPS Related Conclusion Oxygen Sensor Related e TPS bad or worn internally e Sensor connector or wiring problem e Sensor contaminated corroded or Engine Wiring Harness Related damaged e Broken or shorted wire in harness e Poor ground path ECU Black pin 10 to TPS pin 1 e Pin circuit wiring or connectors ECU Black pin 12 to TPS pin 3 ECU Black pin 10 or 17 ECU Black pin 16 to TPS pin 2 TPS Learn Procedure Incorrect Throttle Body Related
125. ening 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 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 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 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 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 see Tools and Aids into one connector 68 KohlerEngines com 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
126. ensor resistance separately across pin Resistance value should again be 1850 2450 O a If resistance is out of specifications check local temperature Sensor resistance will go down as temperature is higher Replace TMAP sensor if determined to be faulty b If itis within specifications proceed to Step 6 24 690 01 Rev K 6 Check circuits input ground from main harness connector to sensor plug for continuity damage etc Connect one ohmmeter lead to Black pin 8 in main harness connector as in step 4 Connect other lead to terminal 3 in sensor plug Continuity should be indicated Repeat test between Black pin 10 and terminal 4 in sensor plug T Reinstall sensor If a blink code indicates a problem with Manifold Absolute Pressure TMAP Sensor Circuit P0107 or P0108 it can be tested as follows 1 Make sure all connections are making proper contact and are free of dirt and debris Slide locking tab out and pull off TMAP connector Turn key switch to ON and check with a volt meter by contacting red lead to pin 1 and black lead to pin 2 There should be 5 volts present indicating ECU and wiring harness are functioning 2 Check continuity in wire harness Ohms between Pin 3 at sensor connector and Black pin 11 connector at ECU should be near zero ohms If no continuity is measured or very high resistance replace wire harness 3 Check to make sure intake manifold is not loose and TMAP sensor is not loose
127. erall proper operation Install Spark Plugs 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 24 690 01 Rev K Intake Manifold Components ECH EFI Reassembly MAP or TMAP Design Bracket A Sensor B Fuel Injector C Fuel Rail D Metal Retaining Clip Crankshaft Position Crankshaft Position E Intake Manifold F Sensor Earlier G Sensor Later Design Bracket Install Intake Manifold Install Fuel Injectors Torque Sequence 1 Install intake manifold and new gaskets with wiring harness attached to cylinder heads Slide any wiring harness clips onto appropriate bolts before installing Make sure gaskets are in proper orientation Torque screws in 2 stages first to 7 8 N m 69 in Ib then to 10 5 N m 93 in Ib using sequence shown 2 Install ground terminal to crankcase post with a silver screw Torque to 4 0 N m 35 in Ib into used holes or 6 2 N m 55 in Ib into new holes 3 Install wire harness clip to other crankcase post and torque screw to 4 0 N m 35 in Ib into used holes or 6 2 N m 55 in Ib into new holes 4 Place wire harness conduit in clip and snap clip together NOTE Ensure all parts are clean undamaged and free 9 of debris and make sure electrical connectors have seal in place Lightly lubricate fuel injector O rings
128. ev K EFI SYSTEM BOSCH A WARNING Gasoline is extremely flammable and its vapors can a explode if ignited Store gasoline only in approved Explosive Fuel can cause fires and severe containers in well ventilated unoccupied buildings away e burns from sparks or flames Spilled fuel could ignite if it comes 4 4 Do not fill fuel tank while engine is hot or in contact with hot parts or sparks from ignition Never use running gasoline as a cleaning agent Bosch EFI System gt NOT Sa Gei f TN m 7 lil Gr A Regulator A Fuel Pressure B Valley Baffle Air Deflector Fuel Rail E Intake Manifold Kit F Throttle Position Sensor Module Fuel Injector l ECU Speed Pick up Sensor Speed Sensor Bracket Screw M Intake Gasket N Fuel Filter Fuel Pump Assembly 24 690 01 Rev K KohlerEngines com 59 EFI SYSTEM BOSCH Typical electronic fuel injection EFI system and related components include e Fuel tank and valve e Fuel pump e Fuel filter e Fuel rail e Fuel line s e Fuel injectors e Fuel pressure regulator e Throttle body intake manifold e Electronic control unit ECU e Ignition coils e Engine oil temperature sensor e Throttle position sensor TPS e Speed sensor e Crankshaft position sensor e Oxygen sensor e Wire harness assembly amp affiliated wiring e Malfunction indicator light M
129. f round Connecting rod journal can be ground one 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 deposits collected in oil passages Use these following procedures to remove and replace plug Procedure to 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 large enough to seat against shoulder of plug bore 3 Tighten self tapping screw until it draws plug out of crankshaft Procedure to Install New Plug Use a 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 Flywheel End Oil Seal Remove oil seal from crankcase KohlerEngines com 119 Disassembly Inspection and Service Crankcase Inspection and Service Check all gasket surfaces to make sure they are free of gasket fragments Gasket surfaces must also be free of deep scratches or nicks Inspect main bearing if so equipped for wear or damage refer to Specifications Replace crankcase using a miniblock or short block as required Check cylinder bore wall for scoring In severe cases unburned fuel can cause scuffing and scoring of cy
130. ft Position Sensor 1 Remove screws securing crankshaft position sensor bracket 2 Disconnect electrical connector to crankshaft position sensor Remove Manifold Absolute Pressure MAP Sensor or Temperature Manifold Absolute Pressure TMAP Sensor ECH EFI 1 With a screwdriver slide locking tab on electrical connector 2 Detach connector 3 Remove screw and pull MAP sensor out of intake manifold Remove Fuel Injectors ECH EFI 1 Disconnect electrical connector 2 Remove screw and pull injector out of intake manifold for each injector 24 690 01 Rev K KohlerEngines com 3 When removed pull metal retaining clip connecting fuel injector to fuel injector cap There may be some fuel left in line Any spilled fuel must be cleaned up immediately Remove Intake Manifold 1 Remove screw securing a ring terminal which is part of wiring hamess 2 Remove screws securing intake manifold to cylinder heads Note which screws hold wiring clamp 3 Unclasp wiring harness from clip using a screwdriver 4 Remove intake manifold and intake manifold gaskets 5 Leave wiring harness attached to manifold 109 Disassembly Inspection and Service Cylinder Head Components NS ZA A Zeg S S E Valve Cover Valve Cover Gasket Hex Flange Screw D Rocker Arm Pivot Rocker Arm F Push Rod Hydraulic Lifter H Valve Cap Valve Keeper J Valve Spring Valve Seal L
131. 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 Replacement 1 Shut engine off and remove key Locate fuse holders 2 3 Remove fuse cover and pull out fuse 4 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 98 KohlerEngines com 24 690 01 Rev K Starter System 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 speed 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
132. g 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 beyond allowable range e TPS 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 24 690 01 Rev K 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 KohlerEngines com 87 EFI SYSTEM BOSCH Code 51 32 Pin MSE 1 1 Plastic Cased ECU only Code 52 32 Pin MSE 1 1 Plastic Cased ECU only Component Injector 1 circuit open shorted to Component Injector 2 circuit open shorted to ground or shorted to battery ground or shorted to battery Fault Injector 1 is not functioning because Fault Injector 2 is not functioning because the circuit is open shorted to ground or circuit is open shorted to ground or shor
133. ge It must be 0 20 0 70 mm 0 008 0 027 in Torque bracket screws to crankcase to 8 3 N m 73 in Ib On engines with later design bracket secure bracket assembly to crankcase posts Torque bracket screws to crankcase to 7 3 N m 65 in Ib 3 Push electrical connector on crankshaft position sensor making sure a good connection is made 130 KohlerEngines com Install Valve Covers Torque Sequence 1 Make sure sealing surfaces are clean 2 Make sure there are no nicks or burrs on sealing surfaces 3 Install a new O ring in groove of each cover 4 Position covers on cylinder heads including any clips lifting straps or brackets that were present prior to disassembly Install screws in each cover and finger tighten 5 Torque valve cover fasteners to 6 2 N m 55 in Ib using sequence shown 6 Carefully position breather cover on crankcase Install screws at locations 3 and 4 shown and finger tighten at this time 7T Install inner baffles using 2 remaining screws and finger tighten Do not torque screws at this time they will be tightened after blower housing and outer baffles are installed 24 690 01 Rev K Reassembly External Engine Components Y A Debris Screen B Blower Housing C Outer Baffle D Breather Cover E Oil Sentry F eon dee G Inner Baffle H Debris Screen Guard Install Breather Cover and Inner Baffles 4 Install inner baffles using remai
134. ge formation could indicate over rich fuel settings weak ignition overextended oil change interval or wrong weight or type of oil was used CLEANING ENGINE A WARNING D k Cleaning Solvents can cause severe injury or k 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 lubricating properties of engine oil 24 690 01 Rev K CRANKCASE VACUUM TEST Troubleshooting A WARNING Carbon Monoxide can cause severe nausea fainting or death Avoid inhaling exhaust fumes A WARNING Rotating Parts can cause severe injury Stay away while engine is in operation Engine exhaust g
135. her MTBE and unleaded gasoline blend max 1596 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 24 690 01 Rev K Engine Dimensions with Heavy Duty Air Cleaner Flywheel Side Specifications e amp amp H amp F S OD p BENE V SEND E o Lj if f jene ees tk REENEN Gees 4 o P AD z D T RR CHR pa j S V i j P oe Loo 1 AERE E N Ss NI 2 O zi i E i ka a G Q eo 9 e S amp 342 52 mm A Valve Cover B 451 16 mm 17 762 in C Fuel Pump D 13 485 in 88 28 mm 29
136. hod 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 within system Flow Chart Diagnostic Aids Diagnostic Aid 1 SYSTEM POWER MIL does not illuminate when key is turned ON NOTE MIL is installed by vehicle OEM Twelve volt supply to bulb will be part of vehicle wire harness Kohler key switch model will have MIL on engine with 12V supply to bulb Conclusion e Battery e Main system fuse e MIL light bulb burned out e MIL electrical circuit problem Pin circuits Grey 3 e gnition switch e Permanent ECU power circuit problem Pin circuit Black 18 e Switched ECU power circuit problem Pin circuit Black 15 e ECU grounds e ECU Diagnostic Aid 2 FAULT CODES Refer to Diagnostic Fault Code Summary Diagnostic Aid 3 RUN ON MIL remains ON while engine is running Condition NOTE Either incandescent or LED type bulbs can be used for MIL as long as they do not draw more than 0 1 amps Bulb needs to be rated at 1 4 Watts or less or needs to have a total resistance of 140 O or more LEDs typically draw less than 0 03 amps All current fault codes will turn on MIL when engine is running Diagnostic Aid 4 CRANKSHAFT POSITION SENSOR MIL does not turn off during cranking Condition e Crankshaft position sensor e C
137. horized dealers To find a local Kohler authorized dealer visit KohlerEngines com or call 1 800 544 2444 U S and Canada 24 690 01 Rev K 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 F 20 0 20 32 40 50 60 80 100 ec 30 20 10 0 10 20 30 40 FUEL RECOMMENDATIONS A WARNING Explosive Fuel can cause fires and severe y burns 4 4 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 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 1096 ethyl alcohol 9096 unleaded is acceptable e Methyl Tertiary Butyl Et
138. hrough 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 9 0 N m 80 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 KohlerEngines com 115 Disassembly Inspection and Service Crankcase Components Closure Plate Gerotor Gears Oil Pump Assembly A Closure Plate Seal B Style A C Style A D Style A E Governor Shaft F Governor Washer G Governor Gear H Governor Cup Camshaft J Connecting Rod K Crankshaft L Piston Style B M Piston Pin N Piston pue O Crankcase P PELE Es Q Piston Rings R n e S Ball Style B T Spring Style B U Oil Pump Cover V Outer Gerotor Gear w Oil Pump Assembly X Oil Pick Up Tube O ring Style B Style B Style B Style B Y Piston Style A Remove Camshaft Remove Governor
139. icted exhaust One injector not working Basic engine problem exists TPS faulty or mounting exists Throttle plate in throttle body not fully opening to WOT stop if equipped 24 690 01 Rev K KohlerEngines com 49 EFI SYSTEM ECH Function Test Fault Codes A WARNING Example of Diagnostic Display High Pressure Fluids can puncture skin and wy cause severe injury or death AA Do not work on fuel system without proper training or safety eguipment Fluid puncture injuries are highly toxic and hazardous If an injury occurs seek immediate medical attention Function of fuel system is to provide sufficient 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 2 Disconnect and ground spark plug leads Complete all safety interlock requirements and crank engine for approximately 3 seconds 3 3 3c Me e e e e x 0 One second pause Xt 1 Fault One second pause Code 265 0 ahh att att ate go gg To p One second pause 3c 3 He ME 3 7 Three second pause L A Ue Ue Ye Le 6 3 Remove spark plugs and check for fuel at tips One second pause End Code 61 a If there is fuel at tips of spark plugs fuel pump and i 1
140. id 2 Manually push plunger IN and check if coil holds plunger retracted Do not allow test leads to remain connected to solenoid for a prolonged period of time Continuity 1 Use an ohmmeter set to audible or Rx2K scale and 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 continuity Repeat test several times Condition Conclusion Solenoid fails to activate Replace solenoid No continuity is indicated Plunger fails to stay retracted 102 KohlerEngines com 24 690 01 Rev K Disassembly Inspection and Service A WARNING Accidental Starts can cause severe injury or death Disconnect and ground spark plug lead s before servicing xf Neg Before working on engine or equipment disable engine as follows 1 Disconnect spark plug lead s 2 Disconnect negative battery cable from battery External Engine Components Heavy Duty Air Low Profile Air Low Profile Air n Cleaner 5 Cleaner C Cleaner Cover a Element Cover E Paper Element F Precleaner G gs c e H Dipstick Tube l Dipstick J Spark Plug Lead K Oil Drain Plug L O ring M Oil Cooler N Nipple O Oil Filter 24 690 01 Rev K KohlerEngines com 103 Disassembly Inspection and Service Clean all parts thoroughly as engine is disassembled Only clean parts can be accurately inspected
141. idation 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 If a fault code indicates a problem with an electrical component disconnect ECU connector and test for continuity between component connector terminals and corresponding terminals in ECU connector using an ohmmeter Little or no resistance should be measured indicating that wiring of that particular circuit is OK 24 690 01 Rev K EFI SYSTEM ECH Crankshaft Position Sensor Bracket A Earlier Design Bracket B Later Design Bracket Crankshaft position sensor is essential to engine operation constantly monitoring rotation and speed RPM of crankshaft There are 23 consecutive teeth cast into flywheel One tooth is missing and is used to reference crankshaft position for ECU Inductive crankshaft position sensor with earlier design bracket is mounted 0 20 0 70 mm 0 008 0 027 in from flywheel Later design bracket requires no adjustment During rotation an AC voltage pulse is created within sensor for each passing tooth ECU calculates engine speed from time interval between consecutive pulses Gap from missing tooth creates an interrupted input signal corresponding to specific crankshaft position near
142. il throttle plates can be closed completely 2 Disconnect main harness connector from ECU but leave TPS mounted to throttle body manifold 3 Connect ohmmeter leads as follows See chart on pages 35 Pin MA 1 7 Metal Cased ECU Red positive ohmmeter lead to 12 pin terminal and Black negative ohmmeter lead to 27 pin terminal 24 Pin MSE 1 0 Plastic Cased ECU Red positive ohmmeter lead to 8 pin terminal and Black negative ohmmeter lead to 4 pin terminal 32 Pin MSE 1 1 Plastic Cased ECU Red positive ohmmeter lead to 8 pin terminal and Black negative ohmmeter lead to 4 pin terminal Hold throttle closed and check resistance It should be 800 1200 Q 4 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 9 5 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 64 KohlerEngines com 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
143. in Keyway Deep 152 08 mm 5 987 in Engine Mounting 4 00 mm 0 157 in Toes mum 16 129 UN Oil Filter H Surface Pilot 52 75 mm 2 077 in Center Line Mounting udi R Sele an S 100 0 mm 3 937 in 89 0 mm 3 504 in 51 0 mm 2 008 in V Oil Drain US w 12 28 mm 0 483 in Rectifier Regulator Fuel Pump KohlerEngines com 24 690 01 Rev K Engine Dimensions with Heavy Duty Air Cleaner PTO Side Specifications A 335 04 mm 13 19 in 122 10 mm 4 807 in 65 0 mm 2 559 in Muffler Mounting 75 42 mm 2 969 in 50 00 mm 1 969 in Lift Strap Oil Fill Location 30 Exhaust Port 2 5 16 24 UNC 2B in 2 X M8 X 1 25 17 mm 0 669 in 2 X 306 24 mm o 12 136 in 20 5 mm 135 0 807 in Deep Deep 127 mm 5 0 in B C 3 8 16 UNC 2B in 21 mm 0 827 in Deep 165 1 mm 6 5 in B C 7 16 14 UNC 2B in 21 mm 0 827 in Deep 165 1 mm 6 5 in B C Center Line Mounting Hole A 177 8 mm 7 0 in Pilot Diameter Engine Mounting Surface Solenoid Shift Starter 283 58 mm 11 164 in Muffler Mounting 50 00 mm 1 969 in Exhaust Port 1 M8 X 1 25 4 Studs 45 24 690 01 Rev K KohlerEngines com Specifications Engine Dimensions with Heavy Duty Air Cleaner Starter Side 50 0 mm 1 969 in Center Line Spark Plug 432 58 mm 17 031 in 12 0 mm 0 472 in
144. in circuits 12 25 and or 27 damaged e Pin circuit wiring or connectors e Pin circuits 12 25 and or 27 routed S bere Sere 10 for 24 Pin MSE near noisy electrical signal coils inis v and or TU Tor in Get gne 1 0 Plastic Cased ECU e Intermittent 5 volt source from ECU Pin s 9 and or 10 for 32 Pin MSE pin circuit 25 1 1 Plastic Cased ECU Engine Wiring Harness Related ECU Harness Related 24 Pin MSE 1 0 Plastic Cased ECU HD e ECU to harness connection problem e Pin circuits 4 8 and or 14 damaged wiring connectors e Pin circuits 4 8 and or 14 routed near noisy electrical signal coils alternator e Intermittent 5 volt source from ECU pin circuit 14 Engine Wiring Harness Related 32 Pin MSE 1 1 Plastic Cased ECU 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 84 KohlerEngines com 24 690 01 Rev K EFI SYSTEM BOSCH Code 31 Code 32 Component Fuel Mixture or Oxygen Sensor Component Oxygen Sensor Fault System too lean Oxygen sensor not Fault No change in sensor output signal sending expected voltage to ECU Condition Open loop operation only may cause Condition System operates under open loop a drop in system performance and fuel
145. incorrect ECU Reset and TPS Learn or Fails to Start TPS faulty When Cold Engine temp sensor faulty Faulty coils Low system voltage Faulty injectors Faulty battery Loose or corroded connections 48 KohlerEngines com 24 690 01 Rev K EFI SYSTEM ECH Troubleshooting Guide Condition Possible Cause Engine Starts Hard or Fails to Start When Hot Faulty spark plugs Fuel pump not running Fuel pressure low Insufficient fuel delivery TPS set incorrect ECU Reset and TPS Initialization Crankshaft position sensor loose or faulty TPS faulty Engine temp sensor faulty Faulty injectors Engine Stalls or Idles Roughly cold or warm Faulty spark plugs Insufficient fuel delivery TPS set incorrect TPS faulty Faulty engine temperature sensor Faulty injectors Engine Misses Hesitates or Stalls Under Load Low Power Fuel injector s fuel filter fuel line or fuel pick up dirty restricted Dirty air cleaner Insufficient fuel pressure or fuel delivery Vacuum intake air leak Improper governor setting adjustment or operation 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 Plugged restr
146. ine container or equipment fuel tank 3 Turn on key switch to activate pump and check System pressure on gauge It may take several key cycles to compress air introduced into system and reach regulated pressure If system pressure of 39 psi 3 is observed wiring 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 or too low replace fuel pump module 4 fpump did not activate step 3 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 during six second prime process 5 f no voltage is observed connect red lead of meter to red wire of plug and black lead to a good ground while key is still ON KohlerEngines com 47 EFI SYSTEM ECH 6 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 7 If 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 2 and 3 to verify correct pressure b If pump still does not operate replace it High Pressure Fuel Line High pre
147. ing maximum angle of operation may cause engine damage from insufficient lubrication gt Lubricate threads with engine oil prior to assembly Any and all horsepower hp references by Kohler are Certified Power Ratings and per SAE J1940 amp J1995 hp standards Details on Certified Power Ratings can be found at KohlerEngines com 24 690 01 Rev K KohlerEngines com 13 Specifications TORQUE SPECIFICATIONS ECH630 ECH680 ECH730 ECH749 CH26 CH735 CH745 Crankcase Breather Cover Fastener 11 1 m 100 in Ib into new holes m 65 in Ib into used holes 7 3 N m 65 in Ib Oil Temperature Sensor into breather cover 7 3 N m 65 in Ib Oil Sentry into breather cover 4 5 N m 40 in Ib Oil Drain Plug 13 6 N m 10 ft Ib Cylinder Head Hex Flange Nut torque in 2 increments Head Bolt torque in 2 increments first to 16 9 N m 150 in Ib finally to 33 9 N m 300 i n Ib first to 22 6 N m 200 in Ib finally to 41 8 N m 370 i n Ib Rocker Arm Screw 18 1 N m 160 in Ib Fan Flywheel Fan Fastener 9 9 N m 88 in Ib Flywheel Retaining Screw 71 6 N m 52 8 ft bi 66 4 N m 49 ft Ib Metal Debris Screen Fastener to flywheel 9 9 N m 88 in Ib Plastic Debris Screen Fastener to fan 4 0 N m 35 in Ib Fuel Pump Module Baffle Fastener 11 9 N m 105 in Ib M
148. intake or exhaust and cylinder 1 or cylinder 2 Install hydraulic lifters into their appropriate location in crankcase Do not use a magnet Torque screw to 4 0 N m 35 in Ib Cylinder Head Components If breather reeds and stops were removed from crankcase reinstall them at this time and secure with screw Gasket A Valve Cover B Valve Cover Gasket Hex Flange Screw Rocker Arm Pivot E Rocker Arm F Push Rod Hydraulic Lifter Valve Cap l Valve Keeper J Valve Spring Valve Seal M M Cylinder Head N Cylinder Head Valve Dowel Pin 24 690 01 Rev K KohlerEngines com 127 Reassembly Valve Stem Seals These engines use valve stem seals on intake valves and on exhaust valves Always use a new seal whenever valve is removed or if seal is deteriorated or damaged in any way Never reuse an old seal Assemble Cylinder Heads Prior to installation lubricate all components with engine 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 Intake and exhaust valves Valve spring retainers Valve springs Valve spring caps Valve spring keepers Install Cylinder Heads Torque Sequence NOTE Cylinder heads must be attached with original type of mounting hardware using either screws or mounting studs with nuts and washers Do not intermix comp
149. 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 4 Install adapter into spark plug hole but do not attach it to tester at this time 5 Turn regulator knob completely counterclockwise 6 Connectan air source of at least 50 psi to tester 7 Turn regulator knob clockwise increase direction until gauge needle is in yellow set area at low end of scale 8 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 Condition Conclusion Air escaping from crankcase breather Ring or cylinder worn Air escaping from exhaust system Defective exhaust valve improper seating Air escaping from intake Defective intake valve improper seating Gauge reading in low green zone Piston rings and cylinder in good condition Gauge reading in moderate yellow zone Engine is still usable but there is some wear present Customer should start planning for overhaul or replaceme
150. ip of valve needle or external weeping around injector O rings 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 Refer to Disassembly for removal of injector 1 Remove manifold mounting bolts and separate throttle body manifold from engine leaving TPS high pressure fuel line injectors and fuel line connections intact Discard old gaskets 2 Position manifold assembly over an appropriate container to capture fuel and turn key switch ON to activate fuel pump and pressurize system Do not turn switch to START position NOTE Fuel pump module pins are coated with a thin layer of electrical grease to prevent fretting and corrosion Do not attempt to remove electrical grease from fuel pump module pins 3 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 4 Depressurize fuel system 5 Clean any dirt accumulation from sealing mounting area of faulty injector s and disconnect electrical connector s 6 Pull retaining clip off top of injector s Remove screw holding injector s from manifold 24 690 01 Rev K 7 Reverse appropriate procedures to install new injector s and reassemble engine Use new O rings and retai
151. iring harness EFI SYSTEM BOSCH 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 anything but wait until MIL shuts off This indicates that this procedure has been completed successfully 9 Shutoff 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 ou
152. iston Pin End 1 D 21 C 70 F New Max Wear Limit 0 015 0 028 mm 0 0006 0 0011 in 17 015 17 023 mm 0 6699 0 6702 in 17 036 mm 0 6707 in 0 015 0 028 mm 0 0006 0 0011 in 17 015 17 023 mm 0 6699 0 6702 in 17 036 mm 0 6707 in Crankcase Governor Cross Shaft Bore D New Max Wear Limit 6 mm Shaft New Max Wear Limit 8 mm Shaft New Max Wear Limit 8 025 8 075 mm 0 3159 0 3179 in 8 088 mm 0 3184 in 6 025 6 050 mm 0 2372 0 2382 in 6 063 mm 0 2387 in 8 025 8 075 mm 0 3159 0 3179 in 8 088 mm 0 3184 in Crankshaft End Play free End Play w thrust bearing components Bore in crankcase New Max Wear Limit 0 070 0 590 mm 0 0028 0 0230 in 0 070 1 190 mm 0 0028 0 0468 in 40 972 40 997 mm 1 6131 1 6141 in 41 011 mm 1 6146 in 0 070 0 590 mm 0 0028 0 0230 in 0 070 1 190 mm 0 0028 0 0468 in 40 965 41 003 mm 1 6128 1 6143 in 41 016 mm 1 6148 in Bore in closure plate New 40 974 41 000 mm 1 6131 1 6141 in 40 987 40 974 mm 1 6136 1 6131 in Crankshaft to Sleeve Bearing closure plate Running Clearance New Crankshaft Bore In Closure Plate to Crankshaft Running Clearance New 0 03 0 12 mm 0 001 0 005 in 0 039 0 087 mm 0 0015 0 0034 in 0 03 0 09 mm 0 0012 0 0035 in 0 039 0 074 mm 0 0015 0 0029 in Flywheel End Main Bearing Journal OD New O D Max Wear Limit Max Taper Limit M
153. it left in cylinder bore can destroy an engine in less than 1 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 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 and apply a light coating of engine oil to prevent rusting 24 690 01 Rev K Measuring Piston to Bore Clearance Piston Detail Style A Style B il Jr Model ECH630 ECH680 Dimension A 6 mm 0 2362 in Dimension B 13 mm 0 5118 in ECH730 ECH749 6 mm 0 2362 in 6 mm 0 2362 in CH26 CH735 CH745 6 mm 0 2362 in 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 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 i
154. j pepueuuu29J SIJ ege wajsAs jeu29je 1ua aud oj posn aq nu j00q 10 a nid weds aAjsise e sayya uy Grid eds a nsisa v SseuJeu an SISSeu Jo sinzia sebejoa 10 enjoe uaamjea sausap jueAeud 01 eap juan STS S jo ssejpyebau 184jo 4383 jo A Z OF uit iSS pu LLP pue Z Lf G8 r SHNS uo Beyo au Buruejs Bupnp yesas NOA wenaud oj uorisod un ail oj ues euj WOU dams Sj e ou se z Lr pue cg pg syn 0 ebeyo juejsuo2 e uregureu nu Ve uonjuf eu SILON NOILV TIVISNI W31SAS TVH3N35 AYBLLVE v 3L1ON SONIGNNOSDS 33S 7 ONnONO 1931199 Ky Ji 9 310N QNnONO 33S usw 80123NNOO st kg E 4 No Le v c v d Si m Bi m a H d d d d H E kedy YMOd NIVN 49712359 Gain i SITOA Z Lu NOILVZIVILINI Sal 8 310N eo z o 3 ul as oz 1ir YOBMY1 30SN3S Josuas asnjojadwaj 40 0 W Gero es E Z MO123 NI to ot sv ze 1ir ym sja o n o L o ei o i o lt elo 6 ia TL e v mon Bupuno o KS o omy Gi sosedes omi voues vpqeer1 ii inar v L 30123fPNI to aa Z L Q33dS 3NION3 MOSN3S J or 1r 6 1r QNnON9 ON sz ir HOLIMS A134vS 6 ON 310N 1v33N39 33S 79 KohlerEngines com 24 690 01 Rev K EFI SYSTEM BOSCH Fuel System Fault Codes A WARNING Fuel System Under Pressure Fuel system operates under high pressure System pressur
155. l adjust fuel and ignition timing based upon ambient temperature engine temperature and loads present In cold conditions idle speed will probably be different 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 servicing 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 igni
156. linder 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 blocked cooling fins or from inadequate or contaminated lubrication 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 refer to Specifications then select nearest suitable oversize of either 0 25 mm 0 010 in or 0 50 mm 0 020 in Resizing to one of these oversizes will allow usage of available oversize piston and ring assemblies First resize using a boring bar then use these following procedures for honing cylinder Honing Detail A 23 33 Crosshatch NOTE Kohler pistons are custom machined to exacting tolerances When oversizing a cylinder it should be machined exactly 0 25 mm 0 010 in or 0 50 mm 0 020 in over new diameter Specifications Corresponding oversize Kohler replacement piston will then fit correctly 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 inst
157. lues is outside of specified range and output transitions in a smooth manner reset ECU and run test again Since there is no longer any wear elements inside sensor most likely faults will be in electrical connections between sensor and wire harness and wire harness to ECU With service software communicating to ECU and engine not running a small load or gentle back and forth motion can be applied to connectors or wires just outside connectors to detect a faulty connection If only a volt meter is available Measure voltage supply to sensor from ECU This voltage should be 5 00 0 20 volts This can be measured by gently probing terminals B amp C on harness side with TPS connector removed from TPS and key ON This will generate a P0122 fault that can be cleared with an ECU reset If voltage is low battery harness and ECU should be investigated If supply voltage is good plug sensor back into harness Probe sensor signal wire with volt meter terminal A at TPS or pin Black 12 at ECU This signal should start between 0 6 1 2 volts at low idle and grow smoothly as throttle is opened to 4 3 4 8 volts at full open WOT Since there is no longer any wear elements inside sensor most likely faults will be in electrical connections between sensor and wire harness and wire harness to ECU 24 690 01 Rev K EFI SYSTEM ECH Replace Magnet Assembly A B Magnet Installation Depth Magnet assembly is captured in a small pla
158. lug cap 2 Install adapter into oil fill dipstick tube opening upside down over end of a small diameter dipstick tube or directly into engine if a tube is not used Insert barbed gauge fitting into hole in stopper 3 Run engine and observe gauge reading Analog tester needle movement to left of 0 is a vacuum and movement to right indicates a pressure Digital tester depress test button on top of tester Crankcase vacuum should be a minimum of 10 2 cm 4 in of water If reading is below specification or if pressure is present check table below for possible causes and conclusions 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 fasteners Replace all worn or damaged seals and gaskets Make sure all fasteners are tightened securely Use appropriate torque valves and sequences when necessary Piston blow by or leaky valves confirm by inspecting components Restricted exhaust Recondition piston rings cylinder bore valves and valves guides Check exhaust screen spark arrestor if equipped Clean or replace as needed Repair or replace any other damaged restricted muffler or exhaust system pa
159. m operating temperature 375 C 709 F e Poor ground path from sensor to engine sensor grounds through shell see Oxygen Sensor section 24 690 01 Rev K KohlerEngines com 85 EFI SYSTEM BOSCH Code 33 Component Oxygen Sensor Fuel System Fault System too rich Temporary fuel adaptation control is at upper limit Condition 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 e Sensor contaminated or damaged e Exhaust leak e Poor ground path e Pin circuit wiring or connectors Pin 10 for 35 Pin MA 1 7 Metal Cased ECU Pin 11 for 24 Pin MSE 1 0 Plastic Cased ECU Pin 20 for 32 Pin MSE 1 1 Plastic Cased ECU 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 circuit 17 for metal cased ECU pin circuit 2 for plastic cased ECU 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 e Combustion air air cleaner dirty restricted intake leak throttle bores Base engin
160. m 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 2 digit blink codes available based upon style of ECU are listed on pages 70 71 and 72 Codes are accessed 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 24 690 01 Rev K EFI SYSTEM BOSCH Example of Diagnostic Display 1 Diagnostic display initiated through ignition key sequencing 2 Long Pause Short Pauses x 4 L 3 1 hemm Code 32 4 j Long Pause 5 m a Code 61 1 S T ay Light remains on at end of transmission
161. mbly Install Oil Cooler if equipped NOTE To identify various parts and assembly of throttle control panel refer to External Governor Control Components 1 Secure throttle control panel to crankcase with thread forming screws 2 Attach governor spring to previously marked hole on governor lever Install Air Cleaner Assembly Refer to Air Cleaner Intake Air for air cleaner reassembly procedure Heavy Duty Air Cleaner 1 Install air cleaner assembly onto throttle body mounting studs Secure with nuts and screws Torque nuts to 7 4 9 0 N m 65 5 80 in Ib and torque screws to 4 6 6 9 N m 41 61 in Ib Low Profile Air Cleaner 1 Verify O ring is present around machined O D of throttle body and place air cleaner base onto throttle body studs Secure air cleaner base using nuts Attach air cleaner base bracket to cylinder heads with screws behind any control panel or bracket Attach air cleaner base to lower bracket with 2 M5 screws through lower section of base Torque nuts to 6 2 7 3 N m 55 65 in Ib and 2 lower M5 mounting screws when applicable to 4 0 N m 35 in Ib 2 Install air cleaner components as described in Air Cleaner Intake Setting Initial Governor Adjustment ECH EFI 1 Move governor lever toward throttle body as far as it will go wide open throttle and hold in position 2 Insert a nail into hole on cross shaft and rotate shaft counterclockwise as far as it will turn then torq
162. 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 EFl 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 24 690 01 Rev K In an emergency situation simply disconnecting and reconnecting connectors may clean up contacts enough to restore operation at least temporarily If a fault code indicates a problem with an electrical component disconnect ECU connector and test for continuity between component connector terminals and corresponding terminals 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 for each style of ECU connector is provided on pages 63 65 and 67 KohlerEngines com 73 EFI SYSTEM BOSCH 35 Pin MA 1 7 Metal Cased ECU Systems Pin Component 1 Ignition Coil 1 2 Not used 3 Engine Speed Sensor 4 ECU Production Test Terminal 5 Not Used 6 Not Used 7 Not Used 8 TPS Initialization Terminal 9 Engine Ground 10 O2 Sensor 11 Not Used 12 Throttle Positio
163. minimum output of 13 5 liters per hour and regulated at 270 kilopascals 39 psi 24 690 01 Rev K When key switch is turned ON and all safety switch reguirements are met ECU activates fuel pump module for about sik seconds 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 Precision components inside fuel pump module are not serviceable DO NOT attempt to open fuel pump module Damage to components will result and warranty will be void Because fuel pump module is not serviceable engines are equipped with a special 10 micron EFI fuel filter to prevent harmful contamination from entering module If there are two filters in system one before lift pump will be a standard 51 75 micron filter and one after lift pump will be special 10 micron filter Be sure to use an approved 10 micron filter for replacement High pressure fuel line is an assembly of hoses injector caps and a fuel connector to fuel pump module High pressure fuel line feeds fuel to top of injectors through injector caps Caps are fastened to intake manifold and injectors are locked into place A small retaining clip
164. mm 0 039 0 117 in of spring extending beyond end of idle speed screw 2 Secure spring onto screw with a small amount of Permabond LM 737 or equivalent Loctite adhesive Do not get any adhesive on free coils of spring 3 Start engine and recheck idle speed settings after sufficient warm up Readjust as required 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 KohlerEngines com 71 EFI SYSTEM BOSCH If governor throttle components are all intact but you think there may be a problem with adjustment follow Procedure A to check setting If governor lever was loosened or removed go immediately to Procedure B to perform initial adjustment A Checking Initial Adjustment 1 Unsnap plastic linkage bushing attaching throttle linkage to governor lever Unhook damper spring from lever separate linkage from bushing and remove bushing from lever Mark hole position and unhook governor spring from governor lever 2 Check if engine has a high speed throttle stop screw installed in manifold casting boss a On engines without a st
165. mmet and backing plate 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 Check drive pinion 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 clutch housing and rotating pinion Pinion should rotate in only 1 direction Brushes and Springs Detail A 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 24 690 01 Rev K Armature Components and Details A Commutator O D B Mica Insulation Insulation Check D Armature Coil Continuity Check 4 Shi Clean and inspect commutator outer surface Mica insulation must be lower than commutator bars undercut to ensure proper operation of commutator Use an ohmmeter set to Rx1 scale Touch probes between 2 different segments of commutator and check for continuity Test all
166. mp 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 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 forme
167. n 24 Pin ka Blink P Code Ap MA 1 7 MSE 1 0 1 1 Code plicable to Connection or Failure Description Metal Plastic Plastics Note 32 Pin MSE Cased Cased Gasca 1 1 ECU Sys ECU ECU Sys ECU tem Only System tem System 31 P0132 O Sensor Circuit Shorted to Battery Y N Y 3 O Sensor Circuit No Activity De N 32 P0134 tested N N 8 33 P0175 System too Rich Y Y Y 78 33 P0020 O Sensor Control at Upper Limit Y Y Y 8 34 P0171 Maximum Adaption Limit Reached Y Y Y 8 34 P0172 Minimum Adaption Limit Reached T Y Y 8 Temperature Sensor Circuit Shorted Y 42 P0117 to Ground Y Y Temperature Sensor Circuit Open Y az PHE Circuit or Short to Battery T 3 Failure Completing Autolearn TPS 43 NA Offset below minimum allowable limit NA NA y Failure Completing Autolearn TPS 44 N A offset above maximum allowable N A N A yY limit 51 P1260 Injector 1 Open Circuit N A N A Y 51 P0261 Injector 1 Short Circuit to Ground N A N A Y 51 P0262 Injector 1 Short Circuit to Battery N A N A Y 52 P1263 Injector 2 Open Circuit N A N A Y 52 P0264 Injector 2 Short Circuit to Ground N A N A Y 52 P0265 Injector 2 Short Circuit to Batt N A N A Y 55 P1651 Diagnostic Lamp Open Circuit N A N A Y Diagnostic Lamp Short Circuit to 55 P1652 Ground N A N A Y 55 P1653 Diagnostic Lamp Short Circuit to N A N A Y Battery 82 KohlerEngines com 24 690 01 Rev K EFI SYSTEM BOSCH OBD2 35
168. n stem end Replace valves found to be in bad condition 112 KohlerEngines com 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 lI 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 24 690 01 Rev K Disassembly Inspection and Service 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 di
169. n Sensor 13 Not Used 14 Oil Temperature Sensor 15 Not Used 16 ECU Permanent Battery Voltage 17 ECU Switched Battery Voltage 18 Engine Ground 19 Ignition Coil 2 20 Vehicle Ground 21 Engine Speed Sensor 22 Not Used 23 Not Used 24 Not Used 25 Throttle Position Sensor 26 Not Used 27 Throttle Position Sensor Oil Temperature Sensor 28 Power Relay 29 Not Used 30 Not Used 31 Malfunction Indicator Light 32 Not Used 33 Vehicle Ground 34 Not Used 35 Fuel Injectors picos n c3 o O WE GMM RJ NO BN KR NN NN a n SCO ON OO QM CO do d N m QX L CQ CO Ep yn a Oo cops A EE 0 Gk 74 KohlerEngines com 24 690 01 Rev K EFI SYSTEM BOSCH sissouo 03 oy I Ze mail d paana ny am 03 eujDue aya Woy downs Bu k a ne d EN eii oi S maas gan 2 ejqi5Sod SD qUOYS 50 eq 07 uoj190 PUNOJ oi p19 US WOUJ SA peus d Za 1109 voou yoolq eujbuo 03 av N Bujanoy awe uoau met eujBue o3 yodgay ml 9 46308 Deu 9079 aujBua 03 eeng Ruag309 8 ejqissod so 1193 07 28070 so gien 03 yoojay Lat andang uoja UB uoqo0fUy Y DESS DEn BION OAV BL sp main Ty heli toads seine men 6 S310N bu IPUNOJI aus Bujunp uoj30uede Nga Joy eBo310 uejsfis unujuju s310 A ujpqu bu 3snm Ruagqoq eui 1 615 p Bujung 6 fiaowou eA 1dopo ujoqujou o3 Z jo Mbup 3ueJuno D YAJA 8770A 4 40 goio mejsfis unujuju
170. n be checked as follows 1 Remove temperature sensor from throttle body 2 Allow it to reach room temperature 20 C 68 F 3 Unplug Black connector from ECU 4 With sensor still connected check temperature sensor circuit resistance between Black pin 10 and 8 pin terminals Value should be 3100 3900 O 5 Unplug sensor from wire harness and check sensor resistance separately across two pins Resistance value should again be 3100 3900 O a If resistance is out of specifications replace temperature sensor b If itis within specifications proceed to Step 6 6 Check circuits input ground from main harness connector to sensor plug for continuity damage etc Connect one ohmmeter lead to Black pin 8 in main harness connector as in step 4 Connect other lead to terminal 1 in sensor plug Continuity should be indicated Repeat test between Black pin 10 and terminal 2 in sensor plug 42 KohlerEngines com A sealed non serviceable assembly A faulty sensor must be replaced If a blink code indicates a problem with manifold absolute pressure sensor it can be tested as follows 1 Make sure all connections are making proper contact and are free of dirt and debris Remove blower housing Slide locking tab out and pull off manifold absolute pressure connector Turn key Switch to ON and check with a volt meter by contacting red lead to pin 1 and black lead to pin 2 There should be 5 volts present indicating ECU and
171. nal 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 2 or 3 times to determine condition of part 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 20 25 amp rectifier regulators 1 2 3 4 96 Connect tester ground lead with spring clamp to body of rectifier regulator Connect red lead from tester to middle terminal labeled B Connect black leads from tester to both outer AC terminals on rectifier regulator Plug tester into proper AC outlet power 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 Press TEST button until a click is heard and then release Momentarily one of four status lights will illuminate indicating partial condition of part KohlerEngines com 24 690 01 Rev K Condition Electrical System Conclusion 20 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 u
172. nal specified speed setting 6 Turn key ignition OFF and count to 10 seconds Learn procedure is complete KohlerEngines com 35 EFI SYSTEM ECH JO O UUOD onsouBeiq fv Josues eJnjejeduus JOSU9S Josues JINSS Jd JOSU9S div exexul IV aimesedwaiio HV onge poust 9V uonsogemou JV 0suesue Axo av JOSU9S uonisog weusyueiS QV CH 1100 uou ov L OD uou av cit Jojoefuj jon j vv LR Jojeful jon j Z J0198uuo Aad A JO DBUUOD yoe g X esnJ VOL M JIN U9IIMS 98Jnssa9Jg IO n JOJO Jo1J6 S 1 JoyoouuOyd jeulwde 9 S duung jan A apeg o esnJ YOC d JojejnDes 1eynoes O JO e S N xoelg N Kal 1 SU M UPL r xuld I ejdung H enig eq 9 u 19 eq E u 19 4417 J MOIS 0 JUMO 9 yoe q Pey 9 pad Y LWO OO0O000000 J 6 4OSUdS nzes dw 11e JYEJU pue Josues dv a1g16das y m seuiBuo 10328uuo juwa 9 Wesibelg DUU 142 ssouJep BULIM 24 690 01 Rev K KohlerEngines com e e EFI SYSTEM ECH JO O UUOD onsouBeiq fv Josues eJnje1eduus JOSU9S Josues eJnssaJgd JosuesS diy exeyul IV emejeduejgo PV ainjosaypioyuew 9V uonsogemoig dV 9 esueD xo av JOSU9S uonisog yeusyuerg QV cit 1100 UoUB ov L lop uous av cit Joel jen VV L 10 oefuj jen Z J0198uu0 Aad A JO DBUUOD 0619 X esnJ voL M TW A YOUMS 98JnsSaJg IO n JOJON J91J61S 1
173. nd hose clamps when installing a regulator A new 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 regulator and mounting bracket Set mounting bracket into position b Secure the 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
174. nd 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 fault 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 refer to Tools and Aids 24 690 01 Rev K ECU requires a minimum of 7 0 volts to operate Adaptive memory in ECU is operational whenever required 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
175. never three conditions for closed loop operation above are not being met ECU is brain or central processing computer of entire EFI 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 intake air temperature exhaust oxygen levels manifold absolute pressure and battery voltage 24 690 01 Rev K ECU compares input signals to programmed maps in its memory to determine appropriate fuel and spark reguirements 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 eguipped on eguipment control panel store fault code in its fault 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 ECU requires a minimum of 6 0 volts to operate To prevent engine over speed and possible failure a rev limiting feature is programmed into ECU If maximum RPM limit 4500 is exceeded
176. ng disassembly make sure they are reinstalled in sequence shown A different procedure will have to 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 spacer and stick it onto thrust washer Install closure plate onto crankcase without applying RTV sealant and secure it with only 2 or 3 fasteners at this time Use a dial indicator to check crankshaft end play End play should be 0 070 1 190 mm 0 0028 0 0468 in Shim spacers are available in 3 color coded thicknesses if adjustment is needed 124 KohlerEngines com Clearance Specifications Crankshaft End Play Shims Green 0 8366 0 9127 mm 0 8750 mm 0 034 in Nominal Yellow 1 0652 1 1414 mm 1 1033 mm 0 043 in Nominal Red 1 2938 1 3700 mm 1 3319 mm 0 052 in Nominal Remove closure plate If end play requires adjustment remove original spacer and install appropriate size shim spacer in its place Then follow procedure under Install Closure Plate Assembly Install Closure Plate Oil Seal Oil Seal Details A Oil Seal B 8 0 mm 0 314 in C Seal Depth 1 Checkto make sure the
177. ng 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 KohlerEngines com 24 690 01 Rev K Carbon Fouled T Gg Soft sooty black deposits indicate incomplete combustion caused by a restricted air cleaner over rich carburetion weak ignition or poor compression Overheated Chalky white deposits indicate very high combustion temperatures This condition is usually accompanied by excessive gap erosion Lean carburetor settings an intake air leak or incorrect 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 requirement depends on engine size application and starting temperatures Cranking requirements increase as temperatures decrease and battery capacity shrinks Refer to equipment s operating instructions for specific battery requirements Battery Size Recommendations Temperature Battery Required Above 32 F 0 C 200 cca minimum O F to 32 F 18 C to 0 C 250 cca minimum 5 F to O F 21 C to 18 C 300 c
178. ng into position over front edge of inner baffles Start a few screws to hold it in place 2 Position outer baffles and secure using M6 screws Install M6 screws 20 mm long into intake port side of cylinder heads including any lifting strap Install 2 M6 screws 16 mm long into exhaust port side of cylinder head Install 2 short M5 screws 10 mm long in upper mounting holes of outer baffles into backing plate Be sure any leads are routed out through proper offsets or notches so they will not be pinched between blower housing and baffles 3 Insert and tighten all remaining blower housing and baffle screws with exception of rectifier regulator grounding bracket lead screw Torque all blower housing and baffle M6 screws assembled into aluminum to 10 7 N m 95 in Ib for a new hole or 7 3 N m 65 in Ib for a used hole Torque all blower housing and baffle M5 screws assembled into sheet metal backing plate to 2 8 N m 25 in Ib for new holes or 2 3 N m 20 in Ib for used holes 4 Torque breather cover screws to 11 3 N m 100 in Ib into new holes or 7 3 N m 65 in Ib into used holes in sequence shown Note first screw is torqued a second time Install Rectifier Regulator 2 Torque black rectifier regulator screws to 1 4 N m 12 6 in Ib a Torque silver or green ground strap screw to 2 8 N m 25 in Ib into new holes or 2 3 N m 20 in Ib into used holes b Ground lead that s
179. ning clips any time an injector is removed new replacement injectors include new O rings and retaining clips Lubricate O rings lightly with clean engine oil Use installation tool provided with O rings to install new upper O ring Place tool into fuel injector inlet Place one side of O ring into O ring groove and roll O ring over tool onto fuel injector Torque screw securing fuel injector caps and blower housing mounting screws to 7 3 N m 65 in Ib and intake manifold and air cleaner mounting screws to 10 5 N m 93 in Ib An ECU Reset will need to be completed 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 stumbling during acceleration or triggering of fault codes related to fuel delivery Injector clogging is usually caused by a buildup of deposits on director 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 Ignition Coil If a coil is determined to be faulty replacement is n
180. ning screws and finger tighten Do not torque screws at this time they Torque Sequence will be tightened after blower housing Install Oil Temperature Sensor ECH EFI NOTE Ensure part is clean undamaged and free of debris and make sure electrical connector has seal in place 1 Lightly lubricate oil temperature sensor O ring and install oil temperature sensor into breather cover 2 Torque sensor to 7 3 N m 65 in Ib 3 Push electrical connector on oil temperature sensor making sure a good connection is made Install Oil Sentry If So Equipped 1 Apply pipe sealant with Teflon Loctite amp 592 PST Thread Sealant or equivalent to threads of Oil 1 Besure sealing surfaces of crankcase and breather Sentry switch and install it into breather cover cover are clean of old gasket material Do not scrape Torque to 4 5 N m 40 in Ib surfaces as this could result in leakage Use a new gasket when installing breather cover 2 Connect wire lead green to Oil Sentry terminal 2 Check to make sure there are no nicks or burrs on sealing surfaces 3 Position breather gasket and cover on crankcase Install screws in locations 3 and 4 Finger tighten at this time 24 690 01 Rev K KohlerEngines com 131 Reassembly Install Blower Housing and Outer Baffles NOTE Do not completely tighten screws until all items are installed to allow shifting for hole alignment 1 Slide blower housi
181. nside 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 24 690 01 Rev K KohlerEngines com Disassembly Inspection and Service 121 Reassembly Crankcase Components Closure Plate Gerotor Gears Oil Pump Assembly A Closure Plate Seal B Style A C Style A D Style A E Governor Shaft F Governor Washer G Governor Gear H Governor Cup Camshaft J Connecting Rod K Crankshaft L Piston Style B M Piston Pin N Piston pue O Crankcase P PELE Ee Q Piston Rings R n e S Ball Style B T Spring Style B U Oil Pump Cover V Outer Gerotor Gear w Oil Pump Assembly X Oil Pick Up Tube O ring Style B Style B Style B Style B Y Piston Style A NOTE Make sure engine is assembled using all specified torque values tightening sequences and clearances Failure to observe specifications could cause severe engine wear or damage Always use new gaskets Apply a small amount of oil to threads of critical fasteners before assembly unless a Sealant or Loctite is specified or preapplied Make sure all traces of any cleaner are removed before engine is assembled and placed into operation Even small amounts of these cleaners can quickly break down lubricating pro
182. nsor Engine Wiring Harness Related signal with VOA and see Oxygen e Broken or shorted wire in harness Sensor ECU pin Black 6 e Wiring from Ignition Engine Wiring Harness Related e Pin circuit wiring or connectors ECU Related ECU pin Black 10 12 16 and 17 e Circuit controlling injector 2 damaged Low Fuel Pressure Code 0230 e Plugged filters Component Fuel Pump e Bad lift pump Fault Circuit Low Voltage or Open Oxygen Sensor Related Condition Shorted or open connection e Sensor connector or wiring problem Conclusion Fuel Pump Related e Exhaust leak e Fuel pump module open or shorted e Poor ground internally Poor system ground from ECU to engine Engine Wiring Harness related causing rich running while indicating lean e Broken or shorted wire in harness ECU pin Black 9 or Grey 17 Fuel pump module connection See Fuel Components ECU Related e ECU is damaged Code 0201 Code 0232 Component Fuel Injector Fault Injector 1 Circuit Malfunction EURIDORSHE Fuel Pump Condition Injector damaged or faulty shorted or Fault Circuit High Voltage open connection Condition Shorted connection Conclusion Injector Related Conclusion Fuel Pump Related e Injector coil shorted or opened e Fuel pump module damaged internally Engine Wiring Harness Related Charging Output System Too High e Broken or shorted wire in harness ECU pin Black 5 e Wiring from Ignition ECU Related e Circuit controlling injector 1 damag
183. nt Gauge reading in high red zone Rings and or cylinder have considerable wear Engine should be reconditioned or replaced 28 KohlerEngines com 24 690 01 Rev K AIR CLEANER These systems are CARB EPA certified and components should not be altered or modified in any way Low Profile Air Cleaner A Air Cleaner Cover B Air Cleaner Knob C Wing Nut D Element Cover E Rubber Seal F Precleaner G Paper Element H Air Cleaner Base Heavy Duty Air Cleaner Air Cleaner Housing J Element K End Cap L Dust Ejector Valve M Retaining Clip N Inner Element O Ejector Area P Inlet Screen Q Filter Minder 24 690 01 Rev K Air Cleaner Intake 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 Low Profile Loosen knob and remove air cleaner cover Precleaner 1 Remove precleaner from paper element 2 Replace or wash precleaner in warm water with detergent Rinse and allow to air dry 3 Saturate precleaner with new engine oil squeeze out excess oil 4 Reinstall precleaner over paper element Paper Element 1 Clean area around element Remove wing nut element cover and paper element with precleaner 2 Separate precleaner from element service precleaner and replace paper element 3
184. o locate causing factors Engine Cranks But Will Not Start Engine Will Not Crank e Battery connected backwards e Blown fuse e Carburetor solenoid malfunction e Choke not closing e Clogged fuel line or fuel filter e Diode in wiring harness failed in open circuit mode e DSAI or DSAM malfunction e Empty fuel tank e Faulty electronic control unit e Faulty ignition coil s e Faulty spark plug s e Fuel pump malfunction vacuum hose clogged or leaking e Fuel shut off valve closed e gnition module s faulty or improperly gapped e Insufficient voltage to electronic control unit e Interlock switch is engaged or faulty e Key switch or kill switch in OFF position e Low oil level e 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 Battery is discharged e Faulty electric starter or solenoid e Faulty key switch or ignition switch e Interlock switch is engaged or faulty e Loose wires or connections that intermittently ground ignition kill circuit e Pawls not engaging in drive cup e Seized internal engine components Engine Runs But Misses e Carburetor adjusted incorrectly e Engine overheated e Faulty spark plug s e Ignition module s faulty or improperly gapped e Incorrect crankshaft position sensor air gap e Interlock switch is engaged or faulty e Loose wires or
185. od 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 Details A Pressure Regulating B Pressure Regulating Spring Chamber C Diaphragm D Valve Seat E Fuel Chamber p to fuel ral G Return Port to tank H Inlet Port l Valve 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 24 690 01 Rev K Internal In Tank Regulator Remove screws securing retaining ring and regulator in base holder assembly Grasp and pull regulator out of base holder 5 Always use new O Rings a
186. odule Fastener 9 2 N m 81 in Ib Pulse Pump Bracket Fastener 2 1 N m 25 in Ib Pulse Pump Fastener to Bracket 7 3 N m 68 in Ib into new holes 6 2 N m 55 in Ib into used holes Governor Lever Nut 7 1 N m 63 in Ib 6 8 N m 60 in Ib Speed Control Assembly Assembled to Cylinder Heads 10 7 N m 95 in Ib Assembled to Blower Housing 2 8 N m 25 in Ib Ignition Spark Plug 27 N m 20 ft Ib Coil Fastener 10 2 N m 90 in Ib Ignition Module Fastener Torque 4 0 6 2 N m 35 55 in Ib Electronic Control Unit Screw 6 2 N m 55 in Ib Rectifier Regulator Ground Strap Ground Lead Fastener into backing 2 8 N m 25 in Ib into new holes plate 2 3 N m 20 in Ib into used holes Rectifier Regulator Ground Lead 5 6 N m 50 in Ib into new holes Fastener to Ground Lug Backing Plate 4 0 N m 35 in Ib into used holes Rectifier Regulator Fastener 1 4 N m 12 6 in Ib Values are in Metric units Values in parentheses are English equivalents gt Lubricate threads with engine oil prior to assembly 14 KohlerEngines com 24 690 01 Rev K TORQUE SPECIFICATIONS ECH630 ECH680 ECH730 ECH749 CH26 Specifications CH735 CH745 Ignition continued Crankshaft Position Sensor Earlier Design Bracket Crankshaft Position Sensor to Bracket Screw 11 3 N m 100 in Ib Crankshaft Position Sensor Bracket to Crankc
187. old Absolute Pressure Sensor MAP 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 temperature sensor from breather cover and cap or block sensor hole 2 Wipe sensor clean and allow it to reach room temperature 25 C 77 F 3 Unplug Black connector from ECU 4 With sensor still connected check temperature sensor circuit resistance between Black pin 10 and 14 terminals Value should be 9000 11000 O 5 Unplug sensor from wire harness and check sensor resistance separately across two pins Resistance value should again be 9000 11000 O a If resistance is out of specifications replace temperature sensor b If itis within specifications proceed to Step 6 6 Check circuits input ground from wire harness connector to sensor plug for continuity damage etc Connect one ohmmeter lead to Black pin 14 in wire harness connector as in step 4 Connect other lead to terminal 1 in sensor plug Continuity should be indicated Repeat test between Black pin 10 and terminal 2 in sensor plug Earlier engines have a separate intake air temperature IAT sensor located in throttle body and a manifold absolute pressure MAP sensor located in intake manifold Intake Air Temperature Sensor A non serviceable component Complete replacement is required if it is faulty Sensor and wiring harness ca
188. on 50 KohlerEngines com 24 690 01 Rev K EFI SYSTEM ECH 0230 Fuel Pump Module Circuit Low Voltage or Open 0232 Fuel Pump Module Circuit High Voltage 0336 Crankshaft Position Sensor Noisy Signal 0337 Crankshaft Position Sensor No Signal 0351 Cylinder 1 Ignition Coil Malfunction 0352 Cylinder 2 Ignition Coil Malfunction 0562 System Voltage Low 0563 System Voltage High 61 End of Code Transmission ECU continuously monitors engine operation against preset performance limits If operation is outside limits ECU activates MIL if equipped and stores a diagnostic code in its fault memory If component or system returns to proper function ECU will turn off MIL If MIL stays illuminated it warns customer a fault is currently happening and dealer service is required Upon receipt dealer technician can access fault code s to help determine what portion of system is malfunctioning Codes are accessed through key switch and displayed as blinks or flashes of MIL Access codes as follows 1 Check that battery voltage is above 11 volts 2 Start with key switch OFF 3 Turn key switch to ON and OFF then ON and OFF then ON leaving it on in third sequence Do not start engine Time between sequences must be less than 2 5 seconds 4 MIL will blink a series of times Number of times MIL blinks represents a number in blink code 5 Asequence of four digits make up a fault code The
189. onents 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 Heads secured with mounting studs nuts and washers 2 If all studs were left intact go to Step 6 If any studs were disturbed or removed install new studs as described in Step 3 Do not use reinstall any loosened or removed studs 3 Install new mounting stud s into crankcase a Thread and lock 2 mounting nuts together on smaller diameter threads b Thread opposite end of stud with preapplied locking compound into crankcase until specified height from crankcase surface is achieved When threading in studs use a steady tightening motion without interruption until proper height is obtained Otherwise frictional heat from engaging threads may cause locking compound to set up prematurely 128 KohlerEngines com Studs closest to lifters must have an exposed height of 75 mm 2 15 16 in Studs furthest from lifters must have an exposed height of 69 mm 2 3 4 in c Remove nuts and repeat procedure as required 4 Check dowel pins are in place and install a new cylinder head gasket part number facing up 5 Install cylinder head Match numbers on cylinder heads and crankcase Make sure head is flat on gasket and dowel pins 6 Lightly lubricate exposed upper threads of studs with engine oil Install a flat washer and hex nut onto each mo
190. ontrols ignition output and timing through transistorized control of primary current delivered to coils Based on input from crankshaft position sensor ECU determines correct firing point for speed at which engine is running At proper instant it interrupts flow of primary current in coil causing electromagnetic flux field to collapse Flux collapse induces an instantaneous high voltage in coil secondary which is strong enough to bridge gap on spark plug Each coil fires every other revolution EFI engines are equipped with either a 20 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 An electric fuel pump module and a lift pump two types are used to transfer fuel in EFI system Types of lift pumps are a pulse fuel pump a mechanical fuel pump or a low pressure electric fuel pump Pumping action is created by either oscillation of positive and negative pressures within crankcase through a hose or by direct lever pump actuation off rocker arm movement Pumping action causes diaphragm on inside of pump to pull fuel in on its downward stroke and to push it into fuel pump module on its upward stroke Internal check valves prevent fuel from going backward through pump Fuel pump module receives fuel from lift pump increases and regulates pressure for fuel injectors Fuel pump module is rated for a
191. op screw pivot throttle shaft and plate assembly into FULL THROTTLE position Insert a 1 52 mm 0 060 in feeler gauge between rear tang of throttle shaft plate and underside of manifold boss Use a locking pliers needle nose works best to temporarily clamp parts in this position b Onengines with a stop screw pivot throttle shaft and plate into FULL THROTTLE position so tang of throttle shaft plate is against end of high speed stop screw Temporarily clamp in this position 3 Rotate governor lever and shaft counterclockwise until it stops Use only enough pressure to hold it in that position 4 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 B 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 2 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 3 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 nut on clamping screw to 6 8
192. or Correct any observed problem reconnect sensor and perform step 5 again 7 When fault is corrected and engine starts clear fault codes following ECU Reset procedure Throttle Position Sensor TPS Earlier engines were built with a contacting brush type TPS Later engines are built with a contactless magnet type TPS Both designs have same three wires attached a 5 volt supply a ground and a signal wire However these designs are not interchangeable Follow proper testing information based on sensor type gt Throttle Between Resistance S Position Terminal Value Q Continuity Closed A amp C 1400 1800 Yes Full with Stop Pin A amp C 3200 4100 Yes Full without Stop Pin A amp C 4600 5200 Yes Any A amp B 3000 7000 Yes 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 Write this number down for reference later Disconnect Black connector from ECU but leave TPS mounted to throttle body a Use an ohmmeter and connect red positive ohmmeter lead to Black pin 12 terminal and black negative ohmmeter lead to Black pin 10 terminal to test b Hold throttle closed and check resistance It should be 1400 1800 Q Le
193. or TPS Code 23 Engine Control Unit ECU Code 31 Oxygen Sensor shorted Code 34 Fuel System permanent adaptation at limit Code 42 Engine Oil Temperature Sensor Code 43 TPS Auto Learn Initialization Function Below Min Limit 32 Pin MSE 1 1 Plastic Cased ECU only Code 44 TPS Auto Learn Initialization Function Above Max Limit 32 Pin MSE 1 1 Plastic Cased ECU only KohlerEngines com 89 EFI SYSTEM BOSCH e Code 51 Injector 1 32 Pin MSE 1 1 Plastic Cased ECU only e Code 52 Injector 2 32 Pin MSE 1 1 Plastic Cased ECU only e Code 55 MIL Light 32 Pin MSE 1 1 Plastic Cased ECU only e Code 56 Pump Relay 32 Pin MSE 1 1 Plastic Cased ECU only e MIL circuit grounded between light and ECU 35 Pin MA 1 7 Metal Cased ECU Pin circuit 31 24 Pin MSE 1 0 Plastic Cased ECU Pin circuit 19 32 Pin MSE 1 1 Plastic Cased ECU Pin circuit 29 e ECU 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 35 Pin MA 1 7 Metal Cased ECU Pin circuits 3 and 21 24 Pin MSE 1 0 Plastic Cased ECU Pin circuits 9 and 10 32 Pin MSE 1 1 Plastic Cased ECU Pin circuits 9 and 10 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
194. p dipstick and tighten securely Connect Spark Plug Leads Connect leads to spark plugs Prepare Engine for Operation ECH EFI NOTE If ECU throttle body TPS or fuel pump module were replaced an ECU Reset and TPS Learn is required Refer to Electrical System for ECU Reset and TPS Learn procedure Engine is now completely reassembled Before starting or operating engine be sure to do following 1 Make sure all hardware is tightened securely 2 Make sure oil drain plugs Oil Sentry pressure switch and a new oil filter are installed 3 Verify crankcase has been filled with correct amount weight and type of oil Refer to oil recommendations and procedures in Maintenance Specifications and Lubrication System 4 Adjust idle speed adjusting screw as necessary Refer to Fuel System 5 Turn on fuel supply KohlerEngines com 137 Reassembly Sensitivity Adjustment A Governor Lever B Hole 1 C Hole 2 D Hole 3 E Hole 4 Governor sensitivity is adjusted by repositioning governor spring in holes of governor lever If speed surging occurs with a change in engine load governor is set too sensitive If a big drop in speed occurs when normal load is applied governor should be set for greater sensitivity Adjust as follows 1 To increase sensitivity move spring closer to governor lever pivot point 2 To decrease sensitivity move spring away from governor lever pi
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196. perties of engine oil Check closure plate crankcase cylinder heads to be certain all old sealing material has been removed Use gasket remover lacquer thinner or paint remover to remove any remaining traces Clean surfaces with isopropyl alcohol acetone lacquer thinner or electrical contact cleaner 122 KohlerEngines com 24 690 01 Rev K Reassembly NOTE Proper orientation of piston connecting rod Install Flywheel End Oilseal assemblies inside engine is extremely important Oil Seal Detail Improper orientation can cause extensive wear or damage Be certain pistons and connecting rods are assembled exactly as shown NOTE 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 If piston rings were removed see Disassembly Inspection and Service procedure to install rings 2 Lubricate cylinder bore piston and piston rings with engine oil Compress rings of cylinder 1 piston using a piston ring compressor 3 Make sure FLY stamping on piston is facing towards flywheel side of engine Use a hammer with a rubber grip and gently tap piston into cylinder Be careful oil 1 ring rails do not spring free between bottom of ring A 45 mm 0 177 in B Oil Seal compressor and top of cylinder 4 Install inner rod cap to connecting rod using screws Torque in increments to 11 6 N m 103 in
197. 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 colored dye stripe if contained is to left of end gap 3 Top compression ring top groove Install top ring using a piston ring expander Make sure identification mark is up or colored dye stripe if contained is to left of end gap 24 690 01 Rev K Connecting Rods Offset stepped cap connecting rods are usedin all these engines Inspection and Service Check bearing area big end for excessive wear score marks running and side clearances refer to Specifications 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 0 25 mm 0 010 in undersized rod can be identified by drilled hole located in lower end of rod shank Always refer to appropriate parts information to ensure correct replacements are used Remove Crankshaft Carefully pull crankshaft from crankcase Inspection and Service Crankshaft Components and Details A Self Tapping Screw B Flat Washer C Plug D Crankshaft Fillet Must Blend Smoothly with Bearing Journal Surface High Point from Fillet Intersec
198. pproved 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 Typical electronic fuel injection EFI system and related components include Fuel pump module and lift pump Fuel filter High pressure fuel line Fuel line s Fuel injectors Throttle body intake manifold Electronic control unit ECU Ignition coils Engine oil temperature sensor Throttle position sensor TPS Earlier engines have a contacting brushes TPS Later engines have a contactless magnetic TPS Crankshaft position sensor Oxygen sensor Earlier engines have a separate manifold absolute pressure sensor MAP and an intake air temperature IAT sensor located in throttle body e Later engines have a combined temperature manifold absolute pressure TMAP sensor e Malfunction indicator light MIL optional e Wire harness assembly amp affiliated wiring FUEL RECOMMENDATIONS Refer to Maintenance FUEL LINE Low permeation fuel line must be installed on all Kohler 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 provi
199. rankshaft position sensor circuit problem pin circuits Black 4 and Black 13 e Crankshaft position sensor toothed wheel air gap e Toothed wheel e Flywheel key sheared e ECU Diagnostic Aid 5 FUEL PUMP fuel pump not turning on Condition e Main fuse e Fuel pump circuit problem pin circuits Black 9 and Grey 17 e Fuel pump module 24 690 01 Rev K EFI SYSTEM ECH Diagnostic Aid 6 IGNITION SYSTEM no spark Condition e Spark plug e Plug wire e Coil e Coil circuit s pin circuits Grey 10 and Black 1 e ECU grounds e ECU e Vehicle safety interlocks ground signal on safety wire Diagnostic Aid 7 FUEL SYSTEM ELECTRICAL no fuel delivery Condition e No fuel e Air in high pressure fuel line e Fuel valve shut OFF e Fuel filter line plugged e Injector circuit s pin circuits Black 5 and Black 6 e Injector e ECU grounds e ECU e Lift pump not working Diagnostic Aid 8 FUEL SYSTEM fuel pressure Low Fuel Pressure Condition e Low fuel e Fuel filter plugged e Fuel supply line plugged e Lift fuel pump insufficient fuel supply e Fuel pump lift or module internally plugged e Pressure regulator not functioning properly inside fuel pump module Diagnostic Aid 9 BASIC ENGINE cranks but will not run Condition e Refer to basic engine troubleshooting charts within Troubleshooting KohlerEngines com 57 EFI SYSTEM ECH EFI Diagnostic Flow Diagram START OF TEST PROCEED TO
200. rature greater than 80 C 176 F to properly adapt These adaptive values are maintained as long as ECU is not reset During certain operating periods 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 a
201. re 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 24 690 01 Rev K Install Closure Plate Assembly Reassembly Closure Plate Fastener Torgue Seguence A RTV Must Be All Around O ring Groove RTV sealant is used as a gasket between closure plate and crankcase Refer to Tools and Aids for a listing of approved sealants Always use fresh sealant Using outdated sealant can result in leakage 1 Be sure sealing surfaces have been cleaned and prepared as described at beginning of Disassembly Inspection and Service Install a new O ring in closure plate 2 Checkto make sure there are no nicks or burrs on sealing surfaces of closure plate or crankcase 3 Applya 1 5 mm 1 16 in bead of sealant to sealing surface of closure plate Verify O ring is present See sealant pattern 4 Make sure end of governor cross shaft is lying against bottom of cylinder 1 inside crankcase 5 Install closure plate to crankcase Carefully seat camshaft and crankshaft into their mating bearings Rotate crankshaft slightly to help engage oil pump and governor gear meshes 6 Install screws securing closure plate to crankcase Torque fasteners in sequence shown to 25 6 N m 227 in Ib One mo
202. re is a one 1 second pause between blinks of a fault code There is a three 3 second pause between separate fault codes After fault code s are blinked a two digit 61 is blinked to indicate program has completed 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 by following ECU Reset and TPS Learn Procedures Diagnostic Fault Code Summary lists fault codes and what they correspond to Diagnostic Code Summary is a list of individual codes with an explanation of what triggers them what symptoms might be expected and probable causes A MIL may not be provided with engine If equipment manufacturer has not added a MIL to equipment one can be added easily for quick diagnostics Main engine to vehicle connection will have a tan wire which is ground for MIL Either incandescent or LED type bulbs can be used for MIL as long as they do not draw more than 0 1 amps Bulb needs to be rated at 1 4 Watts or less or needs to have a total resistance of 140 O or more LEDs typically draw less than 0 03 amps Attach 12 volts to positive terminal of bulb and attach ground terminal of bulb to tan wire Diagnostic Code Summary Code 0031 Component Oxygen Sensor Heater Fault
203. ring closure plate to crankcase 2 Locate splitting tabs cast into perimeter of closure plate Insert drive end of a 1 2 in breaker bar between splitting tab and crankcase and turn it to loosen seal Do not pry on sealing surfaces as this can cause leaks Inspection Inspect oil seal in closure plate and remove it if it is worn or damaged Refer to Install Closure Plate Oil Seal in Reassembly for new oil seal installation Inspect main bearing surface for wear or damage refer to Specifications Replace closure plate assembly if required Governor Gear Assembly Governor Shaft Press Depth Details 114 KohlerEngines com A Gear Shaft B 19 40 mm 0 7638 in C 34 0 mm 1 3386 in 33 5 mm 1 3189 in Governor gear assembly is located inside closure plate If service is required continue with Inspection Disassembly and Reassembly 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 go
204. rive End Cap l Screw J Plunger K Spring L Lever M Plate N Plug O Solenoid P Frame and Field Q Brush Holder R Nut S Commutator End T Screw Plate U Bolt When power is applied to starter armature rotates As armature rotates drive pinion moves out on drive shaft splines and into mesh with flywheel ring gear When pinion reaches end of drive shaft it rotates flywheel and cranks engine When engine starts flywheel rotates faster than starter armature and drive pinion This moves drive pinion out of mesh with ring gear and into retracted position When power is removed from starter armature stops rotating and drive pinion is held in retracted position by anti drift spring 100 KohlerEngines com Starter Disassembly NOTE Do not reuse old retainer NOTE Do not soak armature or use solvent when cleaning Wipe clean using a soft cloth or use compressed air 1 Remove nut and disconnect positive brush lead bracket from solenoid terminal 2 Remove screws securing solenoid to starter 3 Remove retaining ring from armature shaft using either a retaining ring pliers or snap ring removal tool as described in Steps 4 and 5 Do not reuse old retainer 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 rubber gro
205. rom 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 Wiring harness used in EFI system connects 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 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
206. rovides excellent anti seize capabilities and no additional anti seize is needed If sensor is removed from engine and reinstalled anti seize compound should be reapplied Use an oxygen sensor safe type anti seize compound It should be applied according to directions on label KohlerEngines com 24 690 01 Rev K Troublshooting Oxygen Sensor O EFI SYSTEM ECH Condition Possible Cause Conclusion Low voltage output Shorted sensor or sensor circuit Shorted lead wire Wiring shorted to ground Replace sensor or repair wiring Contamination of air reference Remove source of external contamination protect air reference area Air leak at sensor or gasket sensor upper shield damage Use recommended torque at installation replace gasket or sensor Revise application exhaust Shield sensor from damage High voltage output Silica poisoning Replace sensor Contaminated gasoline Use high quality fuel Engine problem misfire Correct cause of misfire Excessive rich air fuel ratio Check for high fuel pressure Leaking injector Liquid fuel in vent line Wiring shorted to voltage Repair wiring Open circuit no activity from sensor Broken element Sensor dropped Hard blow to engine or exhaust system Defective sensor Thermal shock Replace sensor Slow time response Open heater circuit Improper handling Carbon deposits
207. rts 24 690 01 Rev K KohlerEngines com 27 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 with tester can be used if PTO end of crankshaft is accessible Lock holding tool onto crankshaft Install a 3 8 in breaker bar
208. s 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 fuel 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 KohlerEngines com 61 EFI SYSTEM BOSCH 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 pu
209. sed part is good and may be an inadeguate ground lead connection Make certain connection location is clean and clamp is secure Other lights come on Troubleshooting Guide NOTE Aflashing LOW light can also occur as a result of Rectifier regulator is faulty and should not be used 20 25 Amp Battery Charging 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 Conclusion Charging system is OK and battery was fully charged Test stator and rectifier regulator steps 2 and 3 Condition Charge rate increases when load is applied Charge rate does not increase when load is applied 2 Remove connector from rectifier regulator With engine running at 3600 RP
210. sembly to throttle body 2 Remove screws securing air cleaner assembly to air cleaner bracket and remove air cleaner assembly Low Profile Air Cleaner Optional 1 Loosen retaining knob and remove cover 2 Remove wing nut from element cover 3 Remove element cover air cleaner element with precleaner and stud seal 4 Remove nuts 5 Remove screws securing base and then remove base Remove Throttle Control Panel 1 Disconnect throttle control cable 2 Remove screws securing throttle control panel and remove panel from blower housing 24 690 01 Rev K External Governor Control ECH EFI Disassembly Inspection and Service X Speed Control Cable Clamp Throttle Actuator A Bracket B C Screw Lever bottom E Spring Washer F Throne poe Lever G Flat Washer Nut l Return Spring Remove External Governor Controls 1 Disconnect governor spring attaching governor lever to throttle actuator lever 2 Disconnect throttle linkage spring Remove throttle linkage bushing and throttle linkage from governor lever 3 Loosen nut and remove governor lever from cross shaft 24 690 01 Rev K KohlerEngines com 105 Disassembly Inspection and Service A WARNING Gasoline is extremely flammable and its vapors can f explode if ignited Store gasoline only in approved Suis Fuel can caus
211. silicone compounds fuel injector cleaners etc Use only those products indicated as O2 Sensor Safe 32 KohlerEngines com Fuel injectors mount into intake manifold and high pressure fuel line 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 high pressure fuel line and holds it in place O rings and retaining clip must be replaced any time fuel injector is separated from its normal mounting position When key switch is on fuel pump module will pressurize high pressure fuel line to 39 psi 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 high pressure fuel line 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 Injectors have sequential fueling that open and close once every other crankshaft revolution 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 Time injector is open milliseconds may vary in duration depending on speed and load requirements of engine A high voltage solid state battery ignition system is used with EFI system ECU c
212. solenoid shift starters 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 Or Engine Make sure clutch or transmission is disengaged or placed in neutral This is especially important on equipment with 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 24 690 01 Rev K KohlerEngines com 99 Starter System SOLENOID SHIFT ELECTRIC STARTERS Solenoid Shift Starter Components A Tube B Washer C Armature D Drive E Stop F Retaining Ring G Collar H D
213. sor push electrical connector onto IAT sensor making sure a good connection is made by listening for a click 5 Connect breather hose to throttle body using a pliers to compress spring clamp Route hose around throttle body and connect to breather cover using a spring clamp KohlerEngines com 133 Reassembly 6 Connect 5 32 1 D vent hose from fuel pump module to throttle body 7 Push electrical connector onto throttle position sensor making sure a good connection is made A WARNING Ww burns running Explosive Fuel can cause fires and severe Do not fill fuel tank while engine is hot or 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 Fuel Pump ECH EFI Outlet to Fuel Pump A Pulse Pump Inlet Hose Module Pulse Hose E Electrical Connector Fuel Pump Module Fuel Naag dra DRE in l Oetiker Clamp Purge Port Vent Fitting NOTE Some applications may have 2 in line fuel filters In those applications connect in line 51 75 micron mesh fuel filter and hose to inlet barb of lift fuel pump and secure with a spring clamp In line 10 micron EFI paper fuel filter and hose must be connected to outlet b
214. spark plug boot terminal and B primary terminal Secondary resistance should be 6400 7800 O d If secondary resistance is not within specified range coil is faulty and needs to be replaced FUEL COMPONENTS A 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 Fuel Pump Module FPM Fuel pump module is not serviceable and must be replaced if determined to be faulty If a fuel pump problem is suspected make certain pump is being activated 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 may be conducted 1 Relieve fuel pressure at fuel pump module Fuel pump module may need to be loosened or pulled away from engine Disconnect fuel coupler from fuel pump module and insert pressure test jumper from Kohler EFI Service Kit between high pressure fuel line and fuel pump module 2 Connect black hose of Pressure Tester Route clear hose into a portable gasol
215. ssure fuel line is mounted to intake manifold No specific servicing is required unless operating conditions indicate that it needs replacement Thoroughly clean area around all joints and relieve any pressure before starting any disassembly Detach by removing two mounting screws wire ties and injector retaining clips Purge Port and Vent Hose Assembly No specific servicing is required for vent hose assembly or purge port unless operating conditions indicate replacement is required All components are serviced individually Abrasion sleeves on hoses should be reused or replaced when servicing vent hoses Please note vent hose routing and replicate after service or component replacement to prevent pinching or abrasion of vent hoses Only Kohler replacement parts can be used because fitting is specific to system and must be maintained Visit KohlerEngines com for recommended Kohler replacement parts Throttle Body Intake Manifold Assembly NOTE ECU Reset is required if throttle body is replaced Throttle body is serviced as an assembly with throttle shaft TPS throttle plate and idle speed adjusting screw installed Throttle shaft rotates on needle bearings non serviceable capped with seals to prevent air leaks TROUBLESHOOTING Troubleshooting Guide Condition Possible Cause Fuel pump not running Faulty spark plugs Old stale fuel Incorrect fuel pressure Crankshaft position sensor loose or faulty Engine Starts Hard TPS set
216. st 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 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 118 KohlerEngines com 80 mm bore engines Top compression ring end gap is 0 100 0 279 mm 0 0039 0 0110 in Middle compression ring end gap is 1 400 1 679 mm 0 0551 0 0661 in 83 mm bore engines Top compression ring end gap is 0 189 0 277 mm 0 0074 0 0109 in Middle compression ring end gap is 1 519 1 797 mm 0 0598 0 0708 in 5 After installing new compression top and middle rings on piston make sure ring to groove side clearance is 0 030 0 070 mm 0 001 0 0026 in If side clearance is greater than specified a new piston must be used Install New Piston Rings Piston Ring Orientation A Top Oil Ring Rail B Bottom Oil Ring Rail Gap Gap C Intermediate Ring D Oil Ring Expander Gap Gap Top Ring Gap FLY Stamp 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
217. stall 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 and separate solenoid from starter for testing To test solenoid pull in coil plunger Actuation 1 Use a 12 volt power supply and 2 test leads 2 Connect 1 lead to flat spade S start terminal on solenoid Momentarily connect other lead to lower large post terminal When connection is made solenoid should energize audible click and plunger retract Repeat test several times Continuity 1 Use an ohmmeter set to audible or Rx2K scale and connect 2 ohmmeter leads to 2 large post terminals 2 Perform solenoid pull in coil plunger actuation test and check for continuity Ohmmeter should indicate continuity Repeat test several times To test solenoid hold in coil Function 1 Connecta 12 volt test lead to flat spade S start terminal on solenoid and other lead to body or mounting surface of soleno
218. stic housing that is press fit to end of throttle shaft This generally does not need replacement If replacement is required can be replaced as follows 1 Remove sensor from throttle body exposing round magnet assembly 2 Apair of flat blade screw drivers or a spanner tool can be used to pry this off shaft Caution should be used to avoid damage to machined flat surface that sensor seals against Also make sure throttle blade is in full open position to avoid driving throttle blade into throttle bore causing damage to blade and or bore 3 When replacing magnet assembly alignment is critical There is a D shaped drive feature on end of shaft and a matching pocket in magnet assembly On outer diameter of magnet assembly is a notch that aligns with center of flat feature of D Align this notch and flat of D feature in shaft and preassemble parts 4 With throttle blade in full open position WOT press magnet assembly fully on to throttle shaft Full insertion can be checked by measuring height from throttle body sensor mounting face to end of magnet assembly This should be no more than 8 6 mm 0 338 in Installation process requires significant force so take care that all parts are aligned Tapping magnet assembly on can fracture damage brittle magnet within assembly and throttle body assembly and is NOT RECOMMENDED A Magnet Assembly B KohlerEngines com 41 EFI SYSTEM ECH Engine Oil Temperature Sensor Manif
219. storted If cracked or badly warped cylinder head should be replaced 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 Lapping Valves NOTE Exhaust valves that are black in color cannot be ground and do not require lapping 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 Valve Stem Seal These engines use valve stem seals on intake and exhaust 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 Flywheel Components A Flywheel Fan B Flywheel C Stator D Backing Plate Remove Fan and Flywh
220. 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 101 Starter System 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 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 11 Install end cap onto armature and frame aligning thin raised rib in end cap with corresponding slot in grommet of positive brush lead 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 in
221. t fault code and assist with troubleshooting and repair 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 With sensor connected check oil temperature sensor circuit resistance Value should be 2375 2625 O See chart on pages 35 Pin MA 1 7 Metal Cased ECU Check between 14 and 27 pin terminals 24 Pin MSE 1 0 Plastic Cased ECU Check between 6 and 4 pin terminals 32 Pin MSE 1 1 Plastic Cased ECU Check between 6 and 4 pin terminals KohlerEngines com 65 EFI SYSTEM BOSCH 5 Unplug sensor connector and check sensor resistance separately Resistance value should again be 2375 2625 a If resistance is out of specifications replace temperature sensor b If itis 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 35 Pin MA 1 7 Metal Cased ECU Pin circuits 14 and 27 24 Pin MSE 1 0 Plastic Cased ECU Pin circuits 6 and 4 32 Pin MSE 1 1 Plastic Cased ECU Pin circuits 6 and 4 Cu
222. tance between sensor lead and sensor case It should be less than 2 0 KO a 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 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 MO 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 66 KohlerEngines com 24 690 01 Rev K 5 With oxygen sensor disconnected and engine not running disconnect main harness connector from ECU and set meter to Rx1 scale Check circuit continuity as follows 24 Pin MSE 1 0 Plastic Cased ECU Check for continuity from pin 15 of ECU connector see page to shell of oxygen sensor and from pin 11 to sensor connector terminal of main harness Both tests should indicate continuity 32 Pin MSE 1 1 Plastic Cased ECU Check for continuity from pin 19 of ECU connector see page 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 path back through exhaust system engine and mounting sensor is grounded
223. taway of Oxygen Sensor DUO snnm L6 4 e qe 4 4 c eoe t e P 30909 A ne ENNEN a e e le e ece eee e Taa a 660 KA aa Tea Taa Ta Tee Rea aa ee SES A Connection Cable B Disc Spring Ceramic Support C Tube D Protective Sleeve E F Contact Element Sensor Housing G Active Ceramic H Sensor Protective Tube NOTE All tests should be conducted with a good guality 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 not 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
224. ted to battery shorted to battery Condition Engine will run very poorly with only one Condition Engine will run very poorly with only one cylinder functioning cylinder functioning Conclusion Injector Related Conclusion Injector Related e Injector coil shorted or opened e Injector coil shorted or opened 8 Engine Wiring Harness Related Engine Wiring diis SEE e Broken or shorted wire in harness e Broken or shorted wire in harness ECU pin 15 to injector pin 2 ECU pin ECU pin 14 to injector pin 2 ECU 28 to fuel pump relay pin 86 Note pin 28 to fuel pump relay pin 86 after key off then key on code 56 Note after key off then key on code would be set also Fuel pump relay pin 56 would be set also Fuel pump 87 to injector pin 1 relay pin 87 to injector pin 1 e Opened main fuse F1 e Open main fuse F1 Fuel Pump Relay Related Fuel Pump Relay Related e Bad fuel pump relay e Bad fuel pump relay Primary side functional but pin 30 Primary side functional but pin 30 to to pin 87 remains open pin 87 remains open Primary side Primary side pin 85 to pin 86 is pin 85 to pin 86 is either open or open or shorted during engine shorted during engine operation operation Note after key off then Note after key off then key on code key on code 56 would be set also 56 would be set also ECU Related Bou Related 04 e Circuit controlling injector 2 damaged e Circuit controlling injector 1 damaged e Circuit controlling fuel pump
225. tem operation If TPS or ECU is changed or mounting position of TPS is altered appropriate TPS Learn Procedure must be performed to restore synchronization Any service to ECU TPS Throttle Body including idle speed increase over 300 RPM or fuel pump module replacement should include ECU Reset This will clear all trouble codes all closed loop learned offsets all max values and all timers besides permanent hour meter This system will NOT reset when battery is disconnected ECU Reset Procedure 1 Turn key ignition OFF 2 Install Red wire jumper from Kohler EFI service kit on to service port connect white wire to black wire in 4 way diagnostic port 3 Turn key ignition ON then OFF and count 10 seconds 4 Turn key ignition ON then OFF and count to 10 seconds a second time 5 Remove Red wire jumper Turn key ignition ON then OFF and count to 10 seconds a third time ECU is reset A TPS Learn Procedure must be performed after ECU Reset 24 690 01 Rev K EFI SYSTEM ECH TPS Learn Procedure 1 Turm idle screw clockwise one full turn prior to key ignition ON after ECU Reset 2 Start engine run at low idle until engine is warm 3 Idle speed must be above 1500 RPM If below 1500 RPM turn idle screw up to 1700 RPM and then shut down engine and perform ECU Reset again 4 Adjust idle speed down to 1500 RPM Allow engine to dwell at 1500 RPM for about 3 seconds 5 After this adjust idle speed to fi
226. through its shell b If continuity is indicated go to step 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 ale 5 Disconnect oxygen sensor connector from wiring harness Loosen and remove oxygen sensor from exhaust manifold muffler assembly 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 Reconnect lead to wiring harness connector Make sure it can not contact hot surfaces moving parts etc Test run engine A malfunctioning relay can result in starting or operating difficulties Relay and related wiring can be tested as follows T 2 24 690 01 Rev K Disconnect relay connector plug from relay Connect black lead of VOA meter to a chassis ground location Connect red lead to 86 terminal in relay connector Set meter to test resistance Rx1 Turn ignition switch from OFF to O
227. tion L can send a damaging voltage spike through 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 before performing any welding on equipment KohlerEngines com 33 EFI SYSTEM ECH ELECTRICAL COMPONENTS Electronic Control Unit ECU Grey Connector Side Pinout of ECU Black Connector Side Pin Function 1 Ignition Coil 1 Ground Battery Ground Diagnostic Communication Line Speed Sensor input Fuel Injector Output 1 Ground Fuel Injector Output 2 Ground Oxygen Sensor Heater CO Oo O1 4 C5 h2 Intake Air Temperature IAT sensor or TMAP sensor input 9 Fuel Pump Ground 10 Ground for TPS IAT and MAP sensors or TMAP sensor O2 and Oil sensors 11 MAP sensor or TMAP sensor input 12 Throttle Position Sensor TPS input 13 Speed Sensor Ground 14 Oil Temperature Sensor input Pin 2 Description
228. tions 45 Minimum IJO T m This Fillet Area Must Be Completely Smooth 24 690 01 Rev K Disassembly Inspection and Service NOTE If crankpin is reground visually check to ensure fillet blends smoothly with crankpin surface NOTE To prevent repeat failures camshaft and crankshaft should always be replaced as a set 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 Some engines have bearing inserts in crankshaft bore of closure plate and or crankcase Do not replace bearings unless they show signs of damage or are out of running clearance specifications If crankshaft turns easily and noiselessly and there is no evidence of scoring grooving etc on races or bearing surfaces bearings can be reused Inspect crankshaft keyways If they are worn or chipped replacement of crankshaft will be necessary Inspect crankpin for score marks or metallic pickup Slight score marks can be cleaned with crocus cloth soaked in oil If wear limits as stated in Specifications and Tolerances are exceeded it will be necessary to either replace crankshaft or 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 o
229. to 16 0 N m 142 in Ib 3 Connect leads to solenoid ECU ECH EFI Install Electronic Control Unit ECU iz Electronic Control A Unit ECU B ECU Bracket C Starter NOTE ECU pins should be coated with a thin layer of electrical grease to prevent fretting and corrosion and may need to be reapplied if ECU is being reused 24 690 01 Rev K Reassembly 1 Install ECU to ECU bracket using screws Torque M5 screws to 6 2 N m 55 in Ib into new holes or 4 0 N m 35 in Ib into used holes 2 Connect Black and Grey electrical connectors Connectors and ECU are keyed in such a way so they cannot be installed incorrectly Install Throttle Body ECH EFI Throttle Body Components ECH EFI Intake Air C Temperature IAT Sensor NOTE Ensure all parts are clean undamaged and free of debris and make sure electrical connector has seal in place NOTE Earlier engines have separate IAT and MAP sensors 1 Install a new throttle body O ring prior to installation Make sure all holes align and are open 2 Install throttle body throttle position sensor intake air temperature IAT sensor earlier engines only throttle linkage spring and bushing as an assembly 3 Install air cleaner bracket models with heavy duty air cleaner only to valve covers Torque screws to 9 9 N m 88 in Ib 4 On earlier engines with separate intake air temperature IAT and MAP sen
230. ttent 5 volt source from ECU pin Black 16 e ECU to harness connection problem 24 690 01 Rev K KohlerEngines com 53 EFI SYSTEM ECH Code 0171 Code 0172 Component Fuel System Component Fuel System Fault Maximum adaptation limit exceeded Fault Minimum adaptation limit exceeded Condition Fuel inlet screen filter plugged low Condition Too high pressure at high pressure fuel pressure at high pressure fuel line TPS line TPS malfunction shorted malfunction shorted connection faulty connection faulty sensor or fuel pump sensor low fuel or wrong fuel type module failure Conclusion Oxygen Sensor Related Conclusion Oxygen Sensor Related e Corrosion or poor connection e Sensor connector or wiring e Sensor contaminated or damaged e Sensor contaminated or damaged e Air leak into exhaust e Poor ground path e Poor ground path e Pin circuit wiring or connectors e Pin circuit wiring or connectors ECU Black pin 10 or 17 ECU Black pin 10 or Black pin 17 TPS Sensor Related TPS Sensor Related e Throttle plate position incorrect during e Throttle plate position incorrect during Learn procedure Learn procedure e TPS problem or malfunction e TPS problem or malfunction Engine Wiring Harness Related Engine Wiring Harness Related e Difference in voltage between sensed e Difference in voltage between sensed voltage and actual sensor voltage voltage and actual sensor
231. ttle lever and manifold boss to firmly hold throttle against idle stop On some EFI engines there is a dampening spring on end of idle speed screw Dampening spring if used should be fully compressed and tab on throttle lever in direct contact with speed screw Adjust idle speed to 1500 RPM using a tachometer 6 Shut off engine 24 690 01 Rev K 10 11 Locate service connector plug in wiring harness 35 Pin MA 1 7 Metal Cased ECU Connect a jumper wire from TPS initialization pin 8 gray wire to ground pin black wire or use jumper plug with red jumper wire 24 Pin MSE 1 0 Plastic Cased ECU 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 Hold throttle against idle speed stop screw turn ignition switch to ON position do not start engine and observe Malfunction Indicator Light MIL a Light should blink on off quickly for approximately 3 seconds and then go off and stay off indicating initialization procedure has been successful b If light stays on or blinking ceases prematurely procedure was unsuccessful and must be repeated Possible causes for unsuccessful learning may be 1 Movement occurred in either TPS or throttle shaft during procedure 2 Crankshaft movement rotation was detected by Speed sensor during procedure 3 Throttle plate position was out of learnable range recheck 150
232. ue hex nut to 7 1 N m 63 in Ib BOSCH EFI CH26 CH735 CH745 Refer to EFI SYSTEM BOSCH section for Initial Governor Adjustment procedure Install Muffler 1 Install port liners if equipped Install exhaust gaskets and muffler Install oxygen sensor torque to 50 1 N m 37 ft Ib and connect to wire harness 2 Install muffler and attaching hardware to muffler bracket Torque screws to 9 9 N m 88 in Ib 3 Install nuts to exhaust studs Torque nuts to 27 8 N m 246 in Ib 24 690 01 Rev K 1 Secure adapter to closure plate with oil filter nipple Torque oil filter nipple to 28 5 N m 21 ft Ib 2 Verify all fuel and vent hoses are routed properly and not pinched Install 2 screws to blower housing Torque screw between hoses to 2 3 N m 20 in Ib and outer screw to 2 8 N m 25 in Ib Install Oil Filter and Fill Crankcase with Oil NOTE If testing oil pressure after completing reassembly install oil pressure adapter instead of oil filter 1 Prefill a new oil filter following instructions 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 ca
233. ulty Engine temperature sensor faulty Faulty injectors Faulty spark plugs Insufficient fuel delivery Engine stalls or TPS offset incorrect idles roughly cold Or warm TPS faulty Faulty engine temperature sensor Faulty injectors Fuel injector s fuel filter fuel line or fuel pick up dirty restricted Dirty air cleaner Insufficient fuel pressure or fuel delivery Engine misses Vacuum intake air leak hesitates or stalls Improper governor setting adjustment or operation under load Speed sensor malfunction 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 WOT stop if so equipped 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
234. unting screws has a thread sealant patch This screw is typically installed in 10 hole shown Reapply pipe sealant with Teflon Loctite amp 5927 PST Thread Sealant or equivalent 24 690 01 Rev K Install Stator and Backing Plate 1 Apply pipe sealant with Teflon Loctite 592 PST Thread Sealant or equivalent to stator mounting holes Position stator aligning mounting holes so leads are at bottom towards crankcase Install and torque screws to 6 2 N m 55 in Ib into new holes or 4 0 N m 35 in Ib into used holes Route stator leads in crankcase channel then install backing plate Secure using 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 KohlerEngines com 125 Reassembly Install Flywheel W A cAUTION 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 Flywheel Components A Flywheel Fan B Flywheel C Stator D Backing Plate NOTE Before installing flywheel make sure crankshaft NOTE 1 Install woodruff key into keyway of crankshaft Make sure key is properly seated and parallel with shaft taper and flywheel hub are clean dry and completely free of
235. unting stud Torque hex nuts in 2 stages first to 16 9 N m 150 in Ib finally to 33 9 N m 300 in Ib Follow torque sequence Heads secured with screws 2 Install a new cylinder head gasket part number facing up 3 Install cylinder head and start screws 4 Torque screws in 2 stages first to 22 6 N m 200 in Ib finally to 41 8 N m 370 in Ib Follow torque sequence Install Push Rods and Rocker Arms NOTE Push rods should always be installed in same position as before disassembly 1 Note mark or tag identifying push rod as either intake or exhaust and cylinder 1 or 2 Dip ends of push rods in engine oil and install making sure each push rod ball seats in its hydraulic lifter socket 2 Apply grease to contact surfaces of rocker arms and rocker arm pivots Install rocker arms and rocker arm pivots on 1 cylinder head and start screws 3 Torque screws to 18 1 N m 160 in Ib Repeat for other rocker arm 4 Use a spanner wrench or rocker arm lifting tool see Tools and Aids to lift rocker arms and position push rods underneath 5 Repeat above steps for remaining cylinder Do not interchange parts from cylinder heads 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 Check Assembly Important Rotate crankshaft a minimum of 2 revolutions to check longblock assembly and ov
236. vernor gear assembly 3 Carefully inspect governor gear shaft and replace it only 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 24 690 01 Rev K Oil Pump Assembly Style A Disassembly Inspection and Service Oil Pump Assembly Style B Oil Pump Style A Torque Sequence Oil pump is mounted inside 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 Unhook locking clip and care fully pull it free from oil pump housing 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 Reassembly 1 Install oil pickup to oil pump body Lubricate O ring with oil and make sure it remains in groove as pickup is being installed 2 Install rotor 3 Install oil pump body to closure plat
237. vot point Testing Engine It is recommended engine be operated on a test stand or bench prior to installation in piece of equipment 1 Setengine up on a test stand Start engine inspect for leaks and check to make certain oil pressure 20 psi or more is present Run engine at idle for 2 3 minutes then 5 6 minutes more between idle and midrange 2 Adgjust idle speed screw located on throttle body as necessary Standard idle speed setting for EFI engines is 1500 RPM but certain applications might require a different setting 3 Adjust high speed stop as necessary located on control panel if so equipped Make sure maximum engine speed does not exceed 4200 RPM no load 138 KohlerEngines com 24 690 01 Rev K 24 690 01 Rev K KohlerEngines com 139 1P24 690 01 O 2015 by Kohler Co All rights reserved 6 50531 96541 7 140 KohlerEngines com 24 690 01 Rev K
238. ween terminals indicated A reading of 750 1000 should again be obtained T lf 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 Speed Sensor Circuit Corresponds To 3 Metal Cased ECU or 10 Plastic Cased ECU In Main Connector Corresponds To 21 Metal Cased ECU C or 9 Plastic Cased D ECU In Main Connector B Dual Aligning Rails Test Terminals KohlerEngines com 63 EFI SYSTEM BOSCH Throttle Position Sensor TPS Throttle Between Resistance beau Position Terminals Value O Continuity Closed 2 amp 3 800 1200 Yes Closed 1 amp 3 1800 3000 Yes Full 2 amp 3 1800 3000 Yes Full 1 amp 3 800 1200 Yes Any 1 amp 2 1600 2500 Yes A Throttle Valve Shaft B Resistor Track C Wiper Arm with D Electrical Wiper Connection The TPS is a sealed non serviceable assembly If diagnosis indicates a bad sensor complete replacement is necessary If a blink code indicates a problem with TPS it can be tested as follows 1 Counting number of turns back out idle speed adjusting screw counterclockwise unt
239. wiring harness are functioning 2 Check continuity in wire harness Ohms between Pin 3 at sensor connector and Black pin 11 connector at ECU should be near zero ohms If no continuity is measured or very high resistance replace wire harness 3 Check to make sure intake manifold is not loose and MAP sensor is not loose Loose parts would allow a vacuum leak making MAP sensor report misleading information to ECU a Tighten all hardware and perform an ECU Reset and a TPS Learn Procedure to see if MIL will display a fault with MAP sensor again If MIL finds a fault with MAP sensor replace it Later engines have a combined temperature manifold absolute pressure TMAP sensor located in intake manifold Temperature Manifold Absolute Pressure TMAP Sensor A sealed non serviceable integrated sensor that checks both intake air temperature and manifold absolute pressure Complete replacement is required if it is faulty Sensor and wiring harness can be checked as follows If a blink code indicates a problem with Intake Air Temperature TMAP Sensor Circuit P0112 or P0113 it can be tested as follows 1 Remove TMAP sensor from intake manifold 2 Allow it to reach room temperature 20 C 68 F 3 Unplug Black connector from ECU 4 With sensor still connected check temperature sensor circuit resistance between Black pin 10 and 8 pin terminals Value should be 1850 2450 O 5 Unplug sensor from wire harness and check s
240. with clean engine oil Push retaining clip onto fuel injector aligning clip Press fuel injector into fuel injector cap until retaining clip snaps into place Press fuel injector into bore in intake manifold and rotate to original position Install fuel injector cap screw into intake manifold and torque to 7 3 N m 65 in Ib Push electrical connector on fuel injector making sure a good connection is made Repeat steps 1 through 6 for other fuel injector 24 690 01 Rev K KohlerEngines com 129 Reassembly Install Manifold Absolute Pressure MAP Sensor or Temperature Manifold Absolute Pressure TMAP Sensor ECH EFI NOTE Ensure all parts are clean undamaged and free of debris and make sure electrical connector has seal in place 1 Lightly oil MAP or TMAP sensor O ring and push sensor into bore in intake manifold 2 Torque screw to 7 3 N m 65 in Ib 3 Push electrical connector on MAP or TMAP sensor making sure a good connection is made Install Crankshaft Position Sensor NOTE Ensure all parts are clean undamaged and free of debris and make sure electrical connectors have seal in place NOTE On engines with earlier design bracket an air gap must be set when installing Later design brackets require no adjustment 1 Install crankshaft position sensor and bracket assembly to crankcase posts 2 Onengines with earlier design bracket snug screws and check air gap of sensor with a feeler gau
241. y 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 Ignition Testing 1 Disconnect main harness connector from ECU 24 Pin MSE 1 0 Plastic Cased ECU Locate pins 22 and 23 in 24 pin connector See page 32 Pin MSE 1 1 Plastic Cased ECU Locate pins 30 and 31 in 32 pin connector See page 2 Disconnect connector from relay and locate terminal 87 in connector 3 Using an ohmmeter set on the Rx1 scale check resistance in circuits as follows 24 Pin MSE 1 0 Plastic Cased ECU Check between terminal 87 and pin 22 for coil 1 Repeat test between terminal 87 and pin 23 for coil 2 32 Pin MSE 1 1 Plastic Cased ECU Check between terminal 87 and pin 30 for coil 1 Repeat test between terminal 87 and pin 31 for coil 2 A reading of 1 8 4 0 O 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 the Rx1 scale to primary terminals Primary resistance should be 1 8 2 5 O KohlerEngines com 69 EFI SYSTEM BOSCH 3 Disconnect secondary lead f

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