manualshive.com logo in svg

Kohler Command PRO CH749, Service Manual

The Kohler Command PRO CH749 is a high-performance engine designed for heavy-duty applications. For convenient maintenance and troubleshooting, make sure to download the free Service Manual from manualshive.com. This comprehensive manual provides detailed instructions, diagrams, and tips to ensure optimal performance and longevity of your engine.

Share
Download
background image

1.8

Section 1
Safety and General Information

General Specifi cations¹

Power (@ 3600 RPM, exceeds Society of Automotive Engineers-Small Engine Test Code J1940.)
 ECH630 

.................................................................................................................................... 14.1 kW (19 HP)

 ECH650 

.................................................................................................................................... 15.7 kW (21 HP)

 ECH680 

.................................................................................................................................... 17.2 kW (23 HP)

 ECH730 

.................................................................................................................................... 18.6 kW (25 HP)

 ECH740 

.................................................................................................................................... 20.1 kW (27 HP)

 ECH749 

.................................................................................................................................... 21.6 kW (29 HP)

Bore
 ECH630,ECH650,ECH680 

.................................................................................................... 80 

mm (3.15 in.)

 ECH730,ECH740,ECH749..................................................................................................... 83 

mm (3.27 in.)

Stroke .............................................................................................................................................. 69 mm (2.72 in.)

Displacement
 ECH630,ECH650,ECH680 

.................................................................................................... 694 

cc (42.4 cu. in.)

 ECH730,ECH740,ECH749..................................................................................................... 747cc (45.6 cu. in.)

Compression Ratio
 ECH630,ECH650,ECH680..................................................................................................... 8.8:1
 ECH730,ECH740,ECH749..................................................................................................... 9.1:1

Dry Weight ..................................................................................................................................... 46 kg (102 lb.)

Oil Capacity (w/

fi

 lter) - approximate, determined by oil 

fi

 lter and oil cooler used ........... 1.9 L (2.0 U.S. qt.) 

Angle of Operation - Maximum (At Full Oil Level) All Directions ....................................... 25°

Blower Housing Screws (into cored aluminum hole or weld nut)

M5 Fasteners Torque ....................................................................................... 6.2 N·m (55 in. lb.) into new holes
 

 

4.0 N·m (35 in. lb.) into used holes

M6 Fasteners Torque ....................................................................................... 10.7 N·m (95 in. lb.) into new holes
 

 

7.3 N·m (65 in. lb.) into used holes

Blower Housing Screws (into extruded hole or sheet metal)

M5 Fasteners Torque ....................................................................................... 2.8 N·m (25 in. lb.) into new holes
 

 

2.3 N·m (20 in. lb.) into used holes

M6 Fasteners Torque ....................................................................................... 2.8 N·m (25 in. lb.) into new holes
 

 

2.3 N·m (20 in. lb.) into used holes

Recti

fi

 er-Regulator Ground Strap Fastener Torque ................................... 2.8 N·m (25 in. lb.) into new holes

 

 

2.3 N·m (20 in. lb.) into used holes

Blower Housing Screws

Recti

fi

 er-Regulator Fastener Torque ............................................................. 1.4 N·m (12.6 in. lb.)

¹Values are in Metric units. Values in parentheses are English equivalents. Lubricate threads with engine oil  
  prior to assembly.

Summary of Contents for Command PRO CH749

Page 1: ...SERVICE MANUAL ECH630 ECH749 HORIZONTAL CRANKSHAFT ...

Page 2: ......

Page 3: ...Troubleshooting Section 4 Air Cleaner and Air Intake System Section 5 Electronic Fuel Injection EFI System Section 6 Lubrication System Section 7 Electrical System and Components Section 8 Disassembly Section 9 Inspection and Reconditioning Section 10 Reassembly 2 1 4 5 3 9 10 6 7 8 ...

Page 4: ......

Page 5: ... starting can cause severe injury or death Before working on the engine or equipment disable the engine as follows 1 Disconnect the spark plug lead s 2 Disconnect negative battery cable from battery WARNING Rotating Parts can cause severe injury Stay away while engine is in operation Rotating Parts Keep hands feet hair and clothing away from all moving parts to prevent injury Never operate the eng...

Page 6: ...lvents can cause severe injury or death Use only in well ventilated areas away from ignition sources Flammable Solvents Carburetor cleaners and solvents are extremely flammable Keep sparks flames and other sources of ignition away from the area Follow the cleaner manufacturer s warnings and instructions on its proper and safe use Never use gasoline as a cleaning agent Figure 1 1 Engine Identificat...

Page 7: ...ergent oil of API American Petroleum Institute Service Class SJ or higher Select the viscosity based on the air temperature at the time of operation as shown in the following table F 20 0 20 32 40 60 50 80 100 C 30 20 10 0 10 20 30 40 5W 30 10W 30 Kohler 10W 30 SAE 30 Model No Electronic Fuel Injection EFI Command Engine Numerical Designation 630 650 680 730 740 749 Spec No ECH630 XXXX ECH650 XXXX...

Page 8: ...handle and helps eliminate spillage during refueling Do not use gasoline left over from the previous season to minimize gum deposits in your fuel system and to ensure easy starting Do not add oil to the gasoline Do not overfill the fuel tank Leave room for the fuel to expand Fuel Type For best results use only clean fresh unleaded gasoline with a pump sticker octane rating of 87 R M 2 or higher In...

Page 9: ...mpty 4 Remove the spark plugs and add one tablespoon of engine oil into each spark plug hole Install the spark plugs but do not connect the plug leads Crank the engine two or three revolutions 5 Disconnect the negative battery cable or use a battery minder trickle charger while the unit is in storage 6 Store the engine in a clean dry place Daily or Before Starting Engine Maintenance Required Frequ...

Page 10: ...0 3 626 184 20 7 252 17 53 0 690 Spark Plug Mounting Hole A Engine LIFT STRAP 2X OIL DRAIN PLUG 3 8 NPT IN 89 00 3 504 MOUNTING HOLE A 432 61 17 032 471 44 18 560 210 40 8 284 52 40 20 063 OIL FILL LOCATION OIL DIPSTICK 622 63 24 513 1 4 IN SQ KEYWAY 85 50 3 366 28 56 Ø 1 125 7 16 20 UNF 2B IN 38 10 1 500 155 58 6 125 152 08 5 987 OIL FILTER 97 38 3 834 52 75 2 077 OIL FILTER 104 00 4 094 89 00 3 ...

Page 11: ... 050 5 750 ENGINE MTG SURFACE SOLENOID SHIFT STARTER MOUNTING HOLE A M8 X 1 25 20 5 DEEP 2 HOLES MUFFLER MTG BOSSES 308 17 12 133 M8 X 1 25 4 STUDS 283 58 11 164 50 00 1 969 EXHAUST PORT 1 50 00 1 969 EXHAUST PORT 2 LIFT STRAP 75 35 2 966 65 00 2 559 122 10 4 807 173 68 6 838 30 334 78 13 180 50 00 1 969 SPARK PLUG 32 00 1 260 EXHAUST PORT 2 12 00 0 472 EXHAUST PORT 1 OIL DIPSTICK 432 61 17 032 EN...

Page 12: ... 2 0 U S qt Angle of Operation Maximum At Full Oil Level All Directions 25 Blower Housing Screws into cored aluminum hole or weld nut M5 Fasteners Torque 6 2 N m 55 in lb into new holes 4 0 N m 35 in lb into used holes M6 Fasteners Torque 10 7 N m 95 in lb into new holes 7 3 N m 65 in lb into used holes Blower Housing Screws into extruded hole or sheet metal M5 Fasteners Torque 2 8 N m 25 in lb in...

Page 13: ...it 0 088 mm 0 0035 in Connecting Rod to Crankpin Side Clearance 0 26 0 63 mm 0 0102 0 0248 in Connecting Rod to Piston Pin Running Clearance 21 C 70 F 0 015 0 028 mm 0 0006 0 0011 in Piston Pin End I D 21 C 70 F New 17 015 17 023 mm 0 6699 0 6702 in Max Wear Limit 17 036 mm 0 6707 in Crankcase Governor Cross Shaft Bore I D New 8 025 8 075 mm 0 3159 0 3179 in Max Wear Limit 8 088 mm 0 3184 in Breat...

Page 14: ...er Limit 0 022 mm 0 0009 in Max Out of Round Limit 0 025 mm 0 0010 in Closure Plate End Main Bearing Journal O D New 40 913 40 935 mm 1 6107 1 6116 in O D Max Wear Limit 40 84 mm 1 608 in Max Taper Limit 0 022 mm 0 0009 in Max Out of Round Limit 0 025 mm 0 0010 in Connecting Rod Journal O D New 35 950 35 973 mm 1 4153 1 4163 in O D Max Wear Limit 35 941 mm 1 415 in Max Taper Limit 0 018 mm 0 0007 ...

Page 15: ...Pump Module Baffle Fastener Torque 11 9 N m 105 in lb Fuel Pump Module Fastener Torque 9 2 N m 81 in lb Pulse Pump Bracket Fastener Torque 2 1 N m 25 in lb Pulse Pump Fastener to Bracket Torque 7 3 N m 68 in lb into new holes 6 2 N m 55 in lb into used holes Governor Governor Cross Shaft to Crankcase Running Clearance 0 025 0 126 mm 0 0009 0 0049 in Governor Cross Shaft O D New 7 949 8 000 mm 0 3129...

Page 16: ...d Intake Manifold Mounting Fastener Torque Torque in Two Stages first to 7 8 N m 69 in lb finally to 10 5 N m 93 in lb Manifold Absolute Pressure MAP Sensor Fastener Torque 7 3 N m 65 in lb Fuel Injector Cap Torque 7 3 N m 65 in lb Air Cleaner to Throttle Body Fastener Nut Torque 8 2 N m 73 in lb Heavy Duty Air Cleaner Mounting Bracket Fastener Torque 5 8 N m 51 in lb Muffler Muffler Retaining Nut T...

Page 17: ...Limit ECH730 ECH740 ECH749 0 94 mm 0 037 in Piston Thrust Face O D 2 ECH630 ECH650 ECH680 79 962 79 980 mm 3 1481 3 1488 in ECH730 ECH740 ECH749 82 949 82 967 mm 3 2657 3 2664 in Max Wear Limit ECH630 ECH650 ECH680 79 831 mm 3 1430 in Max Wear Limit ECH730 ECH740 ECH749 82 818 mm 3 2606 in Piston Thrust Cylinder to Bore2 Running Clearance New ECH630 ECH650 ECH680 0 020 0 063 mm 0 0008 0 0024 in Ne...

Page 18: ...e Guide Running Clearance 0 040 0 078 mm 0 0016 0 0031 in Exhaust Valve Stem to Valve Guide Running Clearance 0 052 0 090 mm 0 0020 0 0035 in Intake Valve Guide I D New 7 040 7 060 mm 0 2772 0 2780 in Max Wear Limit 7 134 mm 0 2809 in Exhaust Valve Guide I D New 7 040 7 060 mm 0 2772 0 2780 in Max Wear Limit 7 159 mm 0 2819 in Valve Guide Reamer Size Standard 7 050 mm 0 2776 in 0 25 mm O S 7 300 m...

Page 19: ...0 124 16 5 146 6 8 60 M8 10 5 93 13 6 120 24 4 216 33 9 300 40 7 360 17 0 150 Tightening Torque N m ft lb or 10 Property Class Noncritical Fasteners Into Aluminum M10 21 7 16 27 1 20 47 5 35 66 4 49 81 4 60 33 9 25 M12 36 6 27 47 5 35 82 7 61 116 6 86 139 7 103 61 0 45 M14 58 3 43 76 4 55 131 5 97 184 4 136 219 7 162 94 9 70 5 8 8 8 10 9 12 9 4 8 5 8 10 9 12 9 4 8 8 8 General Torque Values Metric ...

Page 20: ...67 8 50 3 8 24 54 2 40 81 4 60 7 16 14 47 5 35 74 6 55 108 5 80 7 16 20 61 0 45 101 7 75 142 4 105 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 2 110 244 1 180 352 6 260 5 8 18 189 8 140 311 9 230 447 5 330 3 4 10 199 3 150 332 2 245 474 6 350 3 4 16 271 2 200 440 7 325 637 3 470 Tightenin...

Page 21: ...gn Technology Inc DTI 019 DTI 021 DTI 023 DTI 035 DTI 027 DTI 029 DTI 037 Flywheel Holding Tool CS Series SE Tools KLR 82407 Flywheel Puller To remove flywheel from engine SE Tools KLR 82408 Flywheel Strap Wrench To hold flywheel during removal SE Tools KLR 82409 Section 2 Tools Aids Certain quality tools are designed to help you perform specific disassembly repair and reassembly procedures By usi...

Page 22: ...sed to test rectifier regulators Kohler 25 761 20 S Kohler 25 761 41 S Individual Components Available CS PRO Regulator Test Harness Special Regulator Test Harness with Diode Design Technology Inc DTI 031 DTI 033 Spark Advance Module SAM Tester To test the SAM ASAM and DSAM on engines with SMART SPARK Kohler 25 761 40 S Starter Servicing Kit All Starters To remove and reinstall drive retaining rin...

Page 23: ... 52 357 01 S Electric Starter Drive Lubricant Solenoid Shift Kohler 52 357 02 S RTV Silicone Sealant Loctite 5900 Heavy Body in 4 oz aerosol dispenser Only oxime based oil resistant RTV sealants such as those listed are approved for use Loctite Nos 5900 or 5910 are recommended for best sealing characteristics Loctite 5910 Loctite Ultra Black 598 Loctite Ultra Blue 587 Loctite Ultra Copper 5920 Koh...

Page 24: ...er Figure 2 1 Flywheel Holding Tool Rocker Arm Crankshaft Tool A spanner wrench to lift the rocker arms or turn the crankshaft may be made out of an old junk connecting rod 1 Find a used connecting rod from a 10 HP or larger engine Remove and discard the rod cap 2 Remove the studs of a Posi Lock rod or grind off the aligning steps of a Command rod so the joint surface is flat 3 Find a 1 in long cap...

Page 25: ...pump leaking or cracked 8 Intake system leak 9 Faulty ignition coil s 10 Blown fuse 11 Insufficient voltage to electronic control unit Engine Starts Hard 1 PTO drive is engaged 2 Dirt or water in the fuel system 3 Clogged fuel line or fuel filter 4 Loose or faulty wires or connections 5 Faulty or improperly adjusted throttle controls 6 Faulty spark plugs 7 Low compression 8 Weak spark 9 Fuel pump ma...

Page 26: ...is on these areas are causes of higher operating temperatures and overheating Check for obvious fuel and oil leaks and damaged components Excessive oil leakage can indicate a clogged or improperly assembled breather worn damaged seals and gaskets or loose or improperly torqued fasteners Check the air cleaner cover and base for damage or indications of improper fit and seal Check the air cleaner el...

Page 27: ...ly assembled breather can cause oil to be forced out at oil seals gaskets or other available spots Crankcase vacuum is best measured with either a water manometer or a vacuum gauge see Section 2 Complete instructions are provided in the kits To test the crankcase vacuum with the manometer 1 Insert the stopper hose into the oil fill hole Leave the other tube of manometer open to atmosphere Make sur...

Page 28: ...eel nut screw to hold it in position An assistant may be needed to hold the breaker bar during testing If the engine is mounted in a piece of equipment it may be possible to hold it by clamping or wedging a driven component Just be certain that the engine cannot rotate off of TDC in either direction 4 Install the adapter into the spark plug hole but do not attach it to the tester at this time 5 Con...

Page 29: ... Cap F Filter Minder G Inlet Screen H Retaining Clip Service Weekly and every 150 hours Check filter minder if equipped perform inspection of the paper element and inlet screen area See Figure 4 2 Yearly or every 300 hours of operation more often under extremely dusty or dirty conditions replace the paper element and check the inner element 1 Unhook the two retaining clips A on each end and remove...

Page 30: ...owed by the outer element B Slide each fully into place in the air cleaner housing D See Figure 4 2 7 Reinstall the end caps A and secure with the retaining clips H See Figure 4 2 Removal 1 Remove the three hex flange nuts securing the assembly to the throttle body See Figure 4 4 Figure 4 5 Heavy Duty Air Cleaner Bracket 3 Lift the entire air cleaner assembly off the engine Disassemble or service a...

Page 31: ...xploded View Figure 4 9 Base Plate Removal on Low Profile Air Cleaner 1 Loosen the cover retaining knob and remove the cover 2 Remove the foam precleaner from the paper air cleaner element 3 Wash the precleaner in warm water with detergent Rinse the precleaner thoroughly until all traces of detergent are eliminated Squeeze out excess water do not wring Allow the precleaner to air dry 4 Saturate th...

Page 32: ... element cover and wing nut 7 Reinstall the air cleaner cover and secure retaining knob Air Cleaner Components Whenever the air cleaner cover is removed or the paper element or precleaner are serviced check the following Air Cleaner Element Cover and Seal Make sure element cover is not bent or damaged Make sure the rubber sleeve seal is in place on the stud to prevent dust or dirt entry through th...

Page 33: ... 5 9 5 11 Engine Oil Temperature Sensor 5 11 5 12 Intake Air Temperature Sensor 5 12 Oxygen Sensor 5 13 5 15 Manifold Absolute Pressure MAP Sensor 5 16 Fuel Injectors 5 16 5 19 Ignition System 5 19 5 20 Spark Plugs 5 20 Battery Charging System 5 20 Fuel Components Fuel Pump 5 20 5 22 Fuel Filter 5 22 High Pressure Fuel Line 5 22 5 23 Purge Port and Vent Hose Assembly 5 23 Throttle Body Intake Mani...

Page 34: ... of the fuel system the pressure must be relieved by following Fuel Pump Module Fuel Connector Removal instructions below Fuel Pump Module Fuel Connector Removal Wrap a shop towel completely around the fuel pump module connector Press the release button s and slowly pull the connector away from the fuel pump module allowing the shop towel to absorb any residual fuel in the high pressure fuel line ...

Page 35: ...d the ignition timing by monitoring the primary sensor signals for engine temperature speed RPM and throttle position load These primary signals are compared to preprogrammed maps in the ECU computer chip and the ECU adjusts the fuel delivery to match the mapped values After the engine reaches operating temperature an exhaust gas oxygen sensor provides feedback to the ECU based upon the amount of ...

Page 36: ...ble failure a rev limiting feature is programmed into the ECU If the maximum RPM limit 4500 is exceeded the ECU suppresses the injection signals cutting off the fuel flow This process repeats itself in rapid succession limiting operation to the preset maximum Always depressurize the fuel system through the fuel connector on fuel pump module before disconnecting or servicing any fuel system componen...

Page 37: ...f operating problems and system errors as an actual component Refer to the Electrical System section for additional information Electrical System The 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 the operation of voltage sensitive components such as the ECU fuel pump ignition coils and injectors will be int...

Page 38: ... Ignition Coil 1 Ground 2 Battery Ground 3 Diagnostic Communication Line 4 Speed Sensor input 5 Fuel Injector Output 1 Ground 6 Fuel Injector Output 2 Ground 7 Oxygen Sensor Heater 8 Intake Air Temperature IAT sensor input 9 Fuel Pump Ground 10 Ground for IAT TPS MAP O2 and Oil Sensors 11 Manifold Absolute Pressure MAP sensor input 12 Throttle Position Sensor TPS input 13 Speed Sensor Ground 14 Oi...

Page 39: ... 18 1 9 10 18 RED WHITE WHITE BLACK BLACK BLACK BLACK BLACK BLACK BLACK BLACK BLACK BLACK RED WHITE RED BLACK GREY GREY PURPLE PURPLE PURPLE PURPLE TAN TAN DARK BLUE DARK BLUE DARK BLUE DARK BLUE DARK GREEN DARK GREEN DARK GREEN DARK GREEN YELLOW PINK LIGHT GREEN RED BLACK RED BLACK RED BLACK RED BLACK RED BLACK RED BLACK 3 1 2 6 4 5 Stator Rectifier Regulator Starter Motor RED RED 10A Fuse 6 Term...

Page 40: ...ITE BLACK BLACK BLACK BLACK YELLOW BLACK BLACK BLACK BLACK BLACK RED BLACK GREY GREY PURPLE PURPLE PURPLE PURPLE TAN TAN DARK BLUE DARK BLUE DARK BLUE DARK BLUE Key Switch DARK GREEN DARK GREEN DARK GREEN DARK GREEN YELLOW YELLOW PINK LIGHT GREEN RED BLACK RED BLACK RED BLACK RED BLACK RED BLACK RED BLACK E D A C B Stator Rectifier Regulator Starter Motor RED Accessory 10A Fuse 5 Terminal Connecto...

Page 41: ...ap of the sensor It must be 0 20 0 70 mm 0 008 0 027 in 2 Inspect the wiring and connections for damage or problems 3 Make sure the engine has resistor type spark plugs 4 Disconnect the Black connector from the ECU 5 Connect an ohmmeter between the 4 and 13 pin terminals A resistance value of 325 395 at room temperature 20 C 68 F should be obtained If resistance is correct check the mounting air g...

Page 42: ...re integrating the new sensor to the ECU Throttle Position Between Terminal Resistance Value Ω Continuity Closed A C 1400 1800 Yes Full with Stop Pin A C 3200 4100 Yes Full without Stop Pin A C 4600 5200 Yes Any A B 3000 7000 Yes Mounted on the throttle body and operated directly off the end of the throttle shaft the TPS works as a potentiometer varying the voltage signal to the ECU in direct corre...

Page 43: ...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 the idle speed to the final specified speed setting 6 Turn the key OFF and count to 10 seconds Learn is complete and the engine is ready for operation Engine Oil Temperature Sensor Figure 5 7 Engine Oil Temperature Sensor General The engine oil temperature sensor F...

Page 44: ...3900 5 Unplug the sensor from the wire harness and check the sensor resistance separately across the two pins Resistance value should again be 3100 3900 a If the resistance is out of specifications replace the temperature sensor b If it is within specifications proceed to Step 6 6 Check the circuits input ground from the main harness connector to the sensor plug for continuity damage etc Connect o...

Page 45: ... Heater 3 Lower Insulator 4 Stainless Steel Housing 5 Upper Insulator 6 Terminal Connection to Element 7 High Temp Water Seal Pin D Pin C Pin B Pin A Oxygen Sensor Service The temperature must be controlled very accurately and gas constituents measured to a high degree of accuracy for absolute sensor measurements Since this requires laboratory equipment it is not possible to distinguish a marginal...

Page 46: ... this cycling is not observed a determination must be made If the problem is with the engine or the sensor 3 Check engine harness for battery voltage on the heater circuit NOTE Using the diagnostic software the wiring and ECU integrity can be checked by grounding the signal wire the output of the sensor read on the software should be around 4 mv Removal Inspection 1 If the sensor has heavy deposit...

Page 47: ...e high quality fuel Engine problem misfire Correct cause of misfire Excessive rich air fuel ratio Correct air fuel ratio Wiring shorted to voltage Repair wiring Open circuit no activity from sensor Broken element Replace sensor Sensor dropped Hard blow to engine or exhaust system Defective sensor Thermal shock Slow time response Open heater circuit Replace sensor Improper handling Carbon deposits ...

Page 48: ... series of calibrated openings which directs the fuel into the manifold in a cone shaped spray pattern Figure 5 11 Manifold Absolute Pressure Sensor and Connector General The manifold absolute pressure MAP sensor provides immediate manifold pressure information to the ECU The MAP measures the difference in pressure between the outside atmosphere and the vacuum level inside the intake manifold and m...

Page 49: ...t noid light part of EFI Service Kit see Section 2 into one connector 8 2 The injectors have sequential fueling that open and close once every other crankshaft revolution The amount of fuel injected is controlled by the ECU and determined by the length of time the valve needle is held open also referred to as the injection duration or pulse width The time the injector is open milliseconds may vary...

Page 50: ...askets 18 Position the manifold assembly over an appropriate container to capture fuel and turn the key switch ON to activate the fuel pump and pressurize the system Do not turn switch to START position 19 If either injector exhibits leakage of more than two to four drops per minute from the tip or shows any sign of leakage around the outer shell turn the ignition switch OFF and replace the inject...

Page 51: ...e if clogging has been a problem Ignition System Figure 5 16 Ignition Coil General A high voltage solid state battery ignition system is used with the EFI system The ECU controls the ignition output and timing through transistorized control of the primary current delivered to the coils Based on input from the crankshaft position sensor the ECU determines the correct firing point for the speed at w...

Page 52: ...Connect an ohmmeter set on the Rx10K scale between the spark plug boot terminal and the B primary terminal Secondary resistance should be 6400 7800 4 If the secondary resistance is not within the specified range the coil is faulty and needs to be replaced NOTE If the ignition coil s are disabled and an ignition fault is registered the system will automatically disable the corresponding fuel inject...

Page 53: ...pump may be conducted 1 Relieve fuel pressure at the fuel pump module following the instructions on page 5 2 The fuel pump module may need to be loosened or pulled away from the engine Disconnect the fuel coupler from the fuel pump module and insert the pressure test jumper from Kohler EFI Service Kit between the high pressure fuel line and the fuel pump module 2 Connect the black hose of Pressure...

Page 54: ...n the pump terminals replace the fuel pump b If the voltage was below 7 test the wiring harness 7 If voltage at the plug was good and there was continuity across the pump terminals reconnect the plug to the pump making sure you have a good connection Turn on the key switch and listen for the pump to activate a If the pump starts repeat steps 2 and 3 to verify correct pressure b If the pump still d...

Page 55: ...ent hoses Service The high pressure fuel line is mounted to the intake manifold No specific servicing is required unless operating conditions indicate that it needs replacement It can be detached by removing the two mounting screws wire ties and the injector retaining clips Thoroughly clean the area around all joints and relieve any pressure before starting any disassembly by following the instruc...

Page 56: ...cturer See Figure 5 23 4 If the idle speed is adjusted up over 1800 RPM you must first decrease idle RPM to 1500 RPM and then up to final idle speed setting for the TPS to be properly learned by the ECU 5 The idle speed adjustment can affect the high idle speed setting Move the throttle control to the full throttle position and check the high idle speed Adjust as necessary to 3750 RPM or the speed ...

Page 57: ...t the governor arm has not twisted up or down after the nut has been tightened Figure 5 27 Checking Split of Clamp 2 Follow the instructions in Step 2 of Checking the Initial Adjustment then reattach the throttle linkage to the governor lever with the bushing clip It is not necessary to reattach the damper or governor springs at this time Figure 5 28 Adjusting Governor Shaft 4 Verify that the gove...

Page 58: ...mperature sensor 6 Faulty injectors Engine misses hesitates or stalls under load 1 Fuel injector s fuel filter fuel line or fuel pick up dirty restricted 2 Dirty air cleaner 3 Insufficient fuel pressure or fuel delivery 4 Vacuum intake air leak 5 Improper governor setting adjustment or operation 6 TPS faulty mounting problem or TPS Learn Procedure incorrect 7 Bad coil s spark plug s or wires Low Pow...

Page 59: ...ning and dealer service is required Upon receipt the dealer technician can access the fault code s to help determine what portion of the system is malfunctioning The 4 digit fault codes available are listed on page 5 29 The codes are accessed through the key switch and displayed as blinks or flashes of the MIL Access the codes as follows 1 Check that the battery voltage is above 11 volts 2 Start w...

Page 60: ...ded easily for quick diagnostics The main engine to vehicle connection will have a tan wire which is the ground for the MIL Either incandescent or LED type bulbs can be used for the MIL as long as they do not draw more than 0 1 amps The bulb needs to be rated at 1 4 Watts or less or needs to have a total resistance of 140 Ω or more LEDs typically draw less than 0 03 amps Attach 12 volts to the pos...

Page 61: ...tage 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 M...

Page 62: ...ess and connectors loose damaged or corroded c Pin circuit wiring or connectors at Black 10 11 and 16 3 Bad TPS Learn Code 0108 Component Manifold Absolute Pressure Sensor Fault MAP Circuit High Voltage Condition Intake manifold leak shorted connection or faulty sensor Possible Causes 1 MAP Sensor Related a Sensor malfunction b Vacuum leaks from loose manifold or sensor 2 Wire Harness Related a Po...

Page 63: ...horted wire in harness 1 ECU Black pin 10 to TPS pin 1 2 ECU Black pin 12 to TPS pin 3 3 ECU Black pin 16 to TPS pin 2 3 Throttle Body Related a Throttle shaft inside TPS worn broken or damaged b Throttle plate loose or misaligned c Throttle plate bent or damaged allowing extra airflow past or restricting movement 4 ECU Related a Circuit providing voltage or ground to TPS damaged b TPS signal inpu...

Page 64: ...oltage between sensed voltage and actual sensor voltage b Problem in wiring harness c ECU to harness connection problem 4 Systems Related a Ignition spark plug plug wire ignition coil b Fuel fuel type quality injector fuel pressure too low fuel pump module or lift pump c Combustion air air cleaner dirty restricted intake leak throttle bores d Base engine problem rings valves e Exhaust system leak ...

Page 65: ...tor Related a Injector coil shorted or opened 2 Engine Wiring Harness Related a Broken or shorted wire in harness ECU pin Black 5 b Wiring from Ignition 3 ECU Related a Circuit controlling injector 1 damaged Code 0202 Component Fuel Injector Fault Injector 2 Circuit Malfunction Condition Injector damaged or faulty shorted or open connection Possible Causes 1 Injector Related a Injector coil shorte...

Page 66: ...n circuit wiring or connectors ECU pin Black 4 or Black 13 b ECU to harness connection problem 4 If code is stored in fault history and starts normally Clear code no other service required 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 Possible Causes 1 Engine Wiring Harness Relate...

Page 67: ...ery Code 61 Fault End of Code Transmission Troubleshooting Flow Chart The following flow chart provides an alternative method of troubleshooting the EFI system The chart will enable you to review the entire system in about 10 15 minutes Using the chart the accompanying diagnostic aids listed after the chart and any signaled fault codes you should be able to quickly locate any problems within the s...

Page 68: ...AGNOSTIC AID 2 FAULT CODES CLEAR CODES NO REFER TO DIAGNOSTIC AID 3 RUN ON OPERATE AT VARIOUS SPEED LOAD CONDITIONS ARE FAULT CODES PRESENT NO END OF TEST REFER TO DIAGNOSTIC AID 4 CRANKSHAFT POSITION SENSOR REFER TO DIAGNOSTIC AID 5 FUEL PUMP REFER TO DIAGNOSTIC AID 6 IGNITION SYSTEM REFER TO DIAGNOSTIC AID 7 FUEL SYSTEM ELECTRICAL REFER TO DIAGNOSTIC AID 8 FUEL SYSTEM REFER TO DIAGNOSTIC AID 9 B...

Page 69: ...adaptation limit exceeded Code 0172 Minimum adaptation limit exceeded Code 0174 Lean fuel condition at high load or open loop Code 0201 Injector 1 Circuit Malfunction Code 0202 Injector 2 Circuit Malfunction Code 0230 Fuel Pump Module Circuit Low Voltage or Open Code 0232 Fuel Pump Module Circuit High Voltage Code 0336 Crankshaft Position Sensor Noisy Signal Code 0337 Crankshaft Position Sensor No...

Page 70: ... 8 ECU 9 Lift pump not working Diagnostic Aid 8 FUEL SYSTEM fuel pressure Possible causes for low fuel system pressure 1 Low fuel 2 Fuel filter plugged 3 Fuel supply line plugged 4 Lift fuel pump insufficient fuel supply 5 Fuel pump lift or module internally plugged Possible causes for high fuel system pressure 1 Pressure regulator not functioning properly inside fuel pump module Diagnostic Aid 9 BA...

Page 71: ...ican Petroleum Institute service class SJ or higher Select the viscosity based on the air temperature at the time of operation as shown in the following table NOTE Using other than service class SJ or higher oil or extending oil change intervals longer than recommended can cause engine damage NOTE Synthetic oils meeting the listed classifications may be used with oil changes performed at the recom...

Page 72: ...install oil fill cap and dipstick Figure 6 4 Oil Level Marks on Dipstick NOTE To prevent extensive engine wear or damage always maintain the oil level in the correct operating range Never operate the engine with the oil level below the L mark or above the F mark on the dipstick Oil Disposal Protect and respect the environment Dispose of oil at your local recycling center or municipal collection ce...

Page 73: ...filter side Allow ample time for complete drainage See Figures 6 3 6 5 and 6 6 2 Reinstall the drain plug and torque to 13 6 N m 10 ft lb 3 To keep dirt debris etc out of the engine clean the area around the oil filter remove the oil filter See Figure 6 8 4 Wipe the surface where the oil filter mounts 5 Place a new filter in a shallow pan with the open end up Pour new oil of the proper type in thr...

Page 74: ...RE EACH USE and is maintained up to the F mark on the dipstick This includes engines equipped with Oil Sentry Installation The Oil Sentry pressure switch is installed into the breather cover See Figure 6 10 Figure 6 10 Location of Oil Sentry Switch Oil Cooler Oil Cooler 10 Test run the engine to check for leaks Stop the engine allow a minute for the oil to drain down and recheck the level on the d...

Page 75: ...the pressure to the switch As pressure increases through the range of 2 0 5 0 psi the tester should indicate a change to no continuity switch open The switch should remain open as the pressure is increased to 90 psi maximum 3 Gradually decrease the pressure through the range of 2 0 5 0 psi The tester should indicate a change to continuity switch closed down to 0 psi 4 Replace the switch if it does...

Page 76: ...6 6 Section 6 Lubrication System ...

Page 77: ...fter every 200 hours of operation Check their condition and either reset the gap or replace with new plugs as necessary To service the plugs perform the following steps 1 Before removing a spark plug clean the area around the base of the plug to keep dirt and debris out of the engine 2 Remove the plug and check its condition See Inspection following this procedure Replace the plug if necessary NOT...

Page 78: ...e will be rounded and the gap will be greater than the specified gap Replace a worn spark plug immediately Wet Fouled A wet plug is caused by excess fuel or oil in the combustion chamber Excess fuel could be caused by a restricted air cleaner or rich air fuel ratio Oil in the combustion chamber is usually caused by a restricted air cleaner a breather problem or worn piston rings cylinder walls or ...

Page 79: ...re disconnecting the negative ground cable make sure all switches are OFF If ON a spark will occur at the ground cable terminal which could cause an explosion if hydrogen gas or gasoline vapors are present 1 Regularly check the level of electrolyte Add distilled water as necessary to maintain the recommended level NOTE Do not overfill the battery Poor performance or early failure due to loss of el...

Page 80: ...any electric welding on the equipment powered by the engine Also disconnect all other electrical accessories in common ground with the engine Prevent the stator AC leads from touching or shorting while the engine is running This could damage the stator Stator The stator is mounted on the crankcase behind the flywheel Follow the procedures in Section 8 Disassembly and Section 10 Reassembly if stato...

Page 81: ... with the rectifier regulator mounted or loose The figures show the part removed from the engine for clarity Repeat the applicable test procedure two or three times to determine the condition of the part 1 Connect the tester ground lead with spring clamp to the body of the rectifier regulator 2 Connect the red lead from the tester to the middle terminal labeled B 3 Connect the two black leads from...

Page 82: ...n alternative connect a jumper lead from rectifier regulator housing to the battery ground and retest charging voltage If charge voltage measures 13 7 14 7 volts the charging system is functioning If resistance is greater than 1 ohm or charge voltage is less than 13 7 then re establish ground between the ground strap and mounting screw If voltage is less than 13 8 or charge rate does not increase ...

Page 83: ...t start allow a 60 second cool down period between starting attempts Failure to follow these guidelines can burn out the starter motor NOTE If the starter cranks the engine but does not start the engine the engine rotation must be allowed to come to a complete stop before attempting to restart the engine again If the starter is engaged while the flywheel is rotating the starter pinion and flywheel...

Page 84: ...charge or replace battery as necessary Wiring 1 Clean corroded connections and tighten loose connections 2 Replace wires in poor condition and with frayed or broken insulation Starter Switch or Solenoid 1 By pass the switch or solenoid with a jumper wire If starter cranks normally replace the faulty components Solenoid Shift Starters Perform individual solenoid test procedure See pages 7 16 and 7 ...

Page 85: ... starter solenoid on pages 7 16 and 7 17 Torx Head Screws Figure 7 11 Solenoid Removed from Starter 3 Remove the two thru larger bolts See Figure 7 12 Figure 7 12 Removing Thru Bolts 4 Remove the commutator end plate assembly containing the brush holder brushes springs and locking caps Remove the thrust washer from inside the commutator end See Figure 7 13 Figure 7 13 Removing Commutator End Plate...

Page 86: ... 6 Remove the rubber grommet and backing plate from the end cap See Figure 7 15 Figure 7 15 Rubber Grommet and Backing Plate 7 Take out the drive lever and pull the armature out of the drive end cap See Figure 7 16 8 Remove the thrust washer from the armature shaft See Figure 7 16 Figure 7 18 Removing Retaining Ring 11 Remove the drive pinion assembly from the armature 12 Clean the parts as requir...

Page 87: ...hes Armature 1 Clean and inspect the commutator outer surface The mica insulation must be lower than the commutator bars undercut to ensure proper operation of the commutator See Figure 7 20 Figure 7 20 Commutator Mica Inspection 2 Use an ohmmeter set to the Rx1 scale Touch the probes between two different segments of the commutator and check for continuity See Figure 7 21 Test all the segments Con...

Page 88: ... assembly See Figure 7 24 a Install the stop collar down onto the armature shaft with the counter bore recess up b Install a new retainer in the larger rear groove of the armature shaft Squeeze with a pliers to compress it in the groove c Slide the stop collar up and lock it into place so the recess surrounds the retainer in the groove If necessary rotate the pinion outward on the armature splines...

Page 89: ...backup washer See Figure 7 26 Figure 7 26 Installing Armature and Pivot Lever Figure 7 27 Installing Backing Plate and Grommet 8 Install the frame with the small notch forward onto the armature and drive end cap Align the notch with the corresponding section in the rubber grommet Install the drain tube in the rear cutout if it was removed previously See Figure 7 28 7 Install the backing plate foll...

Page 90: ...D of the brush holder assembly Insert the Brush Installation Tool with extension or use the tube described above from a prior brush installation through the brush holder assembly so the holes in the metal mounting clips are up out c Install the brush springs and snap on the four retainer caps See Figure 7 32 Figure 7 30 Installing Brush Holder Assembly with Supplied Tube Starter reassembly when no...

Page 91: ...nting screws to 2 5 3 3 N m 22 29 in lb See Figures 7 34 and 7 35 Figure 7 35 Torquing Brush Holder Screws 13 Hook the plunger behind the upper end of the drive lever and install the spring into the solenoid Insert the three mounting screws through the holes in the drive end cap Use these to hold the solenoid gasket in position then mount the solenoid Torque the screws to 4 0 6 0 N m 35 53 in lb 1...

Page 92: ... the solenoid for any time over what is necessary for performing each of the individual tests Internal damage to the solenoid may otherwise occur Figure 7 37 Testing Pull In Coil Plunger Actuation Test 2 Solenoid Pull In Coil Contact Continuity Use an ohmmeter set to the audible or Rx2K scale and connect the two ohmmeter leads to the two large post terminals Perform the preceding test 1 and check ...

Page 93: ...to the audible or Rx2K scale and connect the two ohmmeter leads to the two large post terminals Perform the preceding test 3 and check for continuity See Figure 7 40 The meter should indicate continuity if no continuity is indicated the solenoid should be replaced Repeat test several times to confirm condition Figure 7 40 Testing Hold In Coil Solenoid Contact Continuity ...

Page 94: ...7 18 Section 7 Electrical System and Components ...

Page 95: ...ove Electronic Control Unit ECU 12 Remove ECU bracket and electric starter motor 13 Remove grass screen 14 Remove outer baffles and blower housing 15 Remove Oil Sentry 16 Remove oil temperature sensor 17 Remove inner baffles and breather cover 18 Remove valve covers 19 Remove crankshaft position sensor 20 Remove manifold absolute pressure MAP sensor 21 Remove fuel injectors 22 Remove intake manifold 2...

Page 96: ... models are equipped with an oil drain valve Figure 8 2 Removing Dipstick Oil Fill Cap from Tube Figure 8 4 Removing Oil Filter Remove Oil Cooler 1 Use an 8 mm Allen wrench to remove the oil filter threaded nipple See Figure 8 5 Figure 8 6 Removing Oil Cooler Figure 8 5 Oil Filter Threaded Nipple 2 Separate the filter adapter from the closure plate leaving the oil lines attached Remove the two hex...

Page 97: ... Remove the element cover the air cleaner element with precleaner and the stud seal See Figure 8 9 Figure 8 9 Removing Air Cleaner Element Precleaner and Stud Seal 4 Remove the three hex flange nuts See Figure 8 10 5 Remove the two hex flange screws securing the base and then remove the base See Figures 8 10 and 8 11 Figure 8 10 Removing Air Cleaner Base Nuts Figure 8 8 Air Cleaner Bracket Mountin...

Page 98: ...tle Control Panel Remove External Governor Controls 1 Disconnect the governor spring attaching the governor lever to the throttle actuator lever See Figure 8 12 Throttle Throttle Linkage Linkage Spring Spring Throttle Throttle Linkage Linkage Throttle Throttle Linkage Linkage Bushing Bushing Remove Hex Flange Remove Hex Flange Screws Screws WARNING Explosive Fuel can cause fires and severe burns D...

Page 99: ...Wrap a shop towel completely around the fuel pump module connector Press the release button s and slowly pull the connector away from the fuel pump module allowing the shop towel to absorb any residual fuel in the high pressure fuel line Any spilled fuel must be completely wiped up immediately Figure 8 18 Fuel Pump Mounting Screw Locations 4 Note or mark the orientation of the fuel pump then remov...

Page 100: ...isconnect the intake air temperature sensor from the throttle body See Figure 8 24 Grey Release Tab Grey Release Tab Release Button Release Button Figure 8 20 Remove Inlet Fuel Line and Oetiker Clamp 3 Disconnect the yellow electrical connector by pulling up on the grey tab to release See Figure 8 21 Figure 8 21 Disconnect Electrical Connector 4 Wrap a shop towel completely around the high pressur...

Page 101: ... off the intake manifold Remove Electronic Control Unit ECU 1 Remove the two hex flange screws securing the ECU to the bracket See Figure 8 27 Figure 8 27 Removing ECU Fasteners 2 Disconnect the Black and Grey electrical connectors from the ECU See Figure 8 28 Figure 8 28 Disconnecting the ECU Electrical Connectors Remove Electronic Control Unit Bracket and Electric Starter Motor 1 Disconnect the l...

Page 102: ...ure 8 33 The coil and any hoses may remain attached to the baffle after being unplugged or disconnected Figure 8 33 Note Location of Short Screws Remove Grass Screen 1 Remove the four socket head cap screws securing the metal grass screen and remove the screen See Figure 8 30 Figure 8 30 Remove Metal Grass Screen 2 Remove the four spacers paying attention to the curvature of the spring washers betwe...

Page 103: ...e 8 37 5 Remove the outer baffles See Figure 8 34 Figure 8 35 Removing Blower Housing Remove Oil Sentry 1 Disconnect the lead from the Oil Sentry switch See Figure 8 36 Figure 8 37 Removing Oil Temperature Sensor Lead 2 Remove the oil temperature sensor from the breather cover NOTE Unless the oil temperature sensor is damaged or malfunctioning disassembly from the breather cover is unnecessary 3 Rem...

Page 104: ...ting in leaks Figure 8 41 Removing Breather Cover and Gasket Figure 8 42 Removing Valve Cover Remove Crankshaft Position Sensor 1 Remove the two hex flange screws securing the crankshaft position sensor bracket See Figure 8 43 Remove Valve Covers 1 Remove the four hex flange screws securing each valve cover Note valve cover differences for proper location in reassembly Ensure any brackets removed a...

Page 105: ... 8 46 Removing MAP Screw Electrical Electrical Connector Connector Remove Fuel Injectors 1 Disconnect the electrical connector See Figure 8 47 Slide Slide Locking Locking Tab Tab Figure 8 45 Slide Locking Tab on Connector 2 Detach the connector 3 Remove the hex flange screw and pull the MAP sensor out of the intake manifold See Figure 8 46 Figure 8 48 Removing Fuel Injectors 3 When removed pull th...

Page 106: ...old the wiring clamp 3 Unclasp the wiring harness from the clip using a screwdriver See Figure 8 51 Figure 8 51 Release Wire Harness Clip Studs Hex Flange Nuts and Washers Shown Figure 8 52 Removing Spark Plugs Remove Cylinder Heads and Hydraulic Lifters NOTE Cylinder heads are retained using either hex flange screws or hex flange nuts and washers on studs Do not interchange or mix components 1 Re...

Page 107: ... Lifters Disassemble Cylinder Heads 1 Remove the two hex flange screws rocker arm pivots and rocker arms from the cylinder head See Figure 8 57 2 Mark the location of the push rods as either intake or exhaust and cylinder 1 or 2 Push rods should always be reinstalled in the same positions 3 Carefully remove the push rods cylinder heads and head gaskets See Figure 8 54 Figure 8 55 Removing Hydrauli...

Page 108: ...rts from one cylinder head to the other Valve Retainer Spring Keepers Cap Figure 8 61 Removing Fan 2 Use a flywheel strap wrench or holding tool see Section 2 to hold the flywheel and loosen the hex flange screw securing the flywheel to the crankshaft See Figure 8 62 NOTE Always use a flywheel strap wrench or holding tool to hold the flywheel when loosening or tightening the flywheel screw Do not ...

Page 109: ...Do not strike the crankshaft or flywheel as these parts could become cracked or damaged Striking the puller or crankshaft can cause the crank gear to move affecting crankshaft endplay Figure 8 65 Removing Stator Remove Closure Plate Assembly 1 Remove the ten hex flange screws securing the closure plate to the crankcase See Figure 8 66 Figure 8 66 Removing Closure Plate Fasteners 2 Locate the splitt...

Page 110: ...Remove Camshaft 1 Remove the camshaft See Figure 8 68 Figure 8 68 Removing Camshaft Remove Governor Cross Shaft 1 Remove the retainer and nylon washer from the governor cross shaft See Figure 8 68 Figure 8 69 Removing Governor Cross Shaft Retainer 2 Remove the cross shaft through the inside of the crankcase See Figure 8 70 Camshaft Figure 8 70 Removing Governor Cross Shaft Remove Connecting Rods w...

Page 111: ... for reassembly Do not mix end caps and connecting rods Figure 8 72 Removing Connecting Rod and Piston Assembly 3 Repeat the above procedure for the other connecting rod and piston assembly Figure 8 75 Removing Oil Seal Remove Crankshaft 1 Carefully pull the crankshaft from the crankcase See Figure 8 74 Figure 8 73 Removing Piston Pin 4 Remove piston pin from piston for inspection Use a small scre...

Page 112: ...8 18 Section 8 Disassembly ...

Page 113: ...Engine Inspection Data Record TP 2435 are also available use these to record inspection results Camshaft Inspection and Service Check the lobes of the camshaft for wear or damage See Section 1 for minimum lift specifications The measurement must be performed while the valve train is still assembled Inspect the cam gear for badly worn chipped or missing teeth Replacement of the camshaft will be nec...

Page 114: ...into the plug bore until it seats at the bottom of the bore Make sure the plug is tapped in evenly to prevent leakage Figure 9 2 Removing Crankpin Plug Crankcase Inspection and Service Check all gasket surfaces to make sure they are free of gasket fragments Gasket surfaces must also be free of deep scratches or nicks Inspect the main bearing if so equipped for wear or damage refer to Section 1 Spe...

Page 115: ...intersect at approximately 23 33 off the horizontal Too flat an angle could cause the rings to skip and wear excessively and too steep an angle will result in high oil consumption See Figure 9 3 Figure 9 3 Cylinder Bore Crosshatch after Honing 4 After resizing check the bore for roundness taper and size Use an inside micrometer telescoping gauge or bore gauge to take measurements The measurements s...

Page 116: ... the flywheel keyway for damage Replace the flywheel if it is cracked Replace the flywheel the crankshaft and the key if flywheel key is sheared or the keyway is damaged Inspect the ring gear for cracks or damage Kohler does not provide the ring gear as a serviceable part Replace the flywheel if the ring gear is damaged Cylinder Head and Valves Inspection and Service After cleaning check the flatn...

Page 117: ... 2987 1 2997 in 4 mm 0 1575 in 7 038 7 058 mm 0 2771 0 2779 in 29 37 29 63 mm 1 1563 1 1665 in 45 1 5 mm 0 0591 in 6 970 6 988 mm 0 2744 0 2751 in Figure 9 6 Valve Details 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 the valves first After removal clean the valve ...

Page 118: ...t 1000 hours under controlled test conditions Bad Condition The valve depicted here should be replaced Note the warped head margin damaged and too narrow These conditions could be attributed to excessive hours or a combination of poor operating conditions Leakage A poor grind on face or seat of valve will allow leakage resulting in a burned valve on one side only Coking Coking is normal on intake ...

Page 119: ...on their condition Stem Corrosion Moisture in fuel or from condensation are the most common causes of valve stem corrosion Condensation occurs from improper preservation during storage and when engine is repeatedly stopped before it has a chance to reach normal operating temperatures Replace corroded valves Overheating An exhaust valve subject to overheating will have a dark discoloration in the a...

Page 120: ...ut should be made with an 89 cutter as specified for the valve seat angle in Figure 9 6 Cutting the proper 45 valve face angle as specified in Figure 9 6 and the proper valve seat angle 44 5 half of the full 89 angle will achieve the desired 0 5 1 0 full cut interference angle where the maximum pressure occurs on the outside diameters of the valve face and seat Figure 9 7 Typical Valve Seat Cutter...

Page 121: ...tick 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 the fuel charge ignites spontaneously from heat and pressure shortly after ignition This creates two flame fronts which meet and explode to create extreme hamm...

Page 122: ...rvicing piston rings 1 The cylinder bore must be deglazed before service ring sets are used 2 If the cylinder bore does not need reboring and if the old piston is within wear limits and free of score or scuff marks the old piston may be reused 3 Remove the old rings and clean up the grooves Never reuse old rings 4 Before installing the new rings on the piston place the top two rings each in turn in...

Page 123: ...nces and Special Torque Values Replace the 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 The 0 25 mm 0 010 in undersized rod can be identified by the drilled hole located in the lower end of the rod shank Always refer to the appropriate parts information to ensure that correct replacements are used Hy...

Page 124: ...fore remove the gear only if absolutely necessary 1 Remove the regulating pin and governor gear assembly See Figure 9 13 Figure 9 13 Removing Governor Gear 2 Remove the locking tab thrust washer located under the governor gear assembly 3 Carefully inspect the governor gear shaft and replace it only if it is damaged After removing the damaged shaft press or lightly tap the replacement shaft into th...

Page 125: ...Figure 9 16 b Install fastener into location No 2 and fully torque to the recommended value See Figure 9 16 c Torque fastener in location No 1 to the recommended value See Figure 9 16 2 0 mm 0 0787 in Governor Cross Shaft Seal First Time Installation 10 7 N m 95 in lb All Reinstallations 6 7 N m 60 in lb Figure 9 16 Oil Pump Torque Sequence 4 After torquing rotate the gear and check for freedom of...

Page 126: ...9 14 Section 9 Inspection and Reconditioning ...

Page 127: ...l flywheel end oil seal 2 Install crankshaft 3 Install connecting rods with pistons and rings 4 Install governor cross shaft 5 Install camshaft 6 Install closure plate oil seal 7 Install closure plate assembly 8 Install stator and backing plate 9 Install flywheel 10 Install flywheel fan 11 Install hydraulic lifters and cylinder heads 12 Install push rods and rocker arms 13 Install spark plugs 14 I...

Page 128: ...rods Figure 10 5 Installing Piston Assembly Using Ring Compressor Tool Figure 10 2 Installing Oil Seal Install Crankshaft 1 Lubricate the crankshaft journals and connecting rod bearing surfaces with engine oil 2 Carefully slide the flywheel end of the crankshaft through the main bearing in the crankcase See Figure 10 3 Figure 10 4 Piston Connecting Rod and Pin Detail 1 Stagger the piston rings in ...

Page 129: ... the proper end play See Figures 10 7 and 10 8 4 Install the inner rod cap to the connecting rod using the two hex flange screws Torque in increments to 11 6 N m 103 in lb See Figure 10 6 Illustrated instructions are provided in the service rod package NOTE Align the chamfer of the connecting rod with the chamfer of its mating end cap When installed the flat faces of the connecting rods should fac...

Page 130: ...embly procedures under Governor Gear Assembly in Section 9 Thrust Bearing Washer and Shim Some specifications use a needle type thrust bearing thrust washer and shim spacer to control the end play of the crankshaft See Figure 10 11 If these items are noted during disassembly make sure they are reinstalled in the sequence shown in Figure 10 12 A different procedure will have to be followed to check ...

Page 131: ... 10 or in Service Bulletin 252 2 Check to make sure that there are no nicks or burrs on the sealing surfaces of the closure plate or crankcase 3 Apply a 1 5 mm 1 16 in bead of sealant to the sealing surface of the closure plate Verify O ring is present See Figure 10 14 for sealant pattern Oil Seal 8 0 mm 0 314 in Seal Depth Figure 10 13 Oil Seal Depth in Closure Plate Install Closure Plate Assembl...

Page 132: ...e crankcase Torque fasteners in the sequence shown in Figure 10 16 to 25 6 N m 227 in lb One of the ten mounting screws has a thread sealant patch This screw is typically installed in the 10 hole shown in Figure 10 16 Reapply pipe sealant with Teflon Loctite 592 PST Thread Sealant or equivalent Figure 10 17 Torquing Closure Plate Fasteners Install Stator and Backing Plate 1 Apply pipe sealant with...

Page 133: ...ersonal injury since broken fragments could be thrown from the engine Always observe and use the following precautions and procedures when installing the flywheel NOTE Before installing the flywheel make sure the crankshaft taper and the flywheel hub are clean dry and completely free of any lubricants The presence of lubricants can cause the flywheel to be over stressed and damaged when the hex fl...

Page 134: ... Installing Hydraulic Lifters NOTE Hydraulic lifters should always be installed in the same position as before disassembly The exhaust lifters are located on the output shaft side of the engine while the intake lifters are located on the fan side of the engine The cylinder numbers are embossed on the top of the crankcase and each cylinder head See Figure 10 28 Figure 10 28 Match Numbers on Crankca...

Page 135: ...faces of the cylinder head or the crankcase Heads secured with mounting studs nuts and washers 2 If all of the 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 the crankcase a Thread and lock two of the mounting nuts together on the smaller diamet...

Page 136: ...d is flat on the gasket and dowel pins 6 Lightly lubricate the exposed upper threads of the studs with engine oil Install a flat washer and hex nut onto each of the mounting studs Torque the hex nuts in two stages first to 16 9 N m 150 in lb finally to 33 9 N m 300 in lb See Figure 10 33 Follow the torque sequence in Figure 10 36 Figure 10 34 Always Use New Head Gaskets NOTE Match the numbers embo...

Page 137: ...ther intake or exhaust and cylinder 1 or 2 Dip the ends of the push rods in engine oil and install making sure that each push rod ball seats in its hydraulic lifter socket See Figure 10 37 Figure 10 37 Install Push Rods in Their Original Position 2 Apply grease to the contact surfaces of the rocker arms and rocker arm pivots Install the rocker arms and rocker arm pivots on one cylinder head and st...

Page 138: ... crankcase post and torque the hex flange screw to 4 0 N m 35 in lb into used holes or 6 2 N m 55 in lb into new holes See Figure 10 43 Figure 10 43 Install Wire Harness Clip 4 Place wire harness conduit in clip and snap clip together Install Fuel Injectors NOTE Ensure all parts are clean undamaged and free of debris and make sure the electrical connectors have the seal in place NOTE The O rings a...

Page 139: ...e of debris and make sure the electrical connectors have the seal in place 1 Install the crankshaft position sensor and bracket assembly to the crankcase posts 2 Snug the hex flange screws and check the air gap of the sensor with a feeler gauge It must be 0 20 0 70 mm 0 008 0 027 in 3 Torque the bracket screws to the crankcase to 4 0 N m 35 in lb into used holes or 6 2 N m 55 in lb into new holes ...

Page 140: ...ces 3 Install a new O ring in the groove of each cover 4 Position the covers on the cylinder heads including any clips lifting straps or brackets that were present prior to disassembly Install the four hex flange screws in each cover and finger tighten 5 Torque the valve cover fasteners to 6 2 N m 55 in lb using the sequence shown in Figure 10 48 1 2 3 4 Figure 10 48 Valve Cover Fastener Torque Se...

Page 141: ...ectrical connector has the seal in place 1 Lightly oil the oil temperature sensor O ring and install the oil temperature sensor into the breather cover 2 Torque the sensor to 7 3 N m 65 in lb See Figure 10 54 Figure 10 54 Torque Oil Temperature Sensor 3 Push the electrical connector on the oil temperature sensor making sure a good connection is made Install Oil Sentry If So Equipped 1 Apply pipe s...

Page 142: ...en to the Oil Sentry terminal 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 the blower housing into position over the front edge of the inner baffles See Figure 10 56 Start a few of the screws to hold it in place Figure 10 56 Installing Blower Housing 2 Position the outer baffles and secure usin...

Page 143: ...terminal into the plug prior to connecting to the rectifier regulator See Figure 10 61 NOTE The rectifier regulator middle terminal B is offset not equally spaced from the outer terminals AC Verify the rectifier regulator plug is assembled to match the terminal offset of the rectifier regulator 1 5 2 3 4 Figure 10 61 Attaching Rectifier Regulator Plug Install Grass Screen Metal Grass Screen 1 Verify...

Page 144: ... end down The smaller diameter should extend through the spring washer and fan so the tip is resting on the flywheel and the shoulder is resting on the spring washer See Figure 10 63 Torque Screws Torque Screws Figure 10 64 Torque Metal Grass Screen Screws Plastic Grass Screen 1 Place the plastic grass screen on the fan and secure with four hex screws Torque the four screws to 4 0 N m 35 in lb See...

Page 145: ...used Install Throttle Body 1 Install a new throttle body O ring prior to installation Make sure all holes align and are open 2 Install the throttle body throttle position sensor intake air temperature sensor throttle linkage spring and bushing as an assembly See Figure 10 69 Torque Bracket Screws Torque Bracket Screws Figure 10 69 Installing Throttle Body Assembly 3 Install the air cleaner bracket...

Page 146: ...tions connect the in line 51 75 micron mesh fuel filter and hose to the inlet barb of the lift fuel pump and secure with a spring clamp The in line 10 micron EFI paper fuel filter and hose must be connected to the outlet barb of the lift fuel pump and secured with a spring clamp See Figure 10 72 Figure 10 71 Installing Breather Hose and Intake Air Temperature Sensor Connector 6 Connect the 5 32 I ...

Page 147: ...ctor has the seal in place 5 Push the high pressure fuel line connector onto the fuel pump module fitting 6 If the Oetiker clamp was cut to remove the inlet fuel line slide a new Oetiker clamp onto the fuel line and connect the fuel line Only use an Oetiker clamp pliers to crimp Oetiker clamps The Oetiker clamp crimp must point up away from the top of the fuel pump module and the abrasion sleeve m...

Page 148: ... 2 Attach governor spring to the previously marked hole on the governor lever See Figure 10 80 Item Description 1 Bracket speed control 2 Clamp cable 3 Lever throttle control top 4 Lever throttle actuator bottom 5 Screw M5x0 8x20 6 Washer spring 7 Washer flat 2 8 Spring return 9 Nut M5x0 8 lock 1 1 2 2 3 4 4 5 5 9 8 7 6 Throttle Throttle Linkage Linkage Spring Spring Throttle Throttle Linkage Link...

Page 149: ...nge screws behind any control panel or bracket Attach the air cleaner base to the lower bracket with the two M5 screws through the lower section of the base Torque the hex flange nuts to 6 2 7 3 N m 55 65 in lb and the two lower M5 mounting screws when applicable to 4 0 N m 35 in lb See Figures 10 83 and 10 84 Figure 10 84 Low Profile Air Cleaner and Bracket 2 Install the air cleaner components as...

Page 150: ... to these specifications to prevent oil leakage Torque Nipple Torque Nipple Figure 10 85 Setting Initial Governor Adjustment Install Muffler 1 Install the port liners if equipped Install exhaust gaskets and the muffler Install the oxygen sensor torque to 50 1 N m 37 ft lb and connect to wire harness 2 Install the muffler and attaching hardware to the muffler bracket Torque screws to 9 9 N m 88 in lb 3 I...

Page 151: ...ic Fuel Injection System 5 Turn on fuel supply Sensitivity Adjustment Governor sensitivity is adjusted by repositioning the governor spring in the holes of the governor lever If speed surging occurs with a change in engine load the governor is set too sensitive If a big drop in speed occurs when normal load is applied the governor should be set for greater sensitivity See Figure 10 92 and adjust a...

Page 152: ...l pressure 20 psi or more is present Run the engine at idle for 2 3 minutes then 5 6 minutes more between idle and midrange 2 Adjust the idle speed screw located on the throttle body as necessary The standard idle speed setting for EFI engines is 1500 RPM but certain applications might require a different setting 3 Adjust the high speed stop as necessary located on the control panel if so equipped ...

Page 153: ......

Page 154: ...90 01 Rev C ISSUED 5 10 REVISED 11 10 FOR SALES AND SERVICE INFORMATION IN U S AND CANADA CALL 1 800 544 2444 KohlerEngines com ENGINE DIVISION KOHLER CO KOHLER WISCONSIN 53044 2010 by Kohler Co All rights reserved ...

Reviews:

No comments

Related manuals for Command PRO CH749

Brands by name

Popular brands

Load more brands