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American Standard 6065161.002 Indoor Furnishings User Manual

1. 5B 30 Fault Codes 5B 30 5B 38 Troubleshooting Flow Chart 5B 38 5B 39 Flow Chart Diagnostic Aids 5B 40 5B 41 EFI Service Tools Refer to Section 2 5B 2 Section 5B EFI Fuel System WARNING Explosive Fuel Gasoline is extremely flammable and its vapors can explode if ignited Store gasoline only in approved containers in well ventilated unoccupied buildings away from sparks or flames Do not fill the fuel tank while the engine is hot or running since spilled fuel could ignite if it comes in contact with hot parts or sparks from ignition Do not start the engine near spilled fuel Never use gasoline as a cleaning agent The EFI fuel system remains under high pressure even when the engine is stopped Before attempting to service any part of the fuel system the pressure must be relieved Pressure tester part of EFI
2. 6 025 6 050 mm 0 2372 0 2382 in Max Wear Limit 6 063 mm 0 2387 in 8 mm Shaft New 8 025 8 075 mm 0 3159 0 3179 in Max Wear Limit 8 088 mm 0 3184 in Breather Cover Fastener Torque 7 3 N m 65 in lb Oil Drain Plug Torque 13 6 N m 10 ft lb Oil Pan Oil Pan Fastener Torque 24 4 N m 216 in lb Crankshaft End Play Free 0 070 0 590 mm 0 0028 0 0230 in Crankshaft Bore In Crankcase New 40 965 41 003 mm 1 6128 1 6143 in Max Wear Limit 41 016 mm 1 6148 in Crankshaft to Sleeve Bearing Crankcase Ru
3. 0 030 0 080 mm 0 0012 0 0031 in CV18 CV20 CV22 624 cc 0 040 0 080 mm 0 0016 0 0031 in CV22 23 674 cc 0 030 0 076 mm 0 0012 0 0030 in CV25 CV26 CV730 750 0 015 0 037 mm 0 0006 0 0015 in Oil Control Ring to Groove Side Clearance CV17 0 046 0 201 mm 0 0018 0 0079 in CV18 CV20 CV22 624 cc 0 060 0 202 mm 0 0024 0 0080 in CV22 23 674 cc 0 046 0 196 mm 0 0018 0 0077 in CV25 CV26 CV730 750 0 026 0 176 mm 0 0010 0 0070 in 1 14 Section 1 Safety and General Information Piston Piston Rings and Piston Pin cont Top and Middle Compression Ring End Gap New Bore CV17 Top Ring 0 180 0 380 mm 0 0071 0 0150 in Middle Ring
4. 5B 19 5B 21 Fuel Filter 5B 21 Fuel Rail 5B 21 Fuel Line 5B 21 5B 22 Throttle Body Intake Manifold Assembly 5B 22 Idle Speed Adjustment RPM 5B 22 5B 23 Initial Governor Adjustment 5B 23 5B 25 Troubleshooting Troubleshooting Guide 5B 25 Electrical System 5B 25 5B 29 Fuel System
5. 69 mm 2 7 in Displacement CV17 561 cc 34 cu in CV18 CV20 CV22 624 cc 624 cc 38 cu in CV22 23 674 cc 674 cc 41 cu in CV25 CV26 CV730 745 725 cc 44 cu in CV750 755 cc 46 cu in Compression Ratio CV17 8 2 1 CV18 CV20 CV22 23 8 5 1 CV25 CV26 CV730 745 9 0 1 CV750 9 4 1
6. 2 1 4 5 3 5B 8 9 10 11 6 7 1 1 Section 1 Safety and General Information 1 Section 1 Safety and General Information Safety Precautions To ensure safe operation please read the following statements and understand their meaning Also refer to your equipment manufacturer s manual for other important safety information This manual contains safety precautions which are explained below Please read carefully WARNING Warning is used to indicate the presence of a hazard that can cause severe personal injury death or substantial property damage if the warning is ignored CAUTION Caution is used to indicate the presence of a hazard that will or can cause minor personal injury or property damage if the caution is ignored NOTE Note is used to notify people of installation operation or maintenance information that is important but not hazard related For Your Safety These precautions should be followed at all times Failure to follow these precautions could result in injury to yourself and others Rotating Parts can cause severe injury Stay away while engine is in operation WARNING Rotating Parts Keep hands feet hair and clothing away from all moving parts to prevent injury Never operate the engine with covers shrouds or guards removed Hot Parts can cause severe burns Do not touch engin
7. 0 025 mm 0 0010 in Connecting Rod Journal O D New 35 955 35 973 mm 1 4156 1 4163 in O D Max Wear Limit 35 94 mm 1 415 in Max Taper 0 018 mm 0 0007 in Max Out of Round 0 025 mm 0 0010 in Crankshaft T I R PTO End Crank in Engine 0 279 mm 0 0110 in Entire Crank in V Blocks 0 10 mm 0 0039 in 1 12 Section 1 Safety and General Information Cylinder Bore Cylinder Bore I D New CV17 73 006 73 031 mm 2 8742 2 8752 in New CV18 CV20 CV22 624 cc 77 000 77 025 mm 3 0315 3 0325 in New CV22 23 674 cc 80 000 80 025 mm 3 1496 3 1506 in New CV25 CV26 CV730 750
8. 19 4 kW 26 HP CV740 20 1 kW 27 HP CV745 20 9 kW 28 HP CV750 22 4 kW 30 HP Peak Torque CV17 2200 RPM 35 9 N m 28 7 ft lb CV18 2200 RPM 42 5 N m 31 4 ft lb CV20 2400 RPM 45 1 N m 33 3 ft lb CV22 2200 RPM 49 6 N m 36 6 ft lb CV23 2400 RPM 54 5 N m 40 2 ft lb CV25 CV730 2400 RPM
9. 27 N m 20 ft lb Piston Piston Rings and Piston Pin Piston to Piston Pin Running Clearance 0 006 0 017 mm 0 0002 0 0007 in Piston Pin Bore I D New 17 006 17 012 mm 0 6695 0 6698 in Max Wear Limit 17 025 mm 0 6703 in Piston Pin O D New 16 995 17 000 mm 0 6691 0 6693 in Max Wear Limit 16 994 mm 0 6691 in Top Compression Ring to Groove Side Clearance CV17 0 040 0 085 mm 0 0016 0 0033 in CV18 CV20 CV22 624 cc 0 040 0 080 mm 0 0016 0 0031 in CV22 23 674 cc 0 030 0 076 mm 0 0012 0 0030 in CV25 CV26 CV730 750 0 025 0 048 mm 0 0010 0 0019 in Middle Compression Ring to Groove Side Clearance CV17
10. 3 4 N m 30 in lb Black O Ring Style Cover w Shoulder Screws 5 6 N m 50 in lb w Flange Screws and Spacers 9 9 N m 88 in lb Yellow or Brown O Ring Style Cover w Integral Metal Spacers 6 2 N m 55 in lb Valves and Valve Lifters Hydraulic Valve Lifter to Crankcase Running Clearance 0 0241 0 0501 mm 0 0009 0 0020 in Intake Valve Stem to Valve Guide Running Clearance 0 038 0 076 mm 0 0015 0 0030 in Exhaust Valve Stem to Valve Guide Running Clearance 0 050 0 088 mm 0 0020 0 0035 in Intake Valve Guide I D New 7 038 7 058 mm 0 2771 0 2779 in Max Wear Limit 7 134 mm 0 2809 in Exhaust Valve Guide I D New 7 038 7 058 mm 0 2771 0 2779 in Max Wear Limit 7 159 mm 0 2819 in Valve Guide Reamer Size Standard
11. 4 5 7 5 N m 40 84 in lb Delco Remy Solenoid Shift 5 6 9 0 N m 49 79 in lb Mounting Screw Torque All 15 3 N m 135 in lb Brush Holder Mounting Screw Torque Delco Remy Starter 2 5 3 3 N m 22 29 in lb Solenoid Starter Mounting Hardware Torque Nippondenso Starter 6 0 9 0 N m 53 79 in lb Delco Remy Starter 4 0 6 0 N m 35 53 in lb Nut Positive Brush Lead Torque Nippondenso Starter 8 0 12 0 N m 71 106 in lb Delco Remy Starter 8 0 11 0 N m 71 97 in lb Measure 6 mm 0 236 in above the bottom of the piston skirt at right angles to the piston pin 1 15 Section 1 Safety and General Information 1 Stator Mounting Screw Torque 6 2 N m 55 in lb Valve Cover Valve Cover Fastener Torque Gasket Style Cover
12. 5B 9 5B 10 Oxygen Sensor 5B 10 5B 12 Electrical Relay 5B 12 5B 13 Fuel Injectors 5B 13 5B 16 Ignition System 5B 17 Spark Plugs 5B 18 Wiring Harness 5B 18 Battery Charging System 5B 18 Fuel Components Fuel Pump 5B 18 5B 19 Fuel Pressure Regulator
13. 82 986 mm 3 2671 in Max Wear Limit CV17 72 839 mm 2 8677 in Max Wear Limit CV18 CV20 CV22 624 cc 76 840 mm 3 0252 in Max Wear Limit CV22 674 cc 79 831 mm 3 1430 in Max Wear Limit CV25 CV26 CV730 750 82 841 mm 3 2614 in Piston Thrust Face to Cylinder Bore Running Clearance New CV17 0 022 0 065 mm 0 0009 0 0026 in New CV18 CV20 CV22 624 cc 0 014 0 057 mm 0 0005 0 0022 in New CV22 23 674 cc 0 021 0 062 mm 0 0008 0 0024 in New CV25 CV26 CV730 750 0 001 0 045 mm 0 039 0 0018 in Speed Control Bracket Fastener Torque 10 7 N m 95 in lb into new holes 7 3 N m 65 in lb into used holes Starter Assembly Thru Bolt Torque UTE Johnson Electric Eaton Inertia Drive 4 5 5 7 N m 40 50 in lb Nippondenso Solenoid Shift
14. 82 988 83 013 mm 3 2672 3 2682 in Max Wear Limit CV17 73 070 mm 2 8757 in Max Wear Limit CV18 CV20 CV22 624 cc 77 063 mm 3 0340 in Max Wear Limit CV22 23 674 cc 80 065 mm 3 1522 in Max Wear Limit CV25 CV26 CV730 750 83 051 mm 3 2697 in Max Out of Round CV17 0 13 mm 0 0051 in Max Out of Round CV18 750 0 12 mm 0 0047 in Max Taper 0 05 mm 0 0020 in Cylinder Head Cylinder Head Fastener Torque Hex Flange Nut Torque in Two Stages first to 16 9 N m 150 in lb finally to 33 9 N m 300 in lb Head Bolt Torque in Two Stages first to 22 6 N m 200 in lb finally to 41 8 N m 370 in lb Max Out of Flatness 0 076 mm 0 003 in Rocker Arm Screw Torque 11 3 N m 100 in lb Fan Flywheel Fa
15. 7 048 mm 0 2775 in 0 25 mm O S 7 298 mm 0 2873 in Intake Valve Minimum Lift 8 07 mm 0 3177 in Exhaust Valve Minimum Lift 8 07 mm 0 3177 in Nominal Valve Seat Angle 45 1 16 Section 1 Safety and General Information General Torque Values Metric Fastener Torque Recommendations for Standard Applications Tightening Torque N m in lb or 10 Property Class Noncritical Fasteners Into Aluminum Size 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 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 1 17 Section 1 Safety and General I
16. 0 180 0 440 mm 0 0071 0 0173 in New Bore CV18 CV20 CV22 624 cc 0 25 0 45 mm 0 0098 0 0177 in New Bore CV22 674 cc 0 18 0 46 mm 0 0071 0 0181 in New Bore CV25 CV26 CV730 750 0 25 0 56 mm 0 0100 0 0224 in Used Bore Max CV17 Top Ring 0 70 mm 0 028 in Middle Ring 0 90 mm 0 035 in Used Bore Max CV18 CV20 CV22 624 cc 0 77 mm 0 030 in Used Bore Max CV22 23 674 cc 0 80 mm 0 0315 in Used Bore Max CV25 CV26 CV730 750 0 94 mm 0 037 in Piston Thrust Face O D New CV17 72 966 72 984 mm 2 8727 2 8734 in New CV18 CV20 CV22 624 cc 76 967 76 985 mm 3 0302 3 0309 in New CV22 23 674 cc 79 963 79 979 mm 3 1481 3 1488 in New CV25 CV26 CV730 750
17. should again be obtained Figure 5B 4 Speed Sensor Connector 7 a If the resistance is incorrect remove the screw securing the sensor to the mounting bracket and replace the sensor b If the resistance in step 5 was incorrect but the resistance of the sensor alone was correct test the main harness circuits between the sensor connector terminals and the corresponding pin terminals 9 and 10 in the main connector Correct any observed problem reconnect the sensor and perform step 5 again Throttle Position Sensor TPS Dual Aligning Rails Test Terminals Corresponds To 10 Pin Terminal In Main Connector Corresponds To 9 Pin Terminal In Main Connector 1 2 3 4 1 Throttle Valve Shaft 2 Resistor Track 3 Wiper Arm With Wiper 4 Electrical Connection Figure 5B 5 Throttle Position Sensor Details 5B 7 Section 5B EFI Fuel System 5B General The throttle position sensor TPS is used to indicate throttle plate angle to the ECU Since the throttle by way of the governor reacts to engine load the angle of the throttle plate is directly related to the load on the engine Figure 5B 6 TPS Location Mounted on the throttle body intake manifold and operated directly off the end of the throttle shaft the TPS works like a rheostat varying the voltage signal to the ECU in direct correlation to the angle of the throttle plate This signal along with the other sensor sign
18. 22 7 N m 200 in lb 8 mm step down 14 7 N m 130 in lb 6 mm straight shank 11 3 N m 100 in lb Connecting Rod to Crankpin Running Clearance New 0 030 0 055 mm 0 0012 0 0022 in Max Wear Limit 0 070 mm 0 0028 in Connecting Rod to Crankpin Side Clearance 0 26 0 63 mm 0 0102 0 0248 in Connecting Rod to Piston Pin Running Clearance 0 015 0 028 mm 0 0006 0 0011 in Piston Pin End I D New 17 015 17 023 mm 0 6699 0 6702 in Max Wear Limit 17 036 mm 0 6707 in 1Values are in Metric units Values in parentheses are English equivalents Lubricate threads with engine oil prior to assembly 1 11 Section 1 Safety and General Information 1 Crankcase Governor Cross Shaft Bore I D 6 mm Shaft New
19. 55 6 N m 41 0 ft lb CV26 2800 RPM 54 2 N m 40 0 ft lb CV740 2800 RPM 56 9 N m 42 0 ft lb CV745 2400 RPM 60 0 N m 44 3 ft lb CV750 2600 RPM 63 8 N m 47 1 ft lb Bore CV17 73 mm 2 87 in CV18 CV20 CV22 624 cc 77 mm 3 03 in CV22 23 674 cc 80 mm 3 15 in CV25 CV26 CV730 750 83 mm 3 27 in Stroke CV17 745 67 mm 2 64 in CV750
20. Disassembly and Section 11 Reassembly if stator replacement is necessary Rectifier Regulator The rectifier regulator is mounted on the blower housing See Figure 8 24 To replace it disconnect the plug s remove the two mounting screws and ground wire or metal grounding strap NOTE When installing the rectifier regulator take note of the terminal markings and install the plug s accordingly Figure 8 24 Rectifier Regulator Testing of the rectifier regulator may be performed as follows using the appropriate Rectifier Regulator Tester see Section 2 To Test NOTE Disconnect all electrical connections attached to the rectifier regulator Testing may be performed with the rectifier regulator mounted or loose The figures show the part removed from the engine for clarity Repeat the applicable test procedure two or three times to determine the condition of the part 15 Amp Rectifier Regulators 1 Connect the tester ground lead with spring clamp to the body of the rectifier regulator being tested 2 Connect the tester red lead to the B terminal of the rectifier regulator and the two black tester leads to the two AC terminals See Figure 8 25 Figure 8 25 Ground Strap or lead Rectifier Regulator Lighting Lead Yellow Charging Lead Black Diode Lighting Stator 3 Amp Charging Stator 8 19 8 Section 8 Electrical System and Components 3 Plug the tester into t
21. 9 Recheck regulated system pressure at fuel rail test valve Fuel Filter EFI engines use a high volume high pressure 10 15 micron in line fuel filter Figure 5B 29 In Line Fuel Filter Service Filter replacement is recommended every 1500 hours of operation or more frequently under extremely dusty or dirty conditions Use only the specified filter and install it according to the directional arrows Do not use a substitute filter as operating performance and safety can be affected Relieve system pressure through the safety valve in the fuel rail before servicing Figure 5B 30 Throttle Body Intake Manifold General The fuel rail is a formed tube assembly that feeds fuel to the top of the injectors The tops of the injectors fit into formed cups in the fuel rail When the rail is fastened to the manifold the injectors are locked into place A small retaining clip provides a secondary lock Incorporated into the fuel rail is a pressure relief test valve for testing operating pressure or relieving fuel system pressure for servicing The fuel supply line is attached to the barbed end of the fuel rail with an Oetiker hose clamp Service The fuel rail is mounted to the throttle body intake manifold No specific servicing is required unless operating conditions indicate that it needs internal cleaning or replacement It can be detached by removing the two mounting screws and the injector retaining clips Thoroughly clean the
22. Figure 6 9 Oil Sentry Location On engines not equipped with Oil Sentry the installation hole is sealed with a 1 8 27 N P T F pipe plug To install the switch follow these steps 1 Apply pipe sealant with Teflon Loctite No 59241 or equivalent to the threads of the switch 2 Install the switch into the tapped hole in the breather cover See Figure 6 9 3 Torque the switch to 4 5 N m 40 in lb Testing the Switch Compressed air a pressure regulator pressure gauge and a continuity tester are required to test the switch 1 Connect the continuity tester across the blade terminal and the metal case of the switch With 0 psi pressure applied to the switch the tester should indicate continuity switch closed 2 Gradually increase the pressure to the switch As pressure increases through the range of 3 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 3 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 not operate as specified Figure 6 8 Cleaning Blower Housing Mounted Oil Cooler Oil Sentry General Some engines are equipped with an optional Oil Sentry oil pressure monitor switch If the oil pressure drops below an acceptable level the Oil Sen
23. Figure 8 68 Removing Retaining Clips b Position each of the brushes back in their slots so they are flush with the I 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 8 69 Figure 8 67 Installing Brush Holder Assembly with Supplied Tube Starter reassembly when not replacing the Brushes Brush Holder Assembly a Carefully unhook the retaining caps from over each of the brush assemblies Do not lose the springs Figure 8 69 Brush Installation Tool with Extension d Hold the starter assembly vertically on the end housing and carefully place the tool with extension and assembled original brush holder assembly onto the end of the armature shaft Slide the brush holder assembly down into place around the commutator install the positive brush lead grommet in the cutout of the frame See Figure 8 70 8 38 Section 8 Electrical System and Components Figure 8 70 Installing Brush Holder Assembly using Tool with Extension 11 Install the end cap onto the armature and frame aligning the thin raised rib in the end cap with the corresponding slot in the grommet of the positive brush lead 12 Install the two thru bolts and the two brush h
24. When the light starts blinking rapidly 5 blinks per second move the throttle lever to the low idle speed position Check and adjust the idle speed to 1500 RPM using a tachometer The lamp should continue to blink rapidly for another 30 seconds before switching to a slow blink 8 When the MIL blinks slowly do not do anything but wait until the MIL shuts off This indicates that this procedure has been completed successfully 9 Shut off the engine If the learn procedure was successfully completed the external loads removed disconnected in Step 2 may be reconnected If the procedure was unsuccessful see Steps a and b following a If the MIL goes back to blinking 4 consecutive blinks every 2 seconds during the procedure the engine and O2 sensor have cooled down and gone out of closed loop operation prohibiting the learning from occurring Repeat Steps 6 9 b If the MIL stays on continuously for more than 15 seconds during the procedure there is probably a fault code present turn off the ignition Then initiate the fault code sequence by turning the key switch on off on off on leaving the key on in the last sequence each key on off sequence must be less than 2 5 seconds long The fault detected must be corrected before the auto learn function can be re initiated The PC based diagnostic software may be used to read out the fault code and assist with troubleshooti
25. Change Oil and Oil Filter in Section 6 3 The fuel system must be completely emptied or the gasoline must be treated with a stabilizer to prevent deterioration If you choose to use a stabilizer follow the manufacturer s recommendations and add the correct amount for the capacity of the fuel system Fill the fuel tank with clean fresh gasoline Run the engine for 2 to 3 minutes to get stabilized fuel into the rest of the system Close the fuel shut off valve when the unit is being stored or transported To empty the system run the engine until the tank and the system is empty 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 On equipment with an EFI engine disconnect the battery or use a battery minder to keep the battery charged during storage 6 Store the engine in a clean dry place Periodic Maintenance Instructions WARNING Accidental Starts Disabling engine Accidental starting can cause severe injury or death Before working on the engine or equipment disable the engine as follows 1 Disconnect the spark plug lead s 2 Disconnect negative battery cable from battery Maintenance Schedule These required maintenance procedures should be performed at the frequency stated in the table They should also be included as part of any seasonal tune up
26. Dry Weight CV17 CV18 CV20 CV22 23 41 kg 90 lb CV25 CV26 CV730 745 43 kg 94 lb CV750 48 kg 105 lb 1Values are in Metric units Values in parentheses are English equivalents Lubricate threads with engine oil prior to assembly 1 10 Section 1 Safety and General Information General Specifications1 cont Oil Capacity w filter approximate determined by oil filter and oil cooler used 1 6 1 8 L 1 7 1 9 U S qt Angle of Operation Maximum At Full Oil Level All Directions 25 Blower Housing and Sheet Metal 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 Rectifier Regulator Fastener Torque 1 4 N m 12 6 in lb
27. Electronic CD Ignition System including SMART SPARK on applicable models Electric Starter Spark Plugs Engine misfire or starting problems are often caused by a spark plug that has improper gap or is in poor condition The engine is equipped with the following spark plugs Type The standard spark plug is a Champion RC12YC Kohler Part No 12 132 02 S RFI compliant engines use a Champion XC12 YC Kohler 25 132 14 S spark plug A high performance spark plug Champion Platinum 3071 used on Pro Series engines Kohler Part No 25 132 12 S is also available Equivalent alternate brand plugs can also be used Gap 0 76 mm 0 030 in Thread Size 14 mm Reach 19 1 mm 3 4 in Hex Size 15 9 mm 5 8 in Spark Plug Service Remove the spark plugs after 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 NOTE Do not clean spark plugs in a machine using abrasive grit Some grit could remain in the spark plug and enter the engine causing extensive wear and damage 3 Check the gap using a wire feeler gauge Adjust the gap to 0 76 mm 0 030 in by
28. Figure 8 29 5 Plug the tester into the proper AC outlet power supply for tester being used Turn on the power switch The POWER light should be illuminated and one of the four status lights may be on as well See Figure 8 26 This does not represent the condition of the part 8 20 Section 8 Electrical System and Components 6 Press the TEST button until a click is heard and then release See Figure 8 27 Momentarily one of the four status lights will illuminate indicating the partial condition of the part a If the OK green light comes on disconnect the tester black lead attached to one AC terminal and reconnect it to the other AC terminal Repeat the test If the OK green light comes on again the part is good and may be used b If any other light is displayed in either of the tests the rectifier regulator is faulty and should not be used NOTE A flashing LOW light can also occur as a result of an inadequate ground lead connection Make certain the connection location is clean and the clamp is secure 25 Amp Rectifier Regulators Original Style 1 Connect the squared single end of the tandem lead adapter to the B center red lead of the rectifier regulator being tested See Figure 8 30 Figure 8 30 2 Connect the ground lead of tester with spring clamp to the housing of rectifier regulator 3 Connect the red lead and one o
29. 2 Disconnect the pulse vacuum hose from the crankcase See Figure 9 16 3 Remove the two hex flange mounting screws from the blower housing and remove the fuel pump and lines as an assembly See Figure 9 17 Remove Throttle Controls 1 Remove the four hex flange screws securing the throttle control bracket and lower air cleaner bracket some models to the cylinder heads See Figures 9 18 and 9 19 Fuel Pump Outlet Hose To Carburetor Inlet Hose Pulse Hose Mounting Screws Figure 9 16 Disconnecting Pulse Line from Crankcase Pulse Hose 9 6 Section 9 Disassembly Figure 9 18 Removing Control Bracket Figure 9 19 Removing Control Bracket and Air Cleaner Bracket Some Models 2 Disconnect the spring from the governor lever note hole locations for reassembly 3 Remove the choke linkage from the choke actuator lever and carburetor Remove External Governor Controls 1 Loosen the hex flange nut and remove the governor lever from the cross shaft See Figure 9 20 Leave the lever attached to the throttle linkage Figure 9 20 Removing Governor Lever Remove Carburetor WARNING Explosive Fuel Gasoline may be present in the carburetor and fuel system Gasoline is extremely flammable and its vapors can explode if ignited Keep sparks and other sources of ignition away from the engine 1 Disconnect the fuel shut off solenoid lead if so equipped Control Bracket Air Cleaner Brackets
30. Float Valve Main Jet Float Main Emulsion Hole Idle Speed RPM Adjustment Screw Air Fuel Mixture Main Circuit See Figure 5 4 At high speeds loads the engine operates on the main circuit As a metered amount of air is drawn through the main air bleed jet fuel is drawn through the main jet The air and fuel are mixed in the main nozzle and then enter the main body of airflow where further mixing of the fuel and air takes place This mixture is then delivered to the combustion chamber The carburetor has a fixed main circuit no adjustment is possible 5 7 Section 5 Fuel System and Governor 5 Troubleshooting Checklist When the engine starts hard runs roughly or stalls at low idle speed check the following areas before adjusting or disassembling the carburetor Make sure the fuel tank is filled with clean fresh gasoline Make sure the fuel tank cap vent is not blocked and that it is operating properly Make sure fuel is reaching the carburetor This includes checking the fuel shut off valve fuel tank filter screen in line fuel filter fuel lines and fuel pump for restrictions or faulty components as necessary Make sure the air cleaner base and carburetor are securely fastened to the engine using gaskets in good condition Make sure the air cleaner element including the precleaner if equipped is clean and all air cleaner components are fastened securely Make
31. If the cylinder bore does not need reboring and if the old piston is within wear limits and free of score or scuff marks the old piston may be reused 3 Remove the old rings and clean up the grooves Never reuse old rings 4 Before installing the new rings on the piston place the top two rings each in turn in its running area in the cylinder bore and check the end gap See Figure 10 9 Compare the ring gap to the specifications listed in Section 1 Figure 10 9 Measuring Piston Ring End Gap 5 After installing the new compression top and middle rings on the piston check the piston to ring side clearance Compare the clearance to specifications listed in Section 1 If the side clearance is greater than specified a new piston must be used Refer to Figure 10 10 Figure 10 11 Installing Piston Rings Piston Ring Piston Ring Expander 10 11 Section 10 Inspection and Reconditioning 10 Figure 10 12 Piston Ring Installation 1 Oil Control Ring Bottom Groove Install the expander and then the rails Make sure the ends of the expander are not overlapped 2 Middle Compression Ring Center Groove Install the center ring using a piston ring expander tool Make sure the identification mark is up or the dykem stripe if contained is to the left of the end gap 3 Top Compression Ring Top Groove Install the top ring using a piston ring expander Make sure the identification mark is up
32. Some Models Control Bracket Governor Lever Figure 9 21 Removing Fuel Solenoid and Ground Leads Two Barrel Model Pictured 2 Remove the carburetor mounting nuts See Figure 9 21 Fuel Solenoid Lead Ground Lead 9 7 Section 9 Disassembly 9 3 Remove the carburetor throttle linkage and governor lever as an assembly Figure 9 22 Removing Carburetor and Linkage Two Barrel Model Pictured Figure 9 23 Removing Carburetor Mounting Nuts Commercial Mower Base Shown 5 If necessary the carburetor throttle linkage and governor lever can be separated Reattach the bushings to the linkage following separation to avoid losing them Remove Electric Starter Motor 1 Disconnect the leads from the starter 2 Remove the two hex flange screws See Figure 9 25 Figure 9 25 Removing Electric Starter Motor 3 Remove the starter assembly and lift bracket Some inertia drive starters use a separate starter cover and spacers Figure 9 24 Removing Carburetor 4 Remove the carburetor gasket 9 8 Section 9 Disassembly Figure 9 29 Removing Outer Baffles 5 If the flywheel screen overlaps the blower housing remove the fasteners and screen If it was a metal screen with long bolts also remove the remaining loose hardware and cooling fan See Figure 9 30 Figure 9 27 Loosening Spark Advance Module Applicable Models Figure 9 28 Note Location of Short Screws 4 Remove the outer ba
33. Spitback Cup Air Cleaner Base Figure 4 5 Air Cleaner System Components Standard Figure 4 6 Air Cleaner System Components Commercial Mower Type 4 4 Section 4 Air Cleaner and Air Intake System 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 the stud hole Air Cleaner Base Make sure the base is secured tightly to the carburetor and not cracked or damaged Breather Tube Make sure the tube is attached to both the air cleaner base and the oil separator NOTE Damaged worn or loose air cleaner components can allow unfiltered air into the engine causing premature wear and failure Tighten or replace all loose or damaged components Figure 4 7 Base Plate Removal on Standard Type Disassembly Reassembly Standard Type If the base plate on the standard type has to be removed proceed as follows 1 Remove the air cleaner components from the base see Figure 4 5 2 Remove the two hex flange nuts securing the bracket or spitback cup with seal and baffle if equipped to base If a plastic intake manifold is used remove the two lower base mounting screws See Figure 4 7 3 Pinch the sealing collar on the breather hose and push it down th
34. center terminal of the rectifier and the two black tester leads to the two AC outside terminals See Figure 8 32 8 21 8 Section 8 Electrical System and Components Figure 8 33 Connections for Testing Charging System Figure 8 32 3 Plug the tester into the proper AC outlet power supply for tester being used Turn on the power switch The POWER light should be illuminated and one of the four status lights may be on as well See Figure 8 26 This does not represent the condition of the part 4 Press the TEST button until a click is heard and then release See Figure 8 27 Momentarily either the HIGH LOW or SHORT light will flash a If the HIGH light flashes on off the part is good and may be used b If any other light is displayed the rectifier is faulty and should not be used NOTE A flashing LOW light can also occur as a result of an inadequate ground lead connection Make certain connection location is clean and clamp is secure DC Voltmeter Rectifier Regulator Flywheel Stator Ammeter Battery 8 22 Section 8 Electrical System and Components Problem Test Conclusion 1 Trace B lead from rectifier regulator to key switch or other accessible connection Disconnect it from switch or connection Connect an ammeter from loose end of B lead to positive terminal of battery Connect DC voltme
35. go to Step 5 5B 12 Section 5B EFI Fuel System b If the resistance is less than 1 0 M the sensor is bad replace it 5 With the oxygen sensor disconnected and engine not running disconnect the main harness connector from the ECU and set the meter to the Rx1 scale Check the circuit continuity as follows 24 Pin MSE 1 0 Plastic Cased ECU Check for continuity from pin 15 of the ECU connector see page 5B 26 to the shell of the oxygen sensor and from pin 11 to the sensor connector terminal of the main harness Both tests should indicate continuity 32 Pin MSE 1 1 Plastic Cased ECU Check for continuity from pin 19 of the ECU connector see page 5B 29 to the shell of the oxygen sensor and from pin 20 to the sensor terminal of the main harness Both tests should indicate continuity a If there is no continuity displayed in either of the tests check the harness circuit for breaks or damage and the connections for poor contact moisture or corrosion If no continuity was found in the first test also check for a poor broken ground path back through the exhaust system engine and mounting sensor is grounded through its shell b If continuity is indicated go to step 6 6 With the key switch in the on run position using a high impedance voltmeter check the voltage from the wiring harness oxygen sensor connector to the engine ground location Look for a ste
36. 3240 3132 3024 3600 3500 3400 3300 3200 3100 3000 2900 2800 Orange Black Red Green Red Green Blue Clear Clear 3 3 3 2 2 1 1 1 1 Standard Throttle Control With WAWB Wide Area Walk Behind Throttle Control Spring Color Hole No Red Purple Blue Orange Green Red Purple Blue Clear 3 3 3 2 2 1 1 1 1 8 mm Governor Lever and Hole Position RPM Charts cont Figure 11 79 Installing Starter and Lift Bracket Lift Bracket Dipstick Tube Support Starter CV750 Engines Governor Shaft Configuration High Idle WOT Intended Maximum RPM Spring Color Hole No Standard Parent Material 3888 3780 3672 3564 3456 3348 3600 3500 3400 3300 3200 3100 Clear Orange Blue Red Clear Clear 3 1 1 1 1 1 With Governed Idle Systems Figure 11 80 Installing Dipstick Tube 4 Install the dipstick tube and align the mounting hole with the threaded hole in the lift bracket Secure with the M5 hex flange screw Torque the screw to 4 0 N m 35 in lb See Figure 11 80 11 26 Section 11 Reassembly Figure 11 81 Reinstalled Fuel Pump 2 Install the fuel pump using the two hex flange screws Torque the screws to 2 3 N m 20 in lb Figure 11 83 Installing Fuel Line Commercial Mower Shown Install Air Cleaner Assembly Refer to Section 4 for the air cleaner reassembly procedure Standard Air Cleaners 1 Connect the breather hose and attach the br
37. 7 5 3 5 2 r el h o K e s a e r G cirtc e l e i D o r P le F le S ir b u L t n a cir b u L e v ir D r e tr a t S cirtc e l E e v ir D aitr e n I S 1 0 7 5 3 2 5 r el h o K t n a cir b u L e v ir D r e tr a t S cirtc e l E tfi h S d io n elo S S 2 0 7 5 3 2 5 r el h o K t n a l a e S e n o cili S V T R etitc o L r e s n e p si d lo s o r e a z o 4 n i y d o B y v a e H 0 0 9 5 e s u r o f d e v o r p p a e r a d etsil e s o h t s a h c u s st n ala e s V T R t n a tsis e r lio d e s a b e m ix o y l n O etitc o L s citsir etc a r a h c g n ila e s ts e b r o f d e d n e m m o c e r e r a 0 1 9 5 r o 0 0 9 5 s o N etitc o L 0 1 9 5 etitc o L 8 9 5 k c al B a rtl U etitc o L 7 8 5 e u l B a rtl U etitc o L r e p p o C a rtl U S 7 0 7 9 5 5 2 r el h o K t n a cir b u L e v ir D e n il p S S 2 1 7 5 3 5 2 r el h o K 2 4 Section 2 Tools amp Aids Special Tools You Can Make Flywheel Holding Tool A flywheel holding tool can be made out of an old junk flywheel ring gear as shown in Figure 2 1 and used in place of a strap wrench 1
38. At the engine fuel is fed through the fuel rail and into the injectors which inject it into the intake ports The ECU controls the amount of fuel by varying the length of time that the injectors are on This can range from 1 5 8 0 milliseconds depending on fuel requirements The controlled injection of the fuel occurs each crankshaft revolution or twice for each 4 stroke cycle One half the total amount of fuel needed for one firing of a cylinder is injected during each injection When the intake valve opens the fuel air mixture is drawn into the combustion chamber ignited and burned The ECU controls the amount of fuel being injected and the ignition timing by monitoring the primary sensor signals for engine temperature speed RPM and throttle position load These primary signals are compared to preprogrammed maps in the ECU computer chip and the ECU adjusts the fuel delivery to match the mapped values After the engine reached operating temperature an exhaust gas oxygen sensor provides feedback to the ECU based upon the amount of unused oxygen in the exhaust indicating whether the fuel mixture being delivered is rich or lean Based upon this feedback the ECU further adjusts fuel input to re establish the ideal air fuel ratio This operating mode is referred to as closed loop operation The EFI system operates closed loop when all three of the following conditions are met a The oil temperature is gre
39. B Figure 8 34 Inertia Drive Electric Starter Dust Cover Drive Nut Collar Dust Cover Spacer Retaining Ring Anti Drift Spring Drive Pinion Dust Cover Stop Nut Stop Gear Spacer Anti Drift Spring Dust Cover Spacer Drive Pinion Spring Retainer 8 26 Section 8 Electrical System and Components Figure 8 36 Assembling Inner Half of Tool Around Armature Shaft and Retaining Ring 5 Thread the center screw into the removal tool until you feel resistance Use a wrench 1 1 8 or adjustable to hold the base of the removal tool Use another wrench or socket 1 2 or 13 mm to turn the center screw clockwise see Figure 8 37 The resistance against the center screw will tell you when the retaining ring has popped out of the groove in the armature shaft Style B Drive Service 1 The rubber dust cover has a molded lip on the inside that snaps into a groove in the dust cover spacer see Figure 8 35 Turn the drive pinion clockwise until it reaches the fully extended position While holding it in the extended position grasp the tip of the dust cover with a pliers or vise grip and pull it free from the spacer Dust Cover Retaining Ring Anti Drift Spring Drive Pinion Drive Nut Collar Dust Cover Spacer Spring Retainer Figure 8 35 Drive Components Bonded Inertia Drive Starter 2 Disassemble the snap ring removal tool see Section 2 3 Again r
40. Float Circuit The fuel level in the bowl is maintained by the float and fuel inlet needle The buoyant force of the float stops fuel flow when the engine is at rest When fuel is being consumed the float will drop and fuel pressure will push the inlet needle away from the seat allowing more fuel to enter the bowl When demand ceases the buoyant force of the float will again overcome the fuel pressure rising to the predetermined setting and stop the flow Slow amp Mid Range Circuit At low speeds the engine operates only on the slow circuit As a metered amount of air is drawn through the slow air bleed jets fuel is drawn through the two main jets and further metered through the slow jets Air and fuel are mixed in the body of the slow jet and exit to the transfer port From the transfer port the air fuel mixture is delivered to the idle progression chamber From the idle progression chamber the air fuel mixture is metered through the idle port passages At low idle when the vacuum signal is weak the air fuel mixture is controlled by the setting of the idle fuel adjusting screws This mixture is then mixed with the main body of air and delivered to the engine As the throttle plate opening increases greater amounts of air fuel mixture are drawn in through the fixed and metered idle progression holes As the throttle plate opens further the vacuum signal becomes great enough so the main circuit begins to work Main High Speed Circ
41. If fuel is not visible after 10 seconds stop cranking and allow the starter to cool for 60 seconds Fuel Recommendations General Recommendations Purchase gasoline in small quantities and store in clean approved containers An approved container with a capacity of 2 gallons or less with a pouring spout is recommended Such a container is easier to handle and helps prevent spillage during refueling 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 Do not use leaded gasoline as component damage will result Any costs damages incurred as a result of using leaded fuel will not be warranted Use only clean fresh unleaded gasoline with a pump sticker octane rating of 87 or higher In countries using the Research method it should be 90 octane minimum Explosive Fuel can cause fires and severe burns Fuel system ALWAYS remains under HIGH PRESSURE WARNING 5B 3 Section 5B EFI Fuel System 5B Gasoline Alcohol blends Gasohol up to 10 ethyl alcohol 90 unleaded gasoline by volume is approved as a fuel for Kohler EFI engines Other gasoline alcohol blends are not approved Gasoline Ether blends Methyl Tertiary Butyl Ether MTBE and unleaded gasoline blends up to a maximum of 15 MTBE by volume are approved a
42. L r e d n il y C n r o w e r a s e v la v r o s g n ir n o tsi p r e d n il y c fi d n a n oit n ete r n oits u b m o c g n i k c e h c r o F S 5 0 1 6 7 5 2 r el h o K e r a w tf o S cits o n g a i D I F E n o itc e j n I l e u F ci n o rtc e l E C P p o t k s e D r o p o t p a L h ti w e s U S 3 2 1 6 7 5 2 r el h o K I F E ti K e ci v r e S e n i g n e I F E n a p u g n itte s d n a g n it o o h s el b u o rt r o F S 1 0 1 6 7 4 2 r el h o K el b alia v A st n e n o p m o C la u d iv i d n I r ets e T e r u ss e r P t h g i L d io N r et p a d A 0 9 sr eil P p m al C r e k ite O e ri W d e R g u l P e d o C e ri W e u l B g u l P e d o C c n I y g olo n h c e T n g is e D 9 1 0 I T D 1 2 0 I T D 3 2 0 I T D 5 2 0 I T D 7 2 0 I T D 9 2 0 I T D s e ir e S S C l o o T g n i d l o H l e e h w y l F 7 0 4 2 8 R L K slo o T E S r e ll u P l e e h w y l F e n i g n e m o rf le e h w y lf e v o m e r o T 8 0 4 2 8 R L K slo o T E S 2 2 Section 2 Tools amp Aids t n o c
43. Purple Black Red Purple Black Red Clear Red Green 4 4 4 3 3 3 3 2 1 3888 3780 3672 3564 3456 3348 3240 3132 3024 3600 3500 3400 3300 3200 3100 3000 2900 2800 Green Blue Orange Clear Red Purple Blue Orange Black 4 4 3 4 3 2 2 1 1 CV17 CV20 740 Engines Without Throttle Limiter Engine Mounted Throttle Control Pivot Shaft Spring Color Hole No Standard Throttle Control High Idle WOT Intended Maximum RPM Spring Color Hole No Blue Orange Black Orange Green Blue Orange Black Red 4 3 3 2 2 2 1 1 1 3888 3780 3672 3564 3456 3348 3240 3132 3024 3600 3500 3400 3300 3200 3100 3000 2900 2800 Red Purple Black Red Purple Blue Orange Clear Red 4 3 3 3 2 2 1 2 1 4 3 2 1 Governor Lever 11 25 Section 11 Reassembly 11 Install Electric Starter Motor 1 Install the starter motor using the two hex flange screws Position the lift bracket as shown to also secure the dipstick tube See Figure 11 79 Some inertia drive starters have a pinion cover and spacers on the starter bolts 2 Torque the two hex flange screws to 15 3 N m 135 in lb 3 On models with a solenoid shift starter connect the leads to the solenoid CV26 CV745 EFI Engines Governor Shaft Configuration High Idle WOT Intended Maximum RPM Spring Color Hole No Standard Parent Material 3888 3780 3672 3564 3456 3348
44. Restricted return line causing excessive fuel pressure b Fuel inlet screen plugged in tank fuel pump only c Incorrect fuel pressure at fuel rail 2 Oxygen Sensor Related a Sensor connector or wiring problem b Sensor contaminated or damaged c Exhaust leak d Poor ground path e Pin circuit wiring or connectors Pin 11 for 24 Pin MSE 1 0 Plastic Cased ECU Pin 20 for 32 Pin MSE 1 1 Plastic Cased ECU 3 TPS Sensor Related a Throttle plate position incorrectly set or registered during Initialization b TPS problem or malfunction 4 Engine Wiring Harness Related a Difference in voltage between sensed voltage pin circuit 17 for metal cased ECU pin circuit 2 for plastic cased ECU and actual injector voltage circuit 45 45A 5 Systems Related a Ignition spark plug plug wire ignition coil b Fuel fuel type quality injector fuel pump fuel pressure c Combustion air air cleaner dirty restricted intake leak throttle bores d Base engine problem rings valves e Exhaust system leak f Fuel in the crankcase oil g Blocked or restricted fuel return circuit to tank 6 ECU Related a ECU to harness connection problem Code 34 Source Oxygen Sensor Fuel System Components Explanation Long term fuel adaptation control is at the upper or lower limit Expected Engine Response System operates closed loop No appreciable performance loss as long as th
45. The latest design uses a yellow or brown O Ring and the bolt hole spacers are molded in place 1 Remove the four hex flange screws securing each valve cover Note valve cover differences for proper location in reassembly 2 The O Ring type covers should lift off without prying If loose spacers are present save them With the gasket type break the seal by carefully prying under the edges of the cover Figure 9 35 Break Breather Cover Seal 5 Remove the breather cover and gasket if used See Figure 9 36 9 11 Section 9 Disassembly 9 Figure 9 39 Position of Ignition Modules 3 Remove the mounting screws and ignition modules Note the position of the ignition modules Remove Intake Manifold 1 Remove the four hex flange screws securing the intake manifold to the cylinder heads Note which screws hold the wiring clamps 2 Remove the intake manifold and the intake manifold gaskets aluminum intake manifolds or O Ring plastic intake manifolds See Figure 9 40 3 Leave the wiring harness attached to the manifold Figure 9 40 Removing Intake Manifold Remove Spark Plugs 1 Remove the spark plug from each cylinder head See Figure 9 41 Figure 9 41 Removing Spark Plugs Aluminum Intake Manifold Plastic Intake Manifold 9 12 Section 9 Disassembly Figure 9 43 Removing Cylinder Head 4 Remove the lifters from the lifter bores Use a hydraulic lifter tool Do not use a magnet
46. Then trace the power source circuit back through the harness key switch etc looking for any poor connections or faulty circuits 2 Disconnect all of the SAM leads isolating it from the engine Test the SAM according to style with tester 25 761 21 S tests ASAM style modules only or tester 25 761 40 S tests both ASAM and DSAM style modules Use the test instructions following or those provided with the tester If the SAM tests bad replace it 3 Reattach the SAM leads verifying a snug fit at the ignition module terminals If any connections do not feel snug disconnect the lead lightly pinch the female terminal with a pliers and recheck the fit 4 Seal the base of the ignition module connections with GE Novaguard G661 see Section 2 or Fel Pro Lubri Sel dielectric compound The beads should overlap between the two connections to form a solid bridge of compound Do not put any compound inside the connectors The 24 584 15 S ignition modules have a separator barrier between the terminals On these modules seal the base of the terminal if any portion of it is exposed but it is not necessary to have overlapping beads of sealant between the connections 5 Test for spark Test 2 to be sure the system is working before you reinstall the blower housing If there is still a spark problem on one side replace that ignition module and recheck spark To Test Using 25 761 21 S Tester ASAM only Test Proc
47. assembly is spring loaded Check to make sure the plate moves freely and is not binding affecting idle fuel delivery 4 Low Idle Speed Setting Place the throttle control into the idle or slow position Set the low idle speed to 1200 RPM 75 RPM by turning the low idle speed adjusting screw in or out Check the speed using a tachometer NOTE The actual low idle speed depends on the application Refer to the equipment manufacturer s recommendations The low idle speed for basic engines is 1200 RPM To ensure best results when setting the low idle fuel needle the low idle speed should be 1200 RPM 75 RPM 5 Low Idle Fuel Needle Setting Place the throttle into the idle or slow position Turn the low idle fuel adjusting needle in slowly until engine speed decreases and then back out approximately 3 4 to 1 turn to obtain the best low speed performance 6 Recheck the idle speed using a tachometer and readjust the speed as necessary Models with Governed Idle System An optional governed idle control system is supplied on some engines The purpose of this system is to maintain a desired idle speed regardless of ambient conditions temperature parasitic load etc that may change Engines with this feature contain a small secondary spring connected between the governor lever and the lower adjustment tab of the main bracket See Figure 5 7 The system requires an additional procedure for sett
48. available bearing grease Reassembly 1 Make sure the spring is well lubricated with grease Place the spring and keeper assembly into the pulley with spring toward pulley See Figure 7 7 2 Install the pulley assembly into the starter housing See Figure 7 8 Make sure the pulley is fully seated against the starter housing Do not wind the pulley and recoil spring at this time Figure 7 9 Installing Pawls and Pawl Springs 4 Place the brake washer in the recess in the starter pulley over the center shaft 5 Lubricate the brake spring sparingly with grease Place the spring on the washer Make sure the threads in the center shaft remain clean dry and free of grease and oil 6 Apply a small amount of Loctite No 271 to the threads of the center screw Install the center screw with washer and retainer to the center shaft Torque the screw to 7 4 8 5 N m 65 75 in lb 7 Tension the spring and install the rope and handle as instructed in steps 6 through 12 under Rope Replacement on page 7 2 8 Install the starter to the engine blower housing as instructed in To Install Starter on page 7 1 8 1 8 Section 8 Electrical System and Components Section 8 Electrical System and Components This section covers the operation service and repair of the electrical system components Systems and components covered in this section are Spark Plugs Battery and Charging System
49. e p O y ale R p m u P A N Y 6 5 2 3 2 1 P d n u o r G o t tiu c ri C tr o h S y ale R p m u P A N Y 6 5 3 3 2 1 P y r e tt a B o t tiu c ri C tr o h S y ale R p m u P A N Y 1 6 n o is si m s n a r T e d o C f o d n E 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 Diagnostic Code Summary cont 5B 33 Section 5B EFI Fuel System 5B Code 21 Source Engine Speed Sensor Explanation ECU receiving inconsistent tooth count signals from speed sensor Expected Engine Response Possible misfire as ECU attempts to resynchronize during which time fuel and spark calculations are not made Possible Causes 1 Engine Speed Sensor Related a Sensor connector or wiring b Sensor loose or incorrect air gap c Flywheel key sheared 2 Speed Sensor Ring Gear Related a Damaged teeth b Varying ga
50. housing retained with two carton staples Commutator Service Clean the commutator with a coarse lint free cloth Do not use emery cloth If the commutator is badly worn or grooved turn it down on a lathe or replace the starter Starter Reassembly 1 Place the thrust washer if so equipped over the drive shaft of the armature Figure 8 39 Style A Commutator End Cap with Brushes Self Tapping Screw Negative Brush Stud Terminal with Positive Brushes Brush Springs Brush Holder Negative Brush Self Tapping Screw Sheet Metal Brush Holder Tool Brush Holder Tool Installed Over Brushes and End Cap 1 2 1 1 3 4 2 1 2 2 Insert the armature into the starter frame Make sure the magnets are closer to the drive shaft end of the armature The magnets will hold the armature inside the frame 3 Install the drive end cap over the drive shaft Make sure the match marks on the end cap and starter frame are aligned See Figure 8 41 Figure 8 41 Starter Assembly Match Marks For Style A Commutator End Caps 4 Install the brush holder tool to keep the brushes in the pockets of the commutator end cap 5 Align the match marks on the commutator end cap and the starter frame Hold the drive end and the commutator end caps firmly to the starter frame Remove the brush holder tool For Style B Commutator End Caps 4 If the brush assembly is no
51. measurements Always use a micrometer Use the following procedure to accurately measure the piston to bore clearance 1 Use a micrometer and measure the diameter of the piston 6 mm 0 24 in above the bottom of the piston skirt and perpendicular to the piston pin See Figure 10 4 6 mm 0 24 in Measure 6 mm above the Bottom of Piston Skirt at Right Angles to Piston Pin 10 5 Section 10 Inspection and Reconditioning 10 Figure 10 5 Checking Cylinder Head Flatness Carefully inspect the valve mechanism parts Inspect the valve springs and related hardware for excessive wear or distortion Check the valves and valve seat area or inserts for evidence of deep pitting cracks or distortion Check clearance of the valve stems in the guides See Figure 10 6 for valve details and specifications Figure 10 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 heads faces and stems with a power wire brush Then carefully inspect each valve for defects such as warped head excessive corrosion or worn stem end Replace valves found to be in bad condition A normal valve and valves in bad condition are shown in the accompanying illustrations EXHAUST VALVE E G F H D D C A B A B A F E G
52. on the solenoid Momentarily connect the other lead to the lower large post terminal See Figure 8 74 When the connection is made the solenoid should energize audible click and the plunger retract Repeat the test several times If the solenoid fails to activate it should be replaced NOTE DO NOT leave the 12 volt test leads connected to the solenoid for any time over what is necessary for performing each of the individual tests Internal damage to the solenoid may otherwise occur Figure 8 74 Testing Pull In Coil Plunger Actuation Test 2 Solenoid Pull In Coil Contact Continuity Test Use an ohmmeter set to the audible or Rx2K scale and connect the two ohmmeter leads to the two large post terminals Perform the preceding test 1 and check for continuity See Figure 8 75 The ohmmeter should indicate continuity if no continuity is indicated the solenoid should be replaced Repeat test several times to confirm condition Figure 8 75 Testing Pull In Coil Solenoid Contact Continuity Test 3 Solenoid Hold In Coil Function Test Connect one 12 volt test lead to the flat spade S start terminal on the solenoid and the other lead to the body or mounting surface of the solenoid Then manually push the plunger In and check if the Hold In coil holds the plunger retracted See Figure 8 76 Do not allow the test leads to remain connected to the solenoid for a prolonged period of time If the plunger fails to sta
53. recheck position of ignition switch and check for shorted kill lead Test Procedure for SMART SPARKTM Ignition Systems The following procedures are provided for troubleshooting ignition problems on SMART SPARKTM equipped engines They will allow you to isolate and pinpoint the failed component s Special Tools Required Hand Tachometer Tester see Section 2 Automotive timing light Multi meter digital Specifications Required Spark plug gap 0 76 mm 0 030 in Ignition module air gap 0 28 0 33 mm 0 011 0 013 in 0 30 mm 0 012 in nominal NOTE Ignition tester see Section 2 must be used to test ignition on these engines Use of any other tester can result in inaccurate findings Battery on unit must be fully charged and properly connected before making any of these tests a battery that is hooked up or charged backward will crank the engine but it won t have spark Be sure drive is in neutral and all external loads are disconnected Test 1 Isolate and verify the trouble is within the engine ignition system 1 Locate the plug connectors where the wiring harnesses from the engine and equipment are joined Separate the connectors and remove the white kill lead from the engine connector Rejoin the connectors and position or insulate the kill lead terminal so it cannot touch ground Try to start the engine to verify whether the reported problem is still present a If the problem
54. s l o o T n o it p ir c s e D o N tr a P e c r u o S h c n e r W p a rt S l e e h w y l F la v o m e r g n ir u d le e h w y lf d lo h o T 9 0 4 2 8 R L K slo o T E S l o o T r e tfi L e v l a V cil u a r d y H sr etfil cil u a r d y h lla ts n i d n a e v o m e r o T S 8 3 1 6 7 5 2 r el h o K r e ts e T m e ts y S n o iti n g I D C t p e c x e s m ets y s lla n o t u p t u o g n its et r o F m ets y s n oiti n g i D C e g r a h c si d e v itic a p a c n o t u p t u o g n its et r o F S 1 0 5 5 4 5 2 r el h o K S 2 0 5 5 4 4 2 r el h o K s e ir e S M amp K h c n e r W t e s ff O st u n g n i n ia te r le rr a b r e d n il y c lla ts n ie r d n a e v o m e r o T 0 1 4 2 8 R L K slo o T E S ti K ts e T e r u s s e r P li O e r u ss e r p lio y fir e v d n a ts et o T S 6 0 1 6 7 5 2 r el h o K t n e r r u c tl o v 0 2 1 r e ts e T r o t a l u g e R r e ifitc e R t n e r r u c tl o v 0 4 2 r e ts e T r o t a l u g e R r e ifitc e R sr o t al u g e r r eifitc e r ts et o t
55. scoring grooving etc no further reconditioning is necessary If the bearing surfaces are worn or damaged the crankcase and or oil pan will need to be replaced Inspect the crankshaft keyways If worn or chipped replacement of the crankshaft will be necessary Inspect the crankpin for score marks or metallic pickup Slight score marks can be cleaned with crocus cloth soaked in oil If wear limits as stated in Specifications and Tolerances are exceeded it will be necessary to either replace the crankshaft or regrind the crankpin to 0 25 mm 0 010 in undersize If reground a 0 25 mm 0 010 in undersize connecting rod big end must then be used to achieve proper running clearance Measure the crankpin for size taper and out of round NOTE If the crankpin is reground visually check to insure that the fillet blends smoothly with the crankpin surface See Figure 10 1 Figure 10 1 Crankpin Fillets Figure 10 2 Removing Crankpin Plug 45 High Point from Fillet Intersections This Fillet Area Must Be Completely Smooth Minimum The Fillet Must Blend Smoothly with the Bearing Journal Surface Flat Washer Self Tapping Screw 12345678 12345678 12345678 12345678 12345678 Plug Crankshaft 10 3 Section 10 Inspection and Reconditioning 10 1 Lower hone into bore and after centering adjust so that the stones are in contact with the cylinder wall Use of a commercial cutting co
56. 0 P r o tiu c ri C n e p O tiu c ri C r o s n e S e r u t a r e p m e T y r e tt a B o t tr o h S Y Y 3 4 A N t e sff O S P T n r a elo tu A g n it elp m o C e r ulia F ti m il elb a w olla m u m in i m w ole b A N Y 4 4 A N t e sff o S P T n r a elo tu A g n it elp m o C e r ulia F ti m il elb a w olla m u m ix a m e v o b a A N Y 1 5 0 6 2 1 P tiu c ri C n e p O 1 r o tc ejnI A N Y 1 5 1 6 2 0 P d n u o r G o t tiu c ri C tr o h S 1 r o tc ejnI A N Y 1 5 2 6 2 0 P y r e tt a B o t tiu c ri C tr o h S 1 r o tc ejnI A N Y 2 5 3 6 2 1 P tiu c ri C n e p O 2 r o tc ejnI A N Y 2 5 4 6 2 0 P d n u o r G o t tiu c ri C tr o h S 2 r o tc ejnI A N Y 2 5 5 6 2 0 P y r e tt a B o t tiu c ri C tr o h S 2 r o tc ejnI A N Y 5 5 1 5 6 1 9 tiu c ri C n e p O p m a L cits o n g a i D A N Y 5 5 2 5 6 1 P d n u o r G o t tiu c ri C tr o h S p m a L cits o n g a i D A N Y 5 5 3 5 6 1 P y r e tt a B o t tiu c ri C tr o h S p m a L cits o n g a i D A N Y 6 5 1 3 2 1 P tiu c ri C n
57. 1 Install the panel to the blower housing 2 Connect the throttle control shaft to the throttle control bracket 3 Connect the choke control cable to the throttle control bracket 4 Connect the Oil Sentry indicator light wires Reconnect Rectifier Regulator 1 Install the rectifier regulator in the blower housing if removed previously then connect the rectifier regulator ground lead with the washer and the silver screw through the eyelet as shown If a grounding bracket is used secure with the mounting screw and washer against the outer side of the rectifier regulator See Figure 11 64 Install Oil Sentry If So Equipped 1 Apply pipe sealant with Teflon Loctite No 59241 or equivalent to the threads of the Oil Sentry switch and install it into the breather cover See Figure 11 63 Torque to 4 5 N m 40 in lb 2 Connect the wire lead green to the Oil Sentry terminal Figure 11 65 Attaching Connector Plug SMART SPARK Module 1 On engines with SMART SPARK reinstall the SAM module to the blower housing or cylinder baffle Do not over tighten the retaining screws 11 19 Section 11 Reassembly 11 Install Valve Covers Three valve cover designs have been used The earliest type used a gasket and RTV sealant between the cover and sealing surface of the cylinder head The second type had a black O Ring installed in a groove on the underside of the cover and may have metal spacers
58. 10 Remove the manifold mounting bolts and separate the throttle body manifold from the engine leaving the TPS fuel rail air baffle injectors and line connections intact Discard the old gaskets 11 Position the manifold assembly over an appropriate container and turn the key switch on to activate the fuel pump and pressurize the system Do not turn switch to start position 12 If either injector exhibits leakage of more than two to four drops per minute from the tip or shows any sign of leakage around the outer shell turn the ignition switch off and replace the injector as follows 13 Depressurize the fuel system following the procedure in the fuel warning on page 5B 2 Remove the two fuel rail mounting screws 14 Clean any dirt accumulation from the sealing mounting area of the faulty injector s and disconnect the electrical connector s 15 Pull the retaining clip off the top of the injector s Disconnect the fuel rail and remove the injector s from the manifold 16 Reverse the appropriate procedures to install the new injector s and reassemble the engine Use new O Rings any time an injector is removed new replacement injectors include new O Rings Lubricate O Rings lightly with oil Torque the fuel rail and blower housing mounting screws to 3 9 N m 35 in lb and the intake manifold and air cleaner mounting screws to 9 9 N m 88 in lb Injector problems due to dirt or clogging are
59. 13 5 Install the oil pan to the crankcase Carefully seat the camshaft and the crankshaft into their mating bearings Rotate the crankshaft slightly to help engage the oil pump and governor gear meshes Apply 1 5 mm 1 16 in bead of sealant RTV must be all around O Ring groove Point B Fill groove between points A and B with RTV Point A Figure 11 18 Oil Pan Fastener Torque Sequence 1 10 8 6 4 2 9 7 5 3 11 7 Section 11 Reassembly 11 Figure 11 23 Clean and Dry Taper of Crankshaft Install Flywheel WARNING Damaging Crankshaft and Flywheel Can Cause Personal Injury Using improper procedures to install the flywheel can crack or damage the crankshaft and or flywheel This not only causes extensive engine damage but can also cause personal 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 flywheel hub are clean dry and completely free of any lubricants The presence of lubricants can cause the flywheel to be over stressed and damaged when the hex flange screw is torqued to specifications Figure 11 22 Installing Backing Plates and Stator Wire Bracket Figure 11 20 Torquing Stator Screws 4 Route the stator leads in the crankcase channel then install the backing plates and stator
60. 300 cca minimum 10 F 23 C or below 400 cca minimum 8 4 Section 8 Electrical System and Components The SMART SPARK ignition system used on some models is an advanced version of the CD ignition system used on other CV engines Its operation can be best understood by first understanding the standard system and how it works Since both systems will continue in use it is advantageous to understand them both The operation of the standard system is explained first then expanded to cover SMART SPARK Electronic CD Ignition Systems Figure 8 3 Electronic CD Ignition System For Customer Connected Tractor Applications Oil Pressure Safety Input Rectifier Regulator B and Carburetor Solenoid Input Ignition Module Input Carburetor Solenoid Oil Pressure Safety Red Green White Ignition Modules Spark Plugs B Violet Red Starter and Carburetor Solenoid Input White Red Red Spark Advance Module Optional Operation of CD Ignition Systems A Capacitive Discharge with Fixed Timing This system Figure 8 3 consists of the following components A magnet assembly which is permanently affixed to the flywheel Two electronic capacitive discharge ignition modules which mount on the engine crankcase Figure 8 4 A kill switch or key switch which grounds the modules to stop the engine Two spark plugs 8 5 8 Section 8 Electrical Sys
61. 32 Figure 11 29 Torquing Supports for Metal Screen Some Models Install Hydraulic Lifters 1 See Servicing Hydraulic Lifters in Section 10 for lifter preparation bleed down procedures 2 Apply camshaft lubricant see Section 2 to the bottom surface of each lifter See Figure 11 30 Lubricate the hydraulic lifters and the lifter bores in the crankcase with engine oil Figure 11 31 Installing Hydraulic Lifters 11 10 Section 11 Reassembly Figure 11 34 Intake Valve Seal Location Assemble Cylinder Heads Prior to installation lubricate all components with engine oil paying particular attention to the lip of the valve stem seal valve stems and valve guides Install the following items in the order listed below using a valve spring compressor See Figures 11 35 and 11 36 Intake and exhaust valves Valve spring caps Valve springs Valve spring retainers Valve spring keepers Figure 11 35 Valve Components Figure 11 33 Installed Breather Reed Valve Stem Seals These engines use valve stem seals on the intake valves and occasionally on the exhaust valves Use a new seal whenever the valve is removed or if the seal is deteriorated or damaged in any way Never reuse an old seal See Figure 11 34 Figure 11 32 Match Numbers on Cylinder Barrel and Head 4 If the breather reeds and stops were removed from the crankcase reinstall them at this time and secure with the hex flan
62. 5 Always use new O Rings and hose clamps when installing a regulator A new replacement regulator will have new O Rings already installed Lubricate the O Rings external regulator with light grease or oil Outlet Port To Fuel Rail Return Port To Tank Inlet Port Pressure Regulating Spring Pressure Regulating Chamber Diaphragm Valve Valve Seat Fuel Chamber a Remove the two screws securing the mounting bracket to the regulator housing Remove the O Ring and pull the regulator out of the housing b Remove the snap ring and remove regulator from base holder Internal In Tank Regulator Remove the three screws securing the retaining ring and regulator in the base holder assembly Grasp and pull the regulator out of the base holder See Figure 5B 28 Figure 5B 27 External Regulators and Base Holders 5B 21 Section 5B EFI Fuel System 5B Fuel Rail 6 Install the new regulator by carefully pushing and rotating it slightly into the base or housing a External Regulators with Square Base Housing Only Install a new O Ring between the regulator and the mounting bracket Set the mounting bracket into position b Secure the regulator in the base with the original retaining ring or screws Be careful not to dent or damage the body of the regulator as operating performance can be affected 7 Reassemble and connect any parts removed in step 3 8 Reconnect the negative battery cable
63. Assembled Into Cast Iron or Steel N m in lb x 0 113 N m ft lb x 1 356 in lb N m x 8 85 ft lb N m x 0 737 Torque Conversions 2 1 Section 2 Tools amp Aids 2 Section 2 Tools amp Aids Certain quality tools are designed to help you perform specific disassembly repair and reassembly procedures By using tools designed for the job you can properly service engines easier faster and safer In addition you ll increase your service capabilities and customer satisfaction by decreasing engine downtime Here is the list of tools and their source Separate Tool Suppliers Kohler Tools Contact your source of supply SE Tools 415 Howard St Lapeer MI 48446 Phone 810 664 2981 Toll Free 800 664 2981 Fax 810 664 8181 Design Technology Inc 768 Burr Oak Drive Westmont IL 60559 Phone 630 920 1300 s l o o T n o it p ir c s e D o N tr a P e c r u o S s e ir e S M amp K l o o T g n i m i T r a e G e c n a l a B e n i g n e g n il b m e ss a n e h w n oitis o p d e m it n i sr a e g e c n ala b d lo h o T S 6 0 5 5 4 5 2 r el h o K 7 5 3 Y y lr e m r o F e t a l P y a l p d n E tf a h s m a C y al p d n e tf a h s m a c g n i k c e h c r o F 5 0 4 2 8 R L K slo o T E S r e ts e T n w o d k a e
64. Camshaft End Play With Shim 0 076 0 127 mm 0 0030 0 0050 in Running Clearance 0 025 0 063 mm 0 0010 0 0025 in Bore I D New 20 000 20 025 mm 0 7874 0 7884 in Max Wear Limit 20 038 mm 0 7889 in Camshaft Bearing Surface O D New 19 962 19 975 mm 0 7859 0 7864 in Max Wear Limit 19 959 mm 0 7858 in Carburetor and Intake Manifold Intake Manifold Mounting Fastener Torque Torque in Two Stages first to 7 4 N m 66 in lb finally to 9 9 N m 88 in lb Carburetor Mounting Nut Torque 6 2 7 3 N m 55 65 in lb Connecting Rod Cap Fastener Torque torque in increments 8 mm straight shank
65. ECU only i Code 51 Injector 1 32 Pin MSE 1 1 Plastic Cased ECU only j Code 52 Injector 2 32 Pin MSE 1 1 Plastic Cased ECU only k Code 55 MIL Light 32 Pin MSE 1 1 Plastic Cased ECU only l Code 56 Pump Relay 32 Pin MSE 1 1 Plastic Cased ECU only 2 MIL circuit grounded between light and ECU 24 Pin MSE 1 0 Plastic Cased ECU Pin circuit 19 32 Pin MSE 1 1 Plastic Cased ECU Pin circuit 29 3 ECU NOTE The MIL in Plastic Cased ECU systems must be a 1 4 watt incandescent lamp Diagnostic Aid 4 SPEED SENSOR MIL does not turn off during cranking Possible causes 1 Speed sensor 2 Speed sensor circuit problem 24 Pin MSE 1 0 Plastic Cased ECU Pin circuits 9 and 10 32 Pin MSE 1 1 Plastic Cased ECU Pin circuits 9 and 10 3 Speed sensor toothed wheel air gap 4 Toothed wheel 5 Flywheel key sheared 6 ECU 5B 41 Section 5B EFI Fuel System 5B Diagnostic Aid 5 FUEL PUMP fuel pump not turning on Possible causes 1 Fuel pump fuse 2 Fuel pump circuit problem 24 Pin MSE 1 0 Plastic Cased ECU Circuits 30 87 and relay 32 Pin MSE 1 1 Plastic Cased ECU Circuits 30 87 and relay 3 Fuel pump Diagnostic Aid 6 RELAY relay not operating Possible causes 1 Safety switches circuit s problem 24 Pin MSE 1 0 Plastic Cased ECU Circuit 3 32 Pin MSE 1 1 Plastic Case
66. Engine starts hard or fails to start when cold 1 Fuel pump not running 2 Faulty spark plugs 3 Old stale fuel 4 Incorrect fuel pressure 5 Speed sensor loose or faulty 6 TPS offset incorrect initialization 7 TPS faulty 8 Engine temp sensor faulty 9 Faulty coils 10 Low system voltage 11 Faulty injectors Engine starts hard or fails to start when hot 1 Faulty spark plugs 2 Fuel pump not running 3 Fuel pressure low 4 Insufficient fuel delivery 5 TPS offset incorrect Initialization 6 Speed sensor loose or faulty 7 TPS faulty 8 Engine temp sensor faulty 9 Faulty injectors Engine stalls or idles roughly cold or warm 1 Faulty spark plugs 2 Insufficient fuel delivery 3 TPS offset incorrect 4 TPS faulty 5 Faulty engine temperature 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 Speed sensor malfunction 7 TPS faulty mounting problem or TPS Initialization Procedure incorrect 8 Bad coil s spark plug s or wires Low Power 1 Faulty malfunctioning ignition system 2 Dirty air filter 3 Insufficient fuel delivery 4 Improper governor adjustment 5 Plugged restricted exhaust 6 One injector not working 7 Basic engine problem exists 8
67. If it didn t move away go to Test 5 b If you were able to check timing on both cylinders the lines you made on the blower housing should be 90 apart If they re not go to Test 4 8 10 Section 8 Electrical System and Components Ignition Module Resistance Table 4 Position a 0 30 mm 0 012 in feeler gauge between the magnet and all three legs of the module The ignition module air gap is critical to proper system performance Do not attempt to set it with a business card or folded microfiche card use the feeler gauge specified 5 Loosen the mounting screws allow the magnet to pull the module down against the feeler gauge and retighten the mounting screws 6 Rotate the flywheel to remove the feeler gauge position the magnet back under the module and recheck that the specified gap minimum of 0 28 mm 0 011 in exists under each leg of the module When you are certain the gap is correct torque the module mounting screws to 4 0 N m 35 in lb On a twin cylinder engine repeat these 6 steps to set the opposite side ignition module 6 Reattach the lead wires to the ignition module s noting if resistance is felt indicating a snug fit between the male and female terminals If any connections do not feel snug disconnect the lead lightly pinch the female terminal with a pliers and recheck the fit 7 When the integrity of all connections has been verified repeat the spark test Test 2 a If
68. Kit 24 757 45 S obtained separately are also being installed 5 15 Section 5 Fuel System and Governor 5 Figure 5 19 Main Jet and Slow Jet Removed 4 Remove the two screws securing the top cover gasket and ground lead fuel solenoid equipped models Discard the gasket and screws only 5 Remove the idle speed and idle fuel adjusting screws and springs from the carburetor Discard the parts 2 Remove the float pin screw and lift out the old float pin and inlet needle See Figure 5 18 Discard all of the parts The seat for the inlet needle is not serviceable and should not be removed Figure 5 18 Removing Float and Inlet Needle 3 Remove and discard the round plug from the bottom of the slow jet tower of the carburetor body Use an appropriate size flat screwdriver and carefully remove the slow and main jets from the carburetor After the main jet has been removed the main nozzle can be taken out through the bottom of the main tower Save the parts for cleaning and reuse See Figure 5 19 NOTE The carburetor is now disassembled for appropriate cleaning and installation of the parts in the overhaul kit Further disassembly is not necessary The throttle shaft assembly fuel inlet seat and bowl chamber baffle are non serviceable items and should not be removed The choke shaft assembly is serviceable however it should not be removed unless a Choke Repair Kit 24 757 36 S will be installed 6 Cl
69. MIL light will not go out when cranking Expected Engine Response None engine will not start or run as the ECU is unable to estimate speed Possible Causes 1 Engine Speed Sensor Related a Sensor connector or wiring b Sensor loose or air gap incorrect 2 Speed Sensor Wheel Related a Damaged teeth b Gap section not registering 3 Engine Wiring Harness Related a Pin circuit wiring or connectors Pin s 9 and or 10 for 24 Pin MSE 1 0 Plastic Cased ECU Pin s 9 and or 10 for 32 Pin MSE 1 1 Plastic Cased ECU 4 ECU Harness Related a ECU to harness connection problem Code 31 Source Fuel Mixture or Oxygen Sensor Explanation System too lean Oxygen sensor not sending expected voltage to ECU Expected Engine Response System operates under open loop control only Until fault is detected and registered by ECU engine will run richif oxygen sensor is shorted to ground or lean if it is shorted to battery voltage After fault is detected performance can vary depending on cause If performance is pretty good the problem is probably with the oxygen sensor wiring or connectors If the engine is still running rich laboring short on power or lean popping or misfiring the fuel mixtureis suspect probably incorrect TPS initialization or low fuel pressure Possible Causes 1 TPS Initialization Incorrect a Lean condition check oxygen sensor signal with VOA and see Oxygen Senso
70. NOTE Do not allow the pulley spring to unwind Enlist the aid of a helper if necessary or use a C clamp to hold the pulley in position 9 Insert the new rope through the rope hole in the starter pulley and the rope guide bushing of the housing See Figure 7 3 Keep Pulley from Rotating Rope Guide Bushing Rope Hole in Pulley Figure 7 3 Installing Rope 10 Tie a slipknot approximately 12 in from the free end of the rope Hold the pulley firmly and allow it to rotate slowly until the slipknot reaches the guide bushing of the housing 11 Slip the handle and rope retainer onto the rope Tie a single knot at the end of the rope Install the rope retainer into the starter handle 12 Untie the slipknot and pull on the handle until the rope is fully extended Slowly retract the rope into the starter When the spring is properly tensioned the rope will retract fully and the handle will stop against the starter housing Pawls Dogs Replacement To replace the pawls follow disassembly steps 1 4 and reassembly steps 3 8 on the following pages A pawl repair kit is available which includes the following components Description Qty Pawl Retainer Center Screw Pawl Dog Spring Brake Spring Starter Pawl Dog Brake Washer Washer 1 1 2 1 2 1 1 Disassembly WARNING Spring Under Tension Do not remove the center screw from starter until the spring tension is released Removing the center screw before relea
71. Note the position routing of the stator lead Figure 9 55 Removing Oil Pan Fasteners Splitting Tabs Figure 9 56 Removing Camshaft Remove Governor Cross Shaft 1 Remove the hitch pin and plain washer or the retainer and nylon washer from the governor cross shaft See Figures 9 57 and 9 58 2 Locate the splitting tabs cast into the perimeter of the oil pan Insert the drive end of a 1 2 breaker bar between the splitting tab and the crankcase and turn it to break the RTV seal See Figure 9 55 Do not pry on the sealing surfaces as this can cause leaks Governor Gear Assembly The governor gear assembly is located inside the oil pan If service is required refer to the service procedures under Governor Gear Assembly in Section 10 Oil Pump Assembly The oil pump is mounted inside the oil pan If service is required refer to the service procedures under Oil Pump Assembly in Section 10 Remove Camshaft 1 Remove the camshaft and shim if used See Figure 9 56 9 16 Section 9 Disassembly Figure 9 60 Removing Connecting Rod End Cap NOTE If a carbon ridge is present at the top of either cylinder bore use a ridge reamer tool to remove it before attempting to remove the piston 2 Carefully remove the connecting rod and piston assembly from the cylinder bore See Figure 9 61 NOTE The cylinders are numbered on the crankcase Use the numbers to mark each end cap connecting rod and piston f
72. Replace fuel filter1 EFI engines Section 5B Daily or Before Starting Engine Maintenance Required Frequency Fill fuel tank Section 5 Check oil level Section 6 Check air cleaner for dirty1 loose or damaged parts Section 4 Check air intake and cooling areas clean as necessary1 Section 4 Service precleaner element1 Section 4 Every 25 Hours Replace air cleaner element1 Section 4 Change oil More frequently under severe conditions Section 6 Remove cooling shrouds and clean cooling areas1 3 Section 4 Check oil cooler fins clean as necessary if equipped Section 6 Check spark plug condition and gap Section 8 Change oil filter Section 6 Check fuel filter carbureted models Section 5 Annually or Every 500 Hours Have bendix starter drive serviced2 Section 8 Have solenoid shift starter disassembled and cleaned2 Section 8 Every 100 Hours Every 200 Hours Every 1500 Hours Have crankshaft splines lubricated2 Section 2 Every 500 Hours Every 250 Hours Replace heavy duty air cleaner element and check inner element1 Section 4 Refer to 1 6 Section 1 Safety and General Information Figure 1 4 Typical Engine Dimensions CV Series with Standard Flat Air Cleaner Dimensions in millimeters Inch equivalents shown in 1 7 Section 1 Safety and General Information 1 Figure 1 5 Typical Engine Dimension
73. Section 5B EFI Fuel System 5B 11 Reconnect the battery cable and all external loads Remove the rubber band from the throttle lever Readjust the idle speed to the equipment manufacturer s specified setting and recheck the high speed no load RPM setting Observe the overall performance TPS Initialization Procedure For 32 Pin MSE 1 1 Plastic Cased ECU Only Auto Learn Initialization 1 Check that the basic engine all sensors fuel fuel pressure and battery are good and functionally within specifications Important 2 Remove disconnect all external loads from the engine belts pumps electric PTO clutch alternator rectifier regulator etc 3 Locate the service connector plug in the wiring harness To initiate the TPS auto learn function connect a jumper wire from the TPS initialization pin 24 violet wire to the battery voltage pin red wire or use the jumper plug with the blue jumper wire If using the PC based diagnostic software see Section 2 go to Special Tests and follow the prompts to complete 4 Start the engine and immediately observe the Malfunction Indicator Light MIL The light should start blinking 4 consecutive times every 2 seconds 5 Remove the jumper wire or plug from the service connector plug 6 Run the engine at full throttle above 3000 RPM to warm up the engine and initiate O2 sensor function in closed loop operation 7 Watch the MIL
74. TPS faulty or mounting exists 9 Throttle plates in throttle body intake manifold not fully opening to WOT stop if so equipped 5B 26 Section 5B EFI Fuel System Electrical System The EFI system is a 12 VDC negative ground system designed to operate down to a minimum of 7 0 volts If system voltage drops below this level the operation of voltage sensitive components such as the ECU fuel pump and injectors will be intermittent or disrupted causing erratic operation or hard starting A fully charged 12 volt battery with a minimum of 350 cold cranking amps is important in maintaining steady and reliable system operation Battery condition and state of charge should always be checked first when troubleshooting an operational problem Keep in mind that EFI related problems are more often caused by the wiring harness or connections than by the EFI components Even small amounts of corrosion or oxidation on the terminals can interfere with the milliamp currents used in system operation Cleaning the connectors and grounds will solve problems in many cases In an emergency situation simply disconnecting and reconnecting the connectors may clean up the contacts enough to restore operation at least temporarily If a fault code indicates a problem with an electrical component disconnect the ECU connector and test for continuity between the component connector terminals and the corresponding terminals in the ECU connector using an ohm
75. a strong steady spark is now present both sides on a twin your problem should be corrected Go to step 4 of Test 5 b If there is still a spark problem perform all of Test 5 Test 5 Test the SAM 1 Trace the red power source lead from the SAM to the harness connection Separate the connector and connect the red lead of a DC voltmeter to the harness terminal Trace the ground lead from the SAM black on singles green on twins to the grounding screw Connect the black voltmeter lead to the eyelet terminal of the ground lead or the ground screw bolt Check the voltage with the key switch in both the START and RUN positions A minimum of 7 25 volts must be present 5 Check and or adjust the ignition module air gap s An air gap of 0 28 0 33 mm 0 011 0 013 in must be maintained under all three legs of the ignition module s Checking adjusting should be performed with the parts at room temperature a If the module was not loosened or replaced check that the specified air gap is present under all three legs If the gap is correct reinstall the second mounting screw removed earlier and recheck gap after tightening b If the gap is incorrect or the module was loosened or replaced adjust the gap as follows 1 Turn the flywheel magnet away from the module position 2 Attach the module to the mounting legs pull it away from the flywheel and snug the screws to hold it temporarily 3 Rotate the f
76. adjusting needle some models is also set at the factory and normally does not need adjustment Depending on model and application engines may also be equipped with a Governed Idle System If equipped with a Governed Idle System refer to Models with Governed Idle System when performing any carburetor adjustment as an additional step to the listed adjustment procedure s is required NOTE Carburetor adjustments should be made only after the engine has warmed up NOTE Certified engines may have a fixed idle or limiter cap on the idle fuel adjusting needle Do not attempt steps 1 and 2 below Proceed directly to step 3 Step 5 can only be performed within the limits allowed by the cap Adjusting Low Idle Fuel and Speed To adjust the carburetor idle fuel and speed see Figure 5 6 and follow these steps 1 With the engine stopped turn the low idle fuel adjusting needle if equipped in clockwise until it bottoms lightly Fuel Shut Off Solenoid 5 9 Section 5 Fuel System and Governor 5 Figure 5 6 Carburetor Adjustments 2 Preliminary Settings Turn the adjusting needle out counterclockwise from lightly bottomed 2 1 4 turns 3 Start the engine and run at half throttle for 5 to 10 minutes to warm up The engine must be warm before making final settings Check that the throttle and choke plates can fully open NOTE The carburetor has a self relieving choke The choke plate and shaft
77. against the idle speed adjusting screw to negate the governor activation See Figure 5 42 Check the speed with a tachometer and adjust it to 1500 RPM 3 Release the governor lever and allow the engine to return to the governed idle speed Check it with a tachometer against the equipment manufacturers recommended idle speed Governed Idle Speed RPM is typically 300 RPM approximate higher than the low idle speed If adjustment is necessary bend the adjusting tab on the speed control assembly to set See Figure 5 41 Lean Rich Adjust to Midpoint Lean Rich Adjust to Midpoint Left Side Right Side Governed Idle Spring Tab Figure 5 42 Holding Throttle Lever Against Idle Stop Screw Two Barrel Carburetor Carburetor Servicing Float Replacement If symptoms described in the carburetor troubleshooting guide indicate float level problems remove the carburetor from the engine to check and or replace the float Use a float kit to replace the float pin float valve clip and screw 1 Perform the removal procedures for the Heavy Duty Air Cleaner and Carburetor outlined in Section 9 Disassembly 2 Clean the exterior surfaces of dirt or foreign material before disassembling the carburetor Remove the four mounting screws and carefully separate the fuel bowl from the carburetor Do not damage the inner or bowl O Ring Transfer any remaining fuel into an approved container Save all parts Fuel can a
78. allowing extra airflow past or restricting movement 4 ECU Related a Circuit providing voltage or ground to TPS damaged b TPS signal input circuit damaged 5 Oxygen Sensor Harness Related a Oxygen sensor bad b Wiring problem to oxygen sensor c Muffler leak causing O2 sensor to falsely indicate a lean condition d Bad ground between ECU and engine Code 51 32 Pin MSE 1 1 Plastic Cased ECU only Source Injector 1 circuit open shorted to ground or shorted to battery Explanation Injector 1 is not functioning because the circuit is open shorted to ground or shorted to battery Expected Engine Response Engine will run very poorly with only one cylinder functioning Possible Causes 1 Injector Related a Injector coil shorted or opened 2 Engine Wiring Harness Related a Broken or shorted wire in harness ECU pin 14 to injector pin 2 ECU pin 28 to fuel pump relay pin 86 Note after key off then key on code 56 would be set also Fuel pump relay pin 87 to injector pin 1 b Open main fuse F1 5B 37 Section 5B EFI Fuel System 5B 3 Fuel Pump Relay Related a Bad fuel pump relay Primary side functional but pin 30 to pin 87 remains open Primary side pin 85 to pin 86 is either open or shorted during engine operation Note after key off then key on code 56 would be set also 4 ECU Related a Circuit controlling injector 1 damaged b Circuit controlling fuel pump r
79. and Reconditioning 10 Excessive Combustion Temperatures The white deposits seen here indicate very high combustion temperatures usually due to a lean fuel mixture Gum Gum deposits usually result from using stale gasoline Gum is a prevalent cause of valve sticking The cure is to ream the valve guides and clean or replace the valves depending on their condition 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 area above the valve guide Worn guides and faulty valve springs may cause this condition Also check for clogged air intake and blocked fins when this condition is noted 10 8 Section 10 Inspection and Reconditioning Valve Guides If a valve guide is worn beyond specifications it will not guide the valve in a straight line This may result in burnt valve faces or seats loss of compression and excessive oil consumption To check valve guide to valve stem clearance thoroughly clean the valve guide and using a split ball gauge measure the inside diameter of the guide Then using an outside micrometer measure the diameter of the valve stem at several points on the stem where it
80. and outlet fittings 2 Remove the hex flange screws securing pump and fuel pump Pulse Line Outlet Line to Carburetor Inlet Line Fuel Pump General These engines are equipped with a pulse type fuel pump The pumping action is created by the oscillation of positive and negative pressures within the crankcase This pressure is transmitted to the pulse pump through a rubber hose connected between the pump and crankcase The pumping action causes the diaphragm on the inside of the pump to pull fuel in on its downward stroke and to push it into the carburetor on its upward stroke Two check valves prevent fuel from going backward through the pump 5 5 Section 5 Fuel System and Governor 5 Figure 5 3 Slow Circuit Fuel Inlet Float Valve Seat Float Valve Main Jet Float Main Emulsion Hole Idle Speed RPM Adjustment Screw Air Fuel Mixture Check Valve Spring Outlet Check Valve Leak Jet Adjustment Screw Diaphragm Spring Pump Diaphragm Inlet Check Valve ACCELERATOR PUMP ASSEMBLY Some Carburetors Fuel Shut Off Solenoid with Main Jet Main Jet Slow Passage Pipe Main Nozzle Throttle Valve Idle Progression Holes Idle Limiter Jet Capped Preset Low Idle Mixture Setting Idle Port Idle Progression Chamber Slow Jet Slow Air Bleed Jet Choke Valve Main Air Bleed Jet Accelerator Pump Nozzle Bowl Vent Slow Circuit See Figure 5 3 A
81. carefully bending the ground electrode See Figure 8 1 Figure 8 1 Servicing Spark Plug 4 Reinstall the spark plug into the cylinder head and torque to 24 4 29 8 N m 18 22 ft lb Inspection Inspect each spark plug as it is removed from the cylinder head The deposits on the tip are an indication of the general condition of the piston rings valves and carburetor Normal and fouled plugs are shown in the following photos Wire Gauge Ground Electrode Spark Plug 0 76 mm 0 030 in Gap 8 2 Section 8 Electrical System and Components Normal A plug taken from an engine operating under normal conditions will have light tan or gray colored deposits If the center electrode is not worn a plug in this condition could be set to the proper gap and reused Wet Fouled A wet plug is caused by excess fuel or oil in the combustion chamber Excess fuel could be caused by a restricted air cleaner a carburetor problem or operating the engine with too much choke Oil in the combustion chamber is usually caused by a restricted air cleaner a breather problem or worn piston rings cylinder walls or valve guides Carbon Fouled Soft sooty black deposits indicate incomplete combustion caused by a restricted air cleaner over rich fuel mixture weak ignition or poor compression Worn On a worn plug the center electrode will be rounded and the gap will be greater than the specified gap Replace a worn spark plug imme
82. choke shaft See Figure 5 63 NOTE Make sure it stays in this location during the following step Figure 5 64 Installing Choke Plate 12 Check for proper operation and free movement of the parts Install the new cap Always use new gaskets when servicing or reinstalling carburetors Repair kits are available which include new gaskets and other components Service repair kits available for Keihin BK two barrel carburetors and affiliated components are Carburetor Overhaul Kit Float Kit Fuel Solenoid Kit Choke Repair Kit Bowl Kit High Altitude Kit 1525 3048 m 5 000 10 000 ft High Altitude Kit Over 3048 m 10 000 ft 11 Place a drop of Loctite on the threads of each new screw Position and install the new choke plate to the flat side of the choke shaft Start the two screws Close the choke and check the plate alignment within the carburetor throat then tighten the screws securely Do not overtighten See Figure 5 64 5 29 Section 5 Fuel System and Governor 5 1 Carburetor Body Subassembly 2 Idle Speed Screw 3 Idle Speed Spring 4 Screw 5 Ground Lead 6 Retaining Washer 7 Slow Jet RH Side 8 Slow Jet LH Side 9 O Ring Slow Jet 2 10 Fuel Bowl 11 O Ring Fuel Bowl Upper 12 O Ring Fuel Bowl Lower 13 Drain Screw 14 Bowl Screw 4 15 Fuel Solenoid 16 Sealing Washer 17 Float 18 Pin 19 Screw 20 Float Clip 21 Float Valve Inlet Needle 22 Main Nozzle Right Side 23 Main
83. connector to the new battery and mount the battery to the case with double backed tape Reinstall the faceplate and secure with the four screws Battery Charging System General Most engines are equipped with a 15 or 20 amp regulated charging system Some have a 25 amp regulated charging system See Figure 8 17 and 8 18 for the 15 20 25 amp charging system diagram Some engines utilize a 3 amp unregulated system with optional 70 watt lighting circuit Refer to Figure 8 23 NOTE Observe the following guidelines to avoid damage to the electrical system and components Make sure the battery polarity is correct A negative ground system is used Disconnect the rectifier regulator plug and or the wiring harness plug before doing any electric welding on the equipment powered by the engine Also disconnect all other electrical accessories in common ground with the engine Prevent the stator AC leads from touching or shorting while the engine is running This could damage the stator Figure 8 15 Select Test Number 4 If you get a sign instead of the numerical sequence and or an F at the end of the test cycle recheck all of the connections check the condition of the tester battery and repeat the test If you get the or F sign again in the retest replace the SAM IMPORTANT Allow 15 20 seconds for the tester to clear and reset itself between tests or if the test is interrupted
84. d e s U S 0 2 1 6 7 5 2 r el h o K S 1 4 1 6 7 5 2 r el h o K el b alia v A st n e n o p m o C la u d iv i d n I ss e n r a H ts e T r o t al u g e R O R P S C e d oi D h ti w ss e n r a H ts e T r o t al u g e R laic e p S c n I y g olo n h c e T n g is e D 1 3 0 I T D 3 3 0 I T D r e ts e T M A S e l u d o M e c n a v d A k r a p S K R A P S T R A M S h ti w s e n i g n e n o M A S D d n a M A S A M A S e h t ts et o T S 0 4 1 6 7 5 2 r el h o K tfi h S d i o n e l o S l o o T g n i d l o H h s u r B r e tr a t S g n iciv r e s g n ir u d s e h s u r b d lo h o T 6 1 4 2 8 R L K slo o T E S e v ir D a itr e n I l o o T g n i R g n i n i a t e R r e tr a t S sr etr a ts O C S A F g n i d u lc x e s g n ir g n i n ia te r e v ir d lla ts n ie r d n a e v o m e r o T S 8 1 1 6 7 5 2 r el h o K s r e tr a t S ll A ti K g n ici v r e S r e tr a t S s e h s u r b d n a s g n ir g n i n ia te r e v ir d lla ts n ie r d n a e v o m e r o T 1 1 4 2 8 R L K slo o
85. front and the rear stop collars together over the retainer Using two pairs of pliers apply even force to the two collars until they snap over the retainer and nest into one another 4 Reassemble the remaining components of the starter in reverse order from disassembly Delco Remy Starters Figure 8 44 Completed Delco Remy Starter Starter Disassembly 1 Remove the hex nut and disconnect the positive brush lead bracket from the solenoid terminal 2 Remove the three screws securing the solenoid to the starter See Figure 8 45 8 31 8 Section 8 Electrical System and Components Figure 8 45 Removing Solenoid Screws 3 If the solenoid was mounted with Phillips head screws separate the solenoid and plunger spring from the drive end cap If the solenoid was mounted with external Torx head screws the plunger is part of the solenoid unhook the plunger pin from the drive lever Remove the gasket from the recess in the housing See Figures 8 46 and 8 47 NOTE Test procedure for checking starter solenoid on pages 8 39 and 8 40 Figure 8 47 Removing Plunger 4 Remove the two thru larger bolts See Figure 8 48 Figure 8 46 Solenoid Removed from Starter Phillips Head Screws Torx Head Screws 8 32 Section 8 Electrical System and Components Figure 8 48 Removing Thru Bolts 5 Remove the commutator end plate assembly containing the brush holder brushes springs and locking caps Remove t
86. grass screen cooling fan fins and other external surfaces of the engine are kept clean at all times Every 100 hours of operation more often under extremely dusty or dirty conditions remove the blower housing and other cooling shrouds Clean the cooling fins and external surfaces as necessary Make sure the cooling shrouds are reinstalled Cleanout kits Kohler Part No 25 755 20 S black or 25 755 21 S gold are recommended to aid inspection and cleanout of the cooling fins See Figure 4 11 NOTE Operating the engine with a blocked grass screen dirty or plugged cooling fins and or cooling shrouds removed will cause engine damage due to overheating Figure 4 11 Cleanout Kit Installed on Blower Housing 5 1 Section 5 Fuel System and Governor 5 Section 5 Fuel System and Governor Description The Command vertical twins use two different types of fuel systems carbureted or electronic fuel injection EFI This section covers the standard carbureted fuel systems The EFI fuel systems are covered in subsection 5B The governor systems used are covered at the end of this section WARNING Explosive Fuel Gasoline is extremely flammable and its vapors can explode if ignited Store gasoline only in approved containers in well ventilated unoccupied buildings away from sparks or flames Do not fill the fuel tank while the engine is hot or running since spilled fuel could ignite if it comes in contact with
87. in the bolt holes The newest design uses a yellow or brown O Ring and the bolt hole spacers are molded in place The tightening torque differs between gasket and O Ring style covers Kits are available for converting to the latest O Ring type covers Differences are pointed out in the following installation steps NOTE Do not scrape old RTV sealant if used off the sealing surface of the cylinder head as this could cause damage and result in leaks The use of gasket remover solvent paint remover is recommended 1 If using the gasket or sealant type cover prepare the sealing surfaces of the cylinder head and cover as directed in Service Bulletin 252 Refer to Section 2 for approved sealants Always use fresh sealant using outdated sealant could result in leakage With O Ring type covers make sure the sealing surfaces are clean 2 Make sure there are no nicks or burrs on the sealing surfaces 3 For covers requiring RTV sealant apply a 1 5 mm 1 16 in bead to the sealing surface of both cylinder heads install a new cover gasket on each then apply a second bead of sealant on the top surface of the gaskets For O Ring type covers install a new O Ring in the groove of each cover Do not use gaskets or RTV sealant 4 Position the covers on the cylinder heads Locate the cover with the oil separator hole on the 1 cylinder If loose spacers were used insert a spacer in each of the screw holes Install the four hex f
88. moves in the valve guide Use the largest stem diameter to calculate the clearance by subtracting the stem diameter from the guide diameter If the intake clearance exceeds 0 038 0 076 mm 0 0015 0 0030p in or the exhaust clearance exceeds 0 050 0 088 mm 0 0020 0 0035 in determine whether the valve stem or guide is responsible for the excessive clearance The maximum I D wear on the intake valve guide is 7 134 mm 0 2809 in while 7 159 mm 0 2819 in is the maximum allowed on the exhaust guide The guides are not removable but can be reamed 0 25 mm 0 010 in oversize Valves with 0 25 mm oversize stems must then be used If the guides are within limits but the valve stems are worn beyond limits install new valves Valve Seat Inserts Hardened steel alloy intake and exhaust valve seat inserts are press fitted into the cylinder head The inserts are not replaceable but can be reconditioned if not too badly pitted or distorted If cracked or badly warped the cylinder head should be replaced Recondition the valve seat inserts following the instructions provided with the valve seat cutter being used A typical cutter is shown in Figure 10 7 The final cut should be made with an 89 cutter as specified for the valve seat angle in Figure 10 6 Cutting the proper 45 valve face angle as specified in Figure 10 6 and the proper valve seat angle 44 5 half of the full 89 angle will achieve the desired 0 5 1 0 full cu
89. often more severe than detonation damage Preignition is caused by a hot spot in the combustion chamber from sources such as glowing carbon deposits blocked cooling fins an improperly seated valve or wrong spark plug s See Figure 10 8 for some common types of piston and ring damage Figure 10 8 Common Types of Piston Damage Overheated or Deteriorated Oil Scored Piston and Rings Abrasive Scratched Rings Stuck Broken Rings 10 10 Section 10 Inspection and Reconditioning Figure 10 10 Measuring Piston Ring Side Clearance Install New Piston Rings To install new piston rings proceed as follows NOTE Rings must be installed correctly Ring installation instructions are usually included with new ring sets Follow instructions carefully Use a piston ring expander to install rings See Figure 10 11 Install the bottom oil control ring first and the top compression ring last Refer to Figure 10 12 Replacement pistons are available in STD bore size and 0 25 mm 0 010 in and 0 50 mm 0 020 in oversize Replacement pistons include new piston ring sets and new piston pins Replacement ring sets are also available separately for STD 0 25 mm 0 010 in and 0 50 mm 0 020 in oversize pistons Always use new piston rings when installing pistons Never use old rings Some important points to remember when servicing piston rings 1 The cylinder bore must be deglazed before service ring sets are used 2
90. 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 diameter threads 1 2 11 12 Section 11 Reassembly Figure 11 41 Install Push Rods in Their Original Position 2 Apply grease to the contact surfaces of the rocker arms and rocker arm pivots Install the rocker arms and rocker arm pivots on one cylinder head and start the two hex flange screws 3 Torque the hex flange screws to 11 3 N m 100 in lb See Figure 11 42 Figure 11 40 Torquing the Cylinder Head Mounting Nuts Stud Design Install Push Rods and Rocker Arms NOTE Push rods should always be installed in the same position as before disassembly 1 Note the mark or tag identifying the push rod as either intake or exhaust and cylinder 1 or 2 Dip the ends of the push rods in engine oil and install making sure that each push rod ball seats in its hydraulic lifter socket See Figure 11 41 b Thread the opposite end of the stud with the preapplied locking compound into the crankcase until the specified height from the crankcase surface is achieved See Figure 11 39 When threading in the studs use a steady tightening motion without interruption until the proper height is obtained Otherwise the frictional heat from the engaging threads may cause the locking compound to set
91. or the dykem stripe if contained is to the left of the end gap Connecting Rods Offset stepped cap connecting rods are used in all these engines Inspection and Service Check the bearing area big end for excessive wear score marks running and side clearances refer to Section 1 Specifications Tolerances and Special Torque Values Replace the rod and cap if scored or excessively worn 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 rods have an identification marking on the lower end of the rod shank Always refer to the appropriate parts information to ensure that correct replacements are used Hydraulic Lifters Inspection Check the base surface of the hydraulic lifters for wear or damage If the lifters need to be replaced apply a liberal coating of Kohler lubricant see Section 2 to the base of each new lifter before it is installed Bleeding the Lifters To prevent a possible bent push rod or broken rocker arm it is important to bleed any excess oil out of the lifters before they are installed 1 Cut a 50 75 mm 2 3 in piece from the end of an old push rod and chuck it in a drill press 2 Lay a rag or shop towel on the table of the drill press and place the lifter open end up on the towel 3 Lower the chucked push rod until it contacts the plunger in the lifter Slowly pump the plun
92. plug boot terminal and the red primary terminal Secondary resistance should be 13 000 17 500 4 If the secondary resistance is not within the specified range unscrew the spark plug lead nut from the coil secondary tower and remove the plug lead Repeat step b 3 testing from the secondary tower terminal to the red primary terminal If resistance is now correct the coil is good but the spark plug lead is faulty replace the lead If step b 2 resistance was incorrect and or the secondary resistance is still incorrect the coil is faulty and needs to be replaced 5B 18 Section 5B EFI Fuel System Spark Plugs EFI engines are equipped with Champion RC12YC Kohler Part No 12 132 02 S resistor spark plugs Equivalent alternate brand plugs can also be used but must be resistor plugs or permanent damage to the ECU will occur in addition to affecting operation Proper spark plug gap is 0 76 mm 0 030 in Wiring Harness The wiring harness used in the EFI system connects the electrical components providing current and ground paths for the system to operate All input and output signaling occurs through a special all weather connector that attaches and locks to the ECU see Figures 5B 21 and 5B 22 The condition of the wiring connectors and terminal connections is essential to system function and performance Corrosion moisture and poor connections are more likely the cause of operating problems and sys
93. pulley housing so the pulley is away from your face and away from others in the area 7 Rotate the pulley slightly from side to side and carefully separate the pulley from the housing See Figure 7 6 If the pulley and the housing do not separate easily the spring could be engaged in the starter housing or there is still tension on the spring Return the pulley to the housing and repeat step 5 before separating the pulley and housing Brake Spring and Brake Washer Pawls Pawl Spring Figure 7 7 Position of Spring and Keeper in Pulley Inspection and Service 1 Carefully inspect the rope pawls housing center screw and other components for wear or damage 2 Replace all worn or damaged components Use only genuine Kohler replacement parts as specified in the Parts Manual All components shown in Figure 7 1 are available as service parts Do not use nonstandard parts Rope Hole in Pulley Outer Spring Hook Spring amp Keeper 7 4 Section 7 Retractable Starter Figure 7 8 Installing Pulley and Spring into Housing 3 Install the pawl springs and pawls into the starter pulley See Figure 7 9 Pulley amp Spring Housing Pawl Pawl Spring 3 Do not attempt to rewind a spring that has come out of the keeper Order and install a new spring and keeper assembly 4 Clean all old grease and dirt from the starter components Generously lubricate the spring and center shaft with any commercially
94. remove the cover gasket 7 Remove the idle fuel adjusting needle and spring if it does not have a limiter Remove the idle speed screw and spring Except for the slow jet nozzle main jet and emulsion tubes which are considered non serviceable the carburetor is now completely disassembled and ready for thorough inspection and cleaning 5 12 Section 5 Fuel System and Governor Figure 5 10 Typical Carburetor Exploded View Inspection Repair To clean vent ports seats etc use a good commercially available carburetor solvent such as Gumout and clean dry compressed air to blow out internal channels and ports Use a suitable shop rag to prevent debris from hitting someone Carefully inspect all components and replace those that are worn or damaged Inspect the carburetor body for cracks holes and other wear or damage Inspect the float for cracks holes and missing or damaged float tabs Check the float hinge and shaft for wear or damage Inspect the fuel inlet needle and seat for wear or damage Inspect the tip of the low idle fuel adjusting needle if equipped for wear or grooves The choke plate is spring loaded Check to make sure it moves freely 1 Carburetor Body 2 Idle Fuel Adjusting Screw 3 Idle Fuel Adjusting Spring 4 Passage Cover 5 Cover Gasket 6 Cover Retaining Screw 7 Main Jet 8 Ground Lead Solenoid only 9 Fuel Bowl Gasket 10 Float Kit
95. ring snap into the groove Disassemble and remove the tool 4 Squeeze the retaining ring with a pliers to compress it into the groove 5 Assemble the inner halves with the larger cavity around the spring retainer see Figure 8 38 Slide the collar over them and thread the center screw in until resistance is felt Figure 8 38 Assembling Larger Inner Half Around Spring Retainer 6 Hold the base of the tool with a 1 1 8 wrench and turn the center screw clockwise with a 1 2 or 13 mm wrench to draw the spring retainer up around the retaining ring Stop turning when resistance increases Disassemble and remove the tool 7 Reinstall the dust cover Starter Disassembly 1 Remove the drive components following the instructions for servicing the drive 2 Locate the small raised line on the edge of the drive end cap On starters with Style A commutator end caps it will be aligned with a pre marked line on the starter frame The frame is not pre marked on starters with Style B end caps Place a piece of masking tape on the frame and mark a line on the tape in line with the raised line on the end cap See Figure 8 41 3 Remove the thru bolts 4 Remove the commutator end cap with brushes and brush springs Style A Style B end caps remove as a separate piece with the brushes and carrier remaining in the frame 5 Remove the drive end cap 6 Remove the armature and thru
96. speed When load is applied and the engine speed and governor gear speed decreases the governor spring tension moves the governor lever to open the throttle plate wider This allows more fuel into the engine increasing engine speed As speed reaches the governed setting the governor spring tension and the force applied by the regulating pin will again offset each other to hold a steady engine speed Hex Nut Cross Shaft Governor Spring Governor Arm 5 31 Section 5 Fuel System and Governor 5 Sensitivity Adjustment Governor sensitivity is adjusted by repositioning the governor spring in the holes of the governor lever If speed surging occurs with a change in engine load the governor is set too sensitive If a big drop in speed occurs when normal load is applied the governor should be set for greater sensitivity See Figure 5 66 and adjust as follows 1 To increase the sensitivity move the spring closer to the governor lever pivot point 2 To decrease the sensitivity move the spring away from the governor lever pivot point High Speed RPM Adjustment Refer to Figures 5 67 5 68 or 5 69 1 With the engine running move the throttle control to fast Use a tachometer to check the RPM speed 2 Loosen the lock nut on the high speed adjusting screw Turn the screw counterclockwise to decrease or clockwise to increase RPM speed Check RPM with a tachometer 3 When the desired RPM speed is
97. stop screw turn the ignition switch to the on position do not start the engine and observe the Malfunction Indicator Light MIL a The light should blink on off quickly for approximately 3 seconds and then go off and stay off indicating the initialization procedure has been successful b If the light stays on or blinking ceases prematurely the procedure was unsuccessful and must be repeated Possible causes for unsuccessful learning may be 1 Movement occurred in either the TPS or throttle shaft during procedure 2 Crankshaft movement wasdetected by the speed sensor during procedure 3 Throttle plate position was out of learnable range recheck the 1500 RPM idle speed adjustment or 4 Problem with ECU or TPS 9 When the initialization procedure has been successfully completed turn off the key switch remove the jumper wire or connector and remove the rubber band from the throttle lever 10 Disconnect the ECU connector plug or the negative battery cable temporarily one minute minimum to clear all learned adjustments 24 Pin MSE 1 0 Plastic Cased ECU Pin circuits 8 and 4 32 Pin MSE 1 1 Plastic Cased ECU Pin circuits 8 and 4 a Repair or replace as required b Turn the idle speed screw back in to its original setting c Reconnect connector plugs start engine and retest system operation 7 Remove the two mounting screws from the TPS Save the screws for reuse Re
98. sure the oil drain plugs oil sentry pressure switch and a new oil filter are installed 3 Fill the crankcase with the correct amount weight and type of oil Refer to oil recommendations and procedures in the Safety and General Information and Lubrication System sections 4 Adjust the carburetor idle fuel needle or idle speed adjusting screw as necessary Refer to Section 5 Fuel System and Governor Testing the Engine It is recommended that the engine be operated on a test stand or bench prior to installation in the piece of equipment 1 Set the engine up on a test stand Install an oil pressure gauge Start the engine and check to be certain that oil pressure 20 psi or more is present Run the engine at idle for 2 3 minutes then 5 6 minutes more between idle and midrange Adjust the carburetor mixture settings as necessary as available 2 Adjust the idle speed screw and high speed stop as necessary Make sure the maximum engine speed does not exceed 3750 RPM no load NOTE Make sure that both oil drain plugs are installed and torqued to the above specifications to prevent oil leakage 5 Add oil to bring the level up to the Full mark and reinstall the dipstick Connect Spark Plug Leads 1 Connect the leads to the spark plugs See Figure 11 93 Drain Plug Figure 11 93 Connect Spark Plug Leads LITHO IN U S A FORM NO TP 2450 C ISSUED 3 94 REVIS
99. the spark advance module Figure 8 7 The pulse generated by the input coil of the ignition module L1 Figure 8 5 is fed to the input of the conditioning circuit The conditioning circuit shapes this pulse putting it in a useable form for the additional circuits This pulse starts the charge pump which charges a capacitor in a linear fashion that can be directly related to the engine speed At the same time the pulse resets the delay circuit for length of the pulse width The comparator is off during this period and no output is generated As soon as the original pulse drops back to zero the capacitor in the delay circuit begins to charge When the charge on the delay capacitor exceeds the charge on the charge pump capacitor the comparator changes state activating the pulse generator This pulse turns ON the CD ignition module semiconductor Energy is then transferred to the secondary of the output transformer T1 Figure 8 5 The high voltage pulse generated here is delivered to the spark plug causing arcing of the spark gap and igniting the fuel air mixture in the combustion chamber As the trigger pulse is generated all associated circuits are reset their capacitors discharged The longer it takes the delay circuit to surpass the charge pump capacitor voltage the later the trigger pulse will occur retarding the timing accordingly Troubleshooting CD Ignition Systems The CD ignition systems are designed to be trouble
100. 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 11 85 and 11 86 Lower Screws Figure 11 86 Tightening Lower Base Bracket Screws Some Models 4 Install the air cleaner components as described in Section 4 Heavy Duty Air Cleaners 1 Install a new air cleaner base gasket 2 Attach the main support bracket to the four inboard valve cover screw locations Make sure each of the mounting holes has a loose or integral spacer Leave screws slightly loose 3 Install the elbow adapter onto the mounting studs Secure with and torque the hex flange nuts to 6 2 7 3 N m 55 65 in lb See Figure 11 87 Figure 11 87 Torquing Hex Nuts Two Barrel Model Shown 4 Install and tighten the two mounting screws securing the air cleaner mounting bracket and the control panel to the blower housing See Figure 11 88 Mounting Nuts 11 28 Section 11 Reassembly Figure 11 89 Securing Air Cleaner Mounting Bracket 6 Two Barrel Carburetor Models Only Attach the choke return spring to the bottom of the main control bracket See Figure 11 90 Figure 11 90 Attaching Choke Return Spring Two Barrel Carburetors Choke Return Spring Install Muffler 1 Install the port liners if equipped Install the muffler and attaching hardware to the muffler bracket Torque screws to 9 9 N m 88 in lb 2 Insta
101. the coils with the ignition on as they may overheat or spark Testing 1 Disconnect the main harness connector from the ECU 24 Pin MSE 1 0 Plastic Cased ECU Locate pins 22 and 23 in the 24 pin connector See page 5B 26 32 Pin MSE 1 1 Plastic Cased ECU Locate pins 30 and 31 in the 32 pin connector See page 5B 29 2 Disconnect connector from relay and locate terminal 87 in connector 3 Using an ohmmeter set on the Rx1 scale check the resistance in circuits as follows 24 Pin MSE 1 0 Plastic Cased ECU Check between terminal 87 and pin 22 for coil 1 Repeat the test between terminal 87 and pin 23 for coil 2 32 Pin MSE 1 1 Plastic Cased ECU Check between terminal 87 and pin 30 for coil 1 Repeat the test between terminal 87 and pin 31 for coil 2 A reading of 1 8 4 0 in each test indicates that the wiring and coil primary circuits are OK a If reading s are not within specified range check and clean connections and retest b If reading s are still not within the specified range test the coils separately from main harness as follows 1 Disconnect the red and black primary leads from the coil terminals 2 Connect an ohmmeter set on the Rx1 scale to the primary terminals Primary resistance should be 1 8 2 5 3 Disconnect the secondary lead from the spark plug Connect an ohmmeter set on the Rx10K scale between the spark
102. the spring 180 until hooked as shown in Figure 5 69 3 Hook the short end of the spring into the appropriate hole in the governor lever Refer to the appropriate chart in Section 11 Reassembly of this manual for the correct hole to use for the speed involved Choke Cable Choke Lever See Detail at Left Clamp Throttle Cable Spring Bushing Linkage Throttle Lever Washer Throttle Shaft Bracket Spacer Deflector If So Equipped Place Between Valley Baffle and Throttle Shaft Bracket Bushing Blower Housing Washer Lever Spring Screw and Nut Control Lever Control Bracket Spring Clip Locker Nut Fuel Line Clamp Fuel Pump Fastener Lock Nut Fastener Choke Lever Spacer Spring Washer Bushing Screw Lock Nut Washer Linkage 5 33 Section 5 Fuel System and Governor 5 Washer Lock Nut Choke Linkage Bushing Spacer Spring Washer Choke Cable Clamp and Screw Control Bracket Screw Spring Washer Hex Nut Screw Throttle Control Lever Lock Nut Throttle Cable Bushing Throttle Linkage Fuel Pump Clamp Fuel Throttle Shaft Bushing Throttle Shaft Bracket Deflector If So Equipped Throttle Lever Lock Nut Spacer Washer Governor Spring Governor Lever Linkage Spring Screw Figure 5 69 Governor Controls Assembly CV750 5B 1 Section 5B EFI Fuel System 5B Section 5B Electron
103. until the piston of cylinder being tested is at top dead center of the compression stroke Hold the engine in this position while testing The holding tool supplied with the tester can be used if the PTO end of the crankshaft is accessible Lock the holding tool onto the crankshaft Install a 3 8 breaker bar into the hole slot of the holding tool so it is perpendicular to both the holding tool and crankshaft PTO If the flywheel end is more accessible use a breaker bar and socket on the flywheel nut screw to hold it in position An assistant may be needed to hold the breaker bar during testing If the engine is mounted in a piece of equipment it may be possible to hold it by clamping or wedging a driven component Just be certain that the engine cannot rotate off of TDC in either direction 4 Install the adapter into the spark plug hole but do not attach it to the tester at this time 5 Connect an air source of at least 50 psi to the tester 6 Turn the regulator knob in the increase clockwise direction until the gauge needle is in the yellow set area at the low end of the scale 7 Connect the tester quick disconnect to the adapter hose while firmly holding the engine at TDC Note the gauge reading and listen for escaping air at the carburetor intake exhaust outlet and crankcase breather 8 Check the test results against the following table 3 5 Section 3 Troubleshooting 3 Air escaping from cr
104. up prematurely The studs closest to the lifters must have an exposed height of 75 mm 2 15 16 in The studs furthest from the lifters must have an exposed height of 68 mm 2 3 4 in c Remove the nuts and repeat the procedure as required Figure 11 39 Installing New Mounting Studs to Specified Height 4 Check that the dowel pins are in place and install a new cylinder head gasket printing up 5 Install the cylinder head Match the numbers on the cylinder heads and the crankcase See Figure 11 32 Make sure the head 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 then finally to 33 9 N m 300 in lb following the sequence in Figure 11 38 11 13 Section 11 Reassembly 11 Figure 11 43 Using Spanner Wrench to Lift Rocker Arm Over Push Rod 5 Repeat the above steps for the remaining cylinder Do not interchange parts from the cylinder heads 6 Rotate the crankshaft to check for free operation of the valve train Check the clearance between the valve spring coils at full lift Minimum allowable clearance is 0 25 mm 0 010 in Check Assembly Important Rotate the crankshaft a minimum of two revolutions to check longblock assembly and overall proper operation Install Spark Plugs 1 Use new Cha
105. with engine running at 3000 RPM no load Battery must be good and fully charged Problem No Charge to Battery No Lights Test 1 With engine running at 3000 RPM measure voltage across battery terminals using a DC voltmeter 2 Disconnect the charging lead from battery With engine running at 3000 RPM measure voltage from charging lead to ground using a DC voltmeter 3 With charging lead disconnected from battery and engine stopped measure resistance from charging lead to ground using an ohmmeter Note reading Reverse the leads and measure resistance again In one direction the resistance should be infinity ohms open circuit With the leads reversed some resistance should be measured about midscale on Rx1 range 4 Cut the sleeving on the charging lead to expose the diode connections Measure the resistance from the stator side of diode to ground using an ohmmeter 1 Make sure lights are not burned out 2 Disconnect the lighting lead from the wiring harness With engine running at 3000 RPM measure voltage from lighting lead to ground using an AC voltmeter 3 With engine stopped measure the resistance of stator from lighting lead to ground using an ohmmeter Conclusion 1 If voltage is more than 12 5 volts charging system is OK If voltage is 12 5 volts or less the stator or diode are probably faulty Test the stator and diode Tests 2 3 and 4 2 If voltage is 2
106. 0 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 Function Permanent Battery Voltage Switched Battery Voltage TPS Set Auto Learn Initialization Terminal Throttle Position Sensor TPS and Temperature Sensor Ground Not Used Oil Temperature Sensor Input Not Used Throttle Position Sensor TPS Input Speed Sensor Input Speed Sensor Ground Not Used Not Used Not Used Injector 1 Output Injector 2 Output Not Used Diagnostic Line Throttle Position Sensor Supply Voltage Battery Ground Oxygen Sensor Input Battery Ground secondary Not Used Not Used Not Used Safety Switch Input Not Used Not Used Main Relay Output Malfunction Indicator Light MIL Ignition Coil 1 Output Ignition Coil 2 Output Not Used 1 2 3 4 5 6 7 8 9 10 11 12 17 18 19 20 21 22 23 24 25 26 27 28 13 14 29 30 15 16 31 32 5B 30 Section 5B EFI Fuel System Fuel System WARNING Fuel System Under Pressure The fuel system operates under high pressure System pressure must be relieved through the test valve in the fuel rail prior to servicing or removal of any fuel system components Do not smoke or work near heaters or other fire hazards Have a fire extinguisher handy and work only in a well ventilated area The function of the fuel system is to provide sufficient delivery of fuel at the system operating pressure of
107. 1 Figure 5 31 Removing Retaining Ring 4 Clean the accelerator pump housing and cover as required 5 Install the new check valve into the fuel delivery chamber Secure with the new retaining ring See Figure 5 32 Figure 5 32 Check Valve and Retaining Ring Installed 6 Notice the small alignment tab and the small bead on one side of the outer diameter of the new diaphragm Install the diaphragm into the housing so the alignment tab is in the small notch the bead is down in the recessed channel and the donut around the metal center plate should be out facing you See Figure 5 33 Figure 5 33 Diaphragm Installed 7 Install the new diaphragm spring and reinstall the accelerator pump cover Secure with the three new screws Torque the screws to 2 0 0 6 N m 18 2 5 2 in lb See Figure 5 34 5 19 Section 5 Fuel System and Governor 5 Figure 5 34 Installing Accelerator Pump Housing Screws and Hose 8 Install the new clips onto each end of the new vacuum hose and connect the hose onto the fittings See Figure 5 34 Discard all the old parts Choke Repair 1 Remove the carburetor from the engine Discard the old mounting gaskets for the air cleaner and carburetor 2 Clean the areas around the choke shaft and the self relieving choke mechanism thoroughly 3 Remove and discard the plastic cap from the end of the choke lever shaft assembly 4 Note the position of the spring legs
108. 11 Fuel Bowl 12 Bowl Retaining Screw Gasket 13 Bowl Retaining Screw 14 Shut off Solenoid Assembly 15 Throttle Shaft Lever 16 Throttle Plate 17 Choke Shaft 18 Choke Plate 19 Air Filter 20 Collar 21 Spring 22 Ring 23 Choke Lever 24 Idle Speed Screw 25 Idle Speed Spring 26 Setscrews Plates 4 Included in Carburetor Repair Kit or 14 13 12 11 10 9 16 8 7 3 25 24 17 23 21 19 20 22 15 1 18 2 5 6 26 4 5 13 Section 5 Fuel System and Governor 5 Always use new gaskets when servicing or reinstalling carburetors Repair kits are available which include new gaskets and other components Service repair kits available for Nikki carburetors and affiliated components are Carburetor Repair Kit Float Kit High Altitude Kit 1525 3048 m 5 000 10 000 ft High Altitude Kit Over 3048 m 10 000 ft Solenoid Assembly Kit Reassembly Procedure Reassembly is essentially the reverse of the disassembly procedure Use new gaskets springs and adjusting screws as provided in the carburetor repair kit Also use new carburetor and intake manifold gaskets Set the idle speed RPM adjusting screw if equipped 2 1 4 turns open for initial adjustment and make final adjustments as described earlier Keihin Carburetors CV17 740 Float Replacement 1 Clean the exterior surfaces of dirt or foreign material before disassembling the carburetor Uns
109. 3 2 6 in lb 17 Place the longer new spring onto the idle fuel adjusting screw and install it into the carburetor As an initial adjustment set to 1 turn out from lightly seated See Figure 5 28 Figure 5 28 Installing Idle Fuel Adjusting Screw and Spring 18 Place the shorter new spring onto the idle speed adjusting screw and install it into the carburetor Thread in until 3 or 4 threads are exposed as an initial adjustment See Figure 5 29 Figure 5 29 Installing Idle Speed Adjusting Screw and Spring Accelerator Pump Rebuild NOTE Access to the accelerator pump can be limited due to specific engine options or the application Although installation of the kit is possible with the carburetor intact removal is normally necessary and recommended These instructions cover installation of the kit components only If needed instructions for removal and reinstallation of the carburetor can be found in Sections 9 and 11 respectively 1 Remove the vacuum hose from the accelerator pump cover and the carburetor flange fitting 5 18 Section 5 Fuel System and Governor 2 Remove the three screws securing the cover to the accelerator pump housing Remove the cover spring and diaphragm See Figure 5 30 Figure 5 30 Accelerator Pump Cover and Diaphragm Removed 3 Remove the retaining ring over the rubber check valve using a snap ring pliers Remove the check valve from the fuel delivery chamber See Figure 5 3
110. 3 in 4 After resizing check the bore for roundness taper and size Use an inside micrometer telescoping gauge or bore gauge to take measurements The measurements should be taken at three locations in the cylinder at the top middle and bottom Two measurements should be taken perpendicular to each other at each of the three locations Clean Cylinder Bore After Honing Proper cleaning of the cylinder walls following boring and or honing is very critical to a successful overhaul Machining grit left in the cylinder bore can destroy an engine in less than one hour of operation after a rebuild The final cleaning operation should always be a thorough scrubbing with a brush and hot soapy water Use a strong detergent that is capable of breaking down the machining oil while maintaining a good level of suds If the suds break down during cleaning discard the dirty water and start again with more hot water and detergent Following the scrubbing rinse the cylinder with very hot clear water dry it completely and apply a light coating of engine oil to prevent rusting Measuring Piston to Bore Clearance Before installing the piston into the cylinder bore it is necessary that the clearance be accurately checked This step is often overlooked and if the clearances are not within specifications engine failure will usually result NOTE Do not use a feeler gauge to measure piston to bore clearance it will yield inaccurate
111. 39 psi 3 If an engine starts hard or turns over but will not start it may indicate a problem with the EFI fuel system A quick test will verify if the system is operating 1 Disconnect and ground the spark plug leads 2 Complete all safety interlock requirements and crank the engine for approximately 3 seconds 3 Remove the spark plugs and check for fuel at the tips a If there is fuel at the tips of the spark plugs the fuel pump and injectors are operating b If there is no fuel at the tips of the spark plugs check the following 1 Make sure the fuel tank contains clean fresh proper fuel 2 Make sure that the vent in the fuel tank is open 3 Make sure the fuel tank valve if so equipped is fully opened 4 Make sure the battery is supplying proper voltage 5 Check that the fuses are good and that no electrical or fuel line connections are damaged or broken 6 Test fuel pump and relay operation as described earlier under Fuel Pump Service Fault Codes The ECU continuously monitors engine operation against preset performance limits If the operation is outside the limits the ECU activates the MIL and stores a diagnostic code in its fault memory If the component or system returns to proper function the ECU will eventually self clear the fault code and turn off the MIL If the MIL stays illuminated it warns the customer that dealer service is required Upon receipt the de
112. 3a Low idle fuel mixture is improperly adjusted Adjust low idle fuel needle b Float level too low Separate fuel bowl from carburetor body Free if stuck or replace float c Idle holes plugged dirt in fuel delivery channels Remove low idle fuel adjusting needle Clean main fuel jet and all passages blow out with compressed air 4 Fuel leaks from carburetor 4a Float stuck See Remedy 2d b Dirt under fuel inlet needle See Remedy 2e c Bowl vents plugged Blow out with compressed air d Carburetor bowl gasket leaks Replace gasket 5 8 Section 5 Fuel System and Governor High Altitude Operation When operating the engine at altitudes of 1500 m 5000 ft and above the fuel mixture tends to get over rich This can cause conditions such as black sooty exhaust smoke misfiring loss of speed and power poor fuel economy and poor or slow governor response To compensate for the effects of high altitude special high altitude jet kits are available The kits include a new main jet slow jet where applicable necessary gaskets and O Rings Refer to the parts manual for the correct kit number Fuel Shut off Solenoid Some carburetors are equipped with an optional fuel shut off solenoid The solenoid is installed in place of the bowl retaining screw The solenoid has a spring loaded pin that retracts when 12 volt current is applied to the lead When it is extended the main fuel jet is blocked preventing normal car
113. 5 CV20 67 CV22 624 cc 69 CV25 75 CV22 23 674 cc 79 CV26 CV730 0001 CV740 0001 CV745 0001 CV750 0001 Complete Spec Number Incorporating Model No with Variation No of Basic Spec or C Serial No Year Manufactured Code Code Year 21 1991 22 1992 23 1993 24 1994 25 1995 26 1996 27 1997 28 1998 29 1999 Factory Code 3305810334 Code Year 30 2000 31 2001 32 2002 33 2003 34 2004 35 2005 36 2006 37 2007 1 4 Section 1 Safety and General Information Oil Recommendations Using the proper type and weight of oil in the crankcase is extremely important So is checking oil daily and changing oil regularly Failure to use the correct oil or using dirty oil causes premature engine wear and failure Oil Type Use high quality detergent oil of API American Petroleum Institute Service Class SG SH SJ or higher Select the viscosity based on the air temperature at the time of operation as shown in the following table Refer to Section 6 Lubrication System for detailed procedures on checking the oil changing the oil and changing the oil filter Fuel Recommendations WARNING Explosive Fuel Gasoline is extremely flammable and its vapors can explode if ignited Before servicing the fuel system make sure there are no sparks open flames or other sources of ignition nearby as these can ignite gasoline vapors Disconnect and ground the spark plug leads to prevent the possi
114. 600 4 Clear 3301 3450 3 Clear 3101 3300 5 Purple 2951 3100 4 Purple 2800 2950 3 Purple 3750 4 Clear 3150 4 Purple Governed Idle Hole 6 5 4 3 2 1 5 Regulation others 10 6 mm Governor Lever and Hole Position RPM Chart Figure 11 78 Throttle Choke Control Bracket Detail Item Description 1 Bracket speed control 2 Clamp cable some applications 3 Kill Switch some applications 4 Lever choke top position 5 Lever throttle control middle 6 Linkage choke control 7 Lever throttle actuator bottom 8 Screw M5x0 8x20 9 Washer wave 10 Washer flat 3 11 Spring choke return 12 Nut M5x0 8 lock 11 24 Section 11 Reassembly 8 mm Governor Lever and Hole Position RPM Chart CV18 Engines Engine Mounted Throttle Control Pivot Shaft Spring Color Hole No Standard Throttle Control High Idle WOT Intended Maximum RPM Spring Color Hole No Orange Green Blue Orange Green Blue Purple Blue Green 4 4 4 3 3 3 2 2 1 3888 3780 3672 3564 3456 3348 3240 3132 3024 3600 3500 3400 3300 3200 3100 3000 2900 2800 Green Blue Orange Clear Red Purple Blue Orange Black 4 4 3 4 3 2 2 1 1 CV20 740 Engines with 0 0299 0 003 in Thick 22 GA Throttle Limiter Engine Mounted Throttle Control Pivot Shaft Spring Color Hole No Standard Throttle Control High Idle WOT Intended Maximum RPM Spring Color Hole No
115. 8 volts or more stator winding is OK If voltage is less than 28 volts test stator using an ohmmeter Tests 3 and 4 3 If resistance is low in both directions the diode is shorted Replace the diode If resistance is high in both directions the diode or stator winding is open Use Test 4 4 If resistance is approximately 1 07 ohms stator winding is OK If resistance is 0 ohms stator winding is shorted Replace stator If resistance is infinity ohms stator winding or lead is open Replace stator 1 Replace burned out lights 2 If voltage is 15 volts or more stator is OK Check for loose connections or shorts in wiring harness If voltage is less than 15 volts test stator using an ohmmeter Test 3 3 If resistance is approximately 0 4 ohms stator is OK If resistance is 0 ohms stator is shorted Replace stator If resistance is infinity ohms stator or lighting lead is open Replace stator 8 24 Section 8 Electrical System and Components Electric Starting Motors Some engines in this series use inertia drive starting motors while most use solenoid shift starters The inertia drive types are covered first and the solenoid shift types following Starting Motor Precautions NOTE Do not crank the engine continuously for more than 10 seconds at a time If the engine does not start allow a 60 second cool down period between starting attempts Failure to follow these guidelines can burn ou
116. A 2A or MA 2B Kohler Part No 24 584 03 should be replaced with 24 584 11 or 24 584 15 S For small modules with vendor numbers MA 2C or MA 2D Kohler Part No 24 584 11 or the larger style modules 24 584 15 S and 24 584 36 S use a digital ohmmeter to check the resistance values and compare them to the table following When testing resistance to the laminations touch the probe to the laminations inside the screw hole as some laminations have a rust preventative coating on the surface which could alter the resistance reading a If all of the resistance values are within the ranges specified in the table go to step 5 b If any of the resistance values are not within the ranges specified in the table that module is faulty and must be replaced NOTE The resistance values apply only to modules that have been on a running engine New service modules may have higher resistance until they have been run Test 3 Check for timing advance Figure 8 9 3 Run the engine at idle and use the timing light beam to locate the line on the screen Draw a line on the blower housing adjacent to the line on the screen Accelerate to full throttle and watch for movement of the line on the screen relative to the line on the blower housing If both cylinders had good spark repeat the test on the other cylinder a If the line on the screen moved away from the line on the blower housing during acceleration the SAM is working properly
117. Cable 2 Disc Spring 3 Ceramic Support Tube 4 Protective Sleeve 5 Contact Element 6 Sensor Housing 7 Active Ceramic Sensor 8 Protective Tube Figure 5B 10 Cutaway of Oxygen Sensor 5B 11 Section 5B EFI Fuel System 5B The oxygen sensor can function only after being heated by exhaust temperatures to a minimum of 375 C 709 F A cold oxygen sensor will require approximately 1 2 minutes at moderate engine load to warm sufficiently to generate a voltage signal Proper grounding is also critical The oxygen sensor grounds through the metal shell so a good solid unbroken ground path back through the exhaust system components engine and wiring harness is required Any disruption or break in the ground circuit can affect the output signal and trigger misleading fault codes Keep that in mind when doing any troubleshooting associated with the oxygen sensor The oxygen sensor can also be contaminated by leaded fuel certain RTV and or other silicone compounds carburetor cleaners etc Use only those products indicated as O2 Sensor Safe Service Like the other sensors already discussed the oxygen sensor is a non serviceable component Complete replacement is required if it is faulty The sensor and wiring harness can be checked as follows NOTE All tests should be conducted with a good quality high impedance digital VOA meter for accurate results 1 Oxygen sensor must be hot minimum of 400 C 752 F R
118. ED 3 06 ENGINE DIVISION KOHLER CO KOHLER WISCONSIN 53044 FOR SALES AND SERVICE INFORMATION IN U S AND CANADA CALL 1 800 544 2444
119. From Crankcase and Remove Oil Filter 1 Remove oil fill cap dipstick and one of the oil drain plugs 9 2 Section 9 Disassembly Figure 9 2 Removing Oil Fill Cap Dipstick 3 Remove the mounting screw and detach the oil fill tube See Figure 9 3 4 Remove and discard the oil filter See Figure 9 4 Remove Oil Cooler If equipped the oil cooler can now be removed from the engine Two different styles are used see Figures 6 6 and 6 7 in Section 6 1 Use a 5 16 allen wrench to remove the oil filter nipple 2 For the crankcase mounted cooler Separate the oil cooler from the oil pan Remove and discard the gasket located between them For the blower housing mounted cooler Separate the filter adapter from the oil pan leaving the oil lines attached Remove the two hex flange screws mounting the oil cooler to the blower housing Remove the cooler lines and filter adapter as an assembly Remove Muffler 1 Remove the exhaust system and attaching hardware from the engine On engines equipped with a port liner remove it now Remove Air Cleaner Assembly Standard Air Cleaner 1 Unhook the latches located on either side of the air cleaner cover or loosen the cover retaining knob and remove the cover See Figure 9 5 Figure 9 3 Removing Oil Fill Tube Bracket Figure 9 4 Removing Oil Filter 2 Allow ample time for the oil to drain from the crankcase and oil filter Figure 9 5 Removing Standard Air Cleaner C
120. H INTAKE VALVE EXHAUST INSERT INTAKE INSERT A B C D E F G H Seat Angle Insert O D Guide Depth Guide I D Valve Head Diameter Valve Face Angle Valve Margin Min Valve Stem Diameter Dimension 89 36 987 37 013 mm 1 4562 1 4572 in 4 mm 0 1575 in 7 038 7 058 mm 0 2771 0 2779 in 33 37 33 63 mm 1 3138 1 3240 in 45 1 5 mm 0 0591 in 6 982 7 000 mm 0 2749 0 2756 in Intake Exhaust 89 32 987 33 013 mm 1 2987 1 2997 in 6 5 mm 0 2559 in 7 038 7 058 mm 0 2771 0 2779 in 29 37 29 63 mm 1 1563 1 1665 in 45 1 5 mm 0 0591 in 6 970 6 988 mm 0 2744 0 2751 in 10 6 Section 10 Inspection and Reconditioning Normal Even after long hours of operation a valve can be reconditioned and reused if the face and margin are in good shape If a valve is worn to where the margin is less than 1 32 do not reuse it The valve shown was in operation for almost 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 valves and is not harmful If the seat is good the valve could be reused after cleaning 10 7 Section 10 Inspection
121. MIL element opened or element shorted to ground b Lamp missing 2 Engine Wiring Harness Related a Broken or shorted wire in harness ECU pin 29 to lamp open or shorted 3 Vehicle Wiring Harness Related a Broken or shorted wire in harness Power lead to MIL open or shorted 4 ECU related a Circuit controlling lamp damaged Code 56 32 Pin MSE 1 1 Plastic Cased ECU only Source Fuel pump relay circuit open shorted to ground or shorted to battery Explanation Fuel pump ignition coils and fuel injectors will not function because the fuel pump relay circuit is either open shorted to ground or may be on continuously if shorted to battery Expected Engine Response Engine will not run or fuel pump will continue to run when switch is off Possible Causes 1 Fuel Pump Relay Related a Bad fuel pump relay Primary side open or shorted 2 Fuel Pump Related a Fuel pump open or shorted internally 3 Engine Wiring Harness related a Fuel pump fuse F1 open b Broken or shorted wire in harness ECU pin 28 to fuel pump relay pin 86 Ignition switch to fuel pump relay pin 85 4 ECU Related a Circuit controlling fuel pump relay damaged 5B 38 Section 5B EFI Fuel System Code 61 Source Explanation Denotes the end of fault codes If signaled first no other fault codes are present Troubleshooting Flow Chart The following flow chart provides an alternative method of troubleshootin
122. Nozzle Left Side 24 Main Jet Right Side 25 Main Jet Left Side 26 Choke Dust Cap 27 Choke Shaft 28 Spring 29 Bushing 30 Choke Lever 31 Choke Plate 32 Choke Plate Screw 2 1 10 17 20 21 18 19 25 12 23 11 14 13 7 24 9 4 2 3 26 15 16 6 5 31 32 27 28 29 8 9 22 30 Figure 5 65 Keihin BK Two Barrel Carburetor Exploded View 5 30 Section 5 Fuel System and Governor Figure 5 66 Governor Controls and Linkage External Initial Adjustment NOTE EFI engines require a special initial adjustment procedure which is covered in subsection 5B Refer to Initial Governor Adjustment in that section for setting the governor on EFI equipped engines Procedure Carburetor Equipped Engines Make this adjustment whenever the governor arm is loosened or removed from the cross shaft See Figure 5 66 and adjust as follows 1 Make sure the throttle linkage is connected to the governor lever and the throttle lever on the carburetor 2 Loosen the hex nut holding the governor lever to the cross shaft 3 Move the governor lever toward the carburetor as far as it will move wide open throttle and hold in position 4 Insert a nail into the hole in the end of the cross shaft and rotate the shaft counterclockwise as far as it will turn then tighten the hex nut securely Adjustments General The governed speed setting is dete
123. Oil Pan Fasteners Install Stator and Backing Plates 1 Apply pipe sealant with Teflon Loctite No 59241 or equivalent to the stator mounting holes 2 Position the stator aligning the mounting holes so that the leads are at the bottom towards the crankcase 3 Install and torque the two hex flange screws to 6 2 N m 55 in lb See Figure 11 20 Install Oil Pan Assembly RTV sealant is used as a gasket between the oil pan and the crankcase on CV17 23 engines CV25 750 engines use an oil pan gasket Refer to Section 2 for a listing of approved sealants Always use fresh sealant Using outdated sealant can result in leakage 1 Be sure the sealing surfaces have been cleaned and prepared as described at the beginning of Section 10 or in Service Bulletin 252 2 Check to make sure that there are no nicks or burrs on the sealing surfaces of the oil pan or crankcase 3 Apply a 1 5 mm 1 16 in bead of sealant to the sealing surface of the oil pan on CV17 23 engines See Figure 11 17 for the sealant pattern On CV25 750 engines use a new gasket Before installing the gasket check the dowel pin on the oil filter side of the crankcase If a split style dowel pin is contained replace it with a closed seam style pin provided with the new gasket Figure 11 17 Oil Pan Sealant Pattern CV17 23 4 Make sure the end of the governor cross shaft is lying against the bottom of cylinder 1 inside the crankcase See Figure 11
124. Removing the crankpin plug when the crankshaft is ground provides easy access for removing any grinding deposits that may collect in the oil passages Use the following procedure to remove and replace the plug Procedure to Remove Crankshaft Plug 1 Drill a 3 16 hole through the plug in the crankshaft 2 Thread a 3 4 or 1 long self tapping screw with a flat washer into the drilled hole The flat washer must be large enough to seat against the shoulder of the plug bore See Figure 10 2 3 Tighten the self tapping screw until it draws the plug out of the crankshaft Procedure to Install New Plug 1 Use a single cylinder camshaft pin Part No 47 380 09 S as a driver and tap the plug into the plug bore until it seats at the bottom of the bore Make sure the plug is tapped in evenly to prevent leakage Inspect the crankshaft bearing surfaces for scoring grooving etc Measure the running clearance between the crankshaft journals and their respective bearing bores Use an inside micrometer or telescoping gauge to measure the inside diameter of both bearing bores in the vertical and horizontal planes Use an outside micrometer to measure the outside diameter of the crankshaft main bearing journals Subtract the journal diameters from their respective bore diameters to get the running clearances Check the results against the specifications in Section 1 If the running clearances are within specification and there is no evidence of
125. SERVICE MANUAL VERTICAL CRANKSHAFT COMMAND CV17 750 Contents Section 1 Safety and General Information Section 2 Tools amp Aids Section 3 Troubleshooting Section 4 Air Cleaner and Air Intake System Section 5 Fuel System and Governor Section 5B Electronic Fuel Injection EFI Fuel System Section 6 Lubrication System Section 7 Retractable Starter Section 8 Electrical System and Components Section 9 Disassembly Section 10 Inspection and Reconditioning Section 11 Reassembly
126. See Figure 9 46 Figure 9 46 Removing Valves with Valve Spring Compressor 3 Once the valve spring is compressed remove the following items See Figures 9 47 and 9 48 Valve spring keepers Valve spring retainers Valve springs Valve spring caps Intake and exhaust valves mark position Valve stem seal intake valve only Figure 9 48 Intake Valve Seal Location NOTE These engines use valve stem seals on the intake valves Use a new seal whenever the valve is removed or if the seal is deteriorated or damaged in any way Never reuse an old seal 4 Repeat the above procedure for the other cylinder head Do not interchange parts from one cylinder head to the other Remove Grass Screen and Fan 1 On engines with a flat plastic screen small metal retainers are typically attached on three of the seven mounting posts for positive retention of the plastic grass screen Use a hook end tool next to the post and pull outward to separate each of the small metal retainers Then unsnap the screen from the mounting posts See Figure 9 49 Figure 9 47 Valve Components Valve Keepers Cap Spring Retainer Valve Seal 9 14 Section 9 Disassembly Figure 9 51 Removing Flywheel Fastener Using Strap Wrench 2 Remove the hex flange screw and washer 3 Use a puller to remove the flywheel from the crankshaft See Figure 9 52 NOTE Always use a flywheel puller to remove the flywheel fro
127. Service Kit see Section 2 has an integral relief valve Connect the black tester hose to the test valve in the fuel rail Route the clear hose into a portable gasoline container Depress the button on the tester relief valve Initial Starting Priming Procedure Important The EFI fuel system must be purged of air primed prior to the initial start up and or any time the system has been disassembled or the fuel tank run dry 1 Locate the electronic control unit ECU for the EFI system Check the part number on the end If the Part No is 24 584 28 or higher the ECU has a built in priming feature a Turn the key switch to the on run position You will hear the fuel pump cycle on and off When the fuel pump stops cycling approximately one minute the system is primed start the engine Description 2 For plastic cased ECU s below 24 584 28 S the system can be primed by manually cycling the fuel pump a Turn the key switch to the on run position The fuel pump will run for about three seconds and stop Turn the switch off and back on to restart the fuel pump Repeat this procedure until the fuel pump has cycled five times then start the engine 3 The system can also be primed similar to relieving pressure a Connect the pressure gauge as described above for relieving fuel pressure Depress and hold the release button and crank the engine until the air is purged and fuel is visible in the discharge tube
128. Starter 1 Remove the five hex flange screws securing the starter to the blower housing 2 Remove the starter To Install Starter 1 Install the retractable starter onto the blower housing leaving the five hex flange screws slightly loose Figure 7 2 Removing Starter Handle 3 Remove the rope retainer from inside the starter handle Untie the single knot and remove the rope retainer and handle 4 Hold the pulley firmly and untie the slipknot Allow the pulley to rotate slowly as the spring tension is released 5 When all spring tension on the starter pulley is released remove the rope from the pulley 2 Pull the starter handle out until the pawls engage in the drive cup Hold the handle in this position and tighten the screws securely Rope Replacement The rope can be replaced without complete starter disassembly 1 Remove the starter from the blower housing 2 Pull the rope out approximately 12 in and tie a temporary slip knot in it to keep it from retracting into the starter See Figure 7 2 Slipknot Handle Knot Rope Retainer 7 2 Section 7 Retractable Starter 6 Tie a single knot in one end of the new rope 7 Rotate the pulley counterclockwise when viewed from pawl side of pulley until the spring is tight approximately 6 full turns of pulley 8 Rotate the pulley clockwise until the rope hole in the pulley is aligned with the rope guide bushing of the starter housing
129. T E S el b alia v A t n e n o p m o C la u d iv i d n I tfi h S d io n elo S lo o T g n i d lo H h s u r B r etr a t S 6 1 4 2 8 R L K slo o T E S e v itc u d n I l a ti g i D r e t e m o h c a T e n i g n e n a f o M P R d e e p s g n it a r e p o g n i k c e h c r o F c n I y g olo n h c e T n g is e D 0 1 1 I T D r e ts e T e r u s s e r P m u u c a V r ete m o n a m r et a w a o t e v it a n r etl A S 2 2 1 6 7 5 2 r el h o K s e ir e S M amp K r e m a e R e d i u G e v l a V n oit alla ts n i r etf a s e d i u g e v la v g n izis r o F 3 1 4 2 8 R L K slo o T E S C H O d n a m m o C si g e A e g a r u o C ti K e ci v r e S e d i u G e v l a V s e d i u g e u la v n r o w g n iciv r e s r o F 5 1 4 2 8 R L K slo o T E S 2 3 Section 2 Tools amp Aids 2 s d i A n o it p ir c s e D o N tr a P e c r u o S t n a cir b u L tf a h s m a C 3 1 6 Z Z r a p sla V S 4 1 7 5 3 5 2 r el h o K e s a e r G cirtc e l e i D 1 6 6 G d r a u g a v o N E G S 1 1
130. Using an abrasive cut off wheel cut out a six tooth segment of the ring gear as shown 2 Grind off any burrs or sharp edges 3 Invert the segment and place it between the ignition bosses on the crankcase so that the tool teeth engage the flywheel ring gear teeth The bosses will lock the tool and flywheel in position for loosening tightening or removing with a puller Figure 2 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 capscrew with the correct thread size to match the threads in the connecting rod 4 Use a flat washer with the correct I D to slip on the capscrew and approximately 1 O D Kohler Part No 12 468 05 S Assemble the capscrew and washer to the joint surface of the rod as shown in Figure 2 2 Figure 2 2 Rocker Arm Crankshaft Tool 3 1 Section 3 Troubleshooting 3 Section 3 Troubleshooting Troubleshooting Guide When troubles occur be sure to check the simple causes which at first may seem too obvious to be considered For example a starting problem could be caused by an empty fuel tank Some general common causes of engine troubl
131. Y 3 2 1 0 6 0 P U C E e vitc e f e D Y Y 4 2 r o s n e S d e e p S e n ig n E Y Y 9 1 3 4 7 1 0 P n a e L o o t m e ts y S Y Y 6 Continue on next page 5B 32 Section 5B EFI Fuel System k n il B e d o C 2 D B O e d o C P elb a cilp p A n i P 2 3 o t 1 1 E S M ts y S U C E yln O m e n o it p ir c s e D e r ulia F r o n o itc e n n o C n i P 4 2 0 1 E S M d e s a C cits al P m e ts y S U C E n i P 2 3 1 1 E S M d e s a C cits al P m e ts y S U C E e t o N 1 3 2 3 1 0 P O2 y r e tt a B o t d e tr o h S tiu c ri C r o s n e S N Y 3 2 3 4 3 1 0 P O2 d e tc e t e D ytivitc A o N tiu c ri C r o s n e S N N 8 3 3 5 7 1 0 P h ci R o o t m e ts y S Y Y 8 7 3 3 0 2 0 0 P O2 ti m iL r e p p U t a lo rtn o C r o s n e S Y Y 8 4 3 1 7 1 0 P d e h c a e R ti m iL n o it p a d A m u m ix a M Y Y 8 4 3 2 7 1 0 P d e h c a e R ti m iL n o it p a d A m u m in i M Y Y 8 2 4 7 1 1 0 P o t d e tr o h S tiu c ri C r o s n e S e r u t a r e p m e T d n u o r G Y Y 2 4 8 1 1
132. Y MAINTENANCE AND ADJUSTMENTS 1 800 544 2444 www kohlerengines com FAMILY 6 KHXS 7252 PH TYPE APP DISPL CC MODEL NO SPEC NO SERIAL NO BUILD DATE OEM PROD NO IMPORTANT ENGINE INFORMATION THIS ENGINE MEETS U S EPA AND CA 2005 AND LATER AND EC STAGE II SN 4 EMISSION REGS FOR SI SMALL OFF ROAD ENGINES N11236 5 3 Section 5 Fuel System and Governor 5 Troubleshooting Fuel System Related Causes Test Conclusion 1 Check the following a Make sure the fuel tank contains clean fresh proper fuel b Make sure the vent in fuel tank cap is open c Make sure the fuel valve is open d Make sure vacuum and fuel lines to fuel pump are secured and in good condition 2 Check for fuel in the combustion chamber a Disconnect and ground spark plug leads b Close the choke on the carburetor c Crank the engine several revolutions d Remove the spark plug and check for fuel at the tip 2 If there is fuel at the tip of the spark plug fuel is reaching the combustion chamber If there is no fuel at the tip of the spark plug check for fuel flow from the fuel tank Test 3 3 Check for fuel flow from the tank to the fuel pump a Remove the fuel line from the inlet fitting of fuel pump b Hold the line below the bottom of the tank Open the shut off valve if so equipped and observe flow 3 If fuel does flow from the line check for faulty fuel pump Test 4 If fuel does not f
133. ads should overlap between the terminals to form a solid bridge of compound See Figure 11 50 Do not put any compound inside the terminals The 24 584 15 S ignition modules have a separator barrier between the terminals On these modules seal the base of the terminals but it is not necessary to have overlapping beads of sealant between the connections Figure 11 50 Sealant Applied to Terminals 2 Connect the kill lead to the tab terminal on standard ignition modules See Figure 11 51 Figure 11 53 Breather Cover and Gasket RTV sealant was used on early models between the breather cover and the crankcase A gasket with imprinted sealant beads is now used and recommended See Figure 11 53 Install as follows 1 Be sure the sealing surfaces of the crankcase and breather cover are clean of old gasket material or RTV sealant Do not scrape the surfaces as this could result in leakage 2 Check to make sure there are no nicks or burrs on the sealing surfaces 3 Position the breather gasket and cover on the crankcase Install the first two hex flange screws in locations 3 and 4 shown in Figure 11 54 Finger tighten at this time Figure 11 51 Connecting Kill Leads on Standard Ignition Modules Figure 11 52 Connect Leads on SMART SPARK Ignition Modules Install Breather Cover and Inner Baffles Sealant 11 16 Section 11 Reassembly Install Blower Housing and Outer Baffles NOTE Do not completely tight
134. ady voltage from 350 550 mv 0 35 0 55 v a If the voltage reading is not as specified move the black voltmeter lead to the negative post of the battery to be certain of a good ground If the voltage is still not correct the ECU is probably bad b If the voltage readings are correct clear the fault codes and run the engine to check if any fault codes reappear To Replace Oxygen Sensor 1 Disconnect the oxygen sensor connector from the wiring harness 2 Loosen and remove the oxygen sensor from the exhaust manifold muffler assembly 3 Apply anti seize compound sparingly to threads of new oxygen sensor if none already exists DO NOT get any on the tip as it will contaminate the sensor Install sensor and torque to 50 60 N m 37 44 ft lb 4 Reconnect the lead to the wiring harness connector Make sure it can not contact hot surfaces moving parts etc 5 Test run the engine Electrical Relay Figure 5B 11 Electrical Relay General The electrical relay is used to supply power to the injectors coil and fuel pump When the key switch is turned on and all safety switch requirements met the relay provides 12 volts to the fuel pump circuit injectors and ignition coils The fuel pump circuit is continuously grounded so the pump is immediately activated and pressurizes the system Activation of the ignition coils and fuel injectors is controlled by the ECU which grounds their respective ground ci
135. ain Nozzles Main Jets Slow Idle Fuel Jets O Ring 5 26 Section 5 Fuel System and Governor Figure 5 57 Installing Float Assembly 14 Hold the carburetor body so the float assembly hangs vertically and rests lightly against the fuel inlet needle The inlet needle should be fully seated but the center pin of the needle on retainer clip end should not be depressed Check the float height adjustment NOTE The inlet needle center pin is spring loaded Make sure the float rests against the fuel inlet needle without depressing the center pin 15 The correct float height setting is 17 mm 0 669 in 1 5 mm 0 059 in measured from the float bottom to the body of the carburetor See Figure 5 58 Replace the float if the height is different than the specified setting Do not attempt to adjust by bending float tab Figure 5 56 Float and Inlet Needle Details 13 Install the float and inlet needle down into the seat and carburetor body Install the new pivot pinthrough the float hinge and secure with the new retaining screw See Figure 5 57 Figure 5 54 Installing Main Nozzles and Main Jets 9 Make sure the O Ring near the bottom of each slow jet is new or in good condition Align and insert the two slow jets into the top of carburetor See Figure 5 53 10 Install the large flat retaining washer and secure with the mounting screw attaching the ground lead if originally secured by the screw 11 Instal
136. al in relay connector see Figure 5B 12 Set meter to test resistance Rx1 Turn ignition switch from off to on Meter should indicate continuity ground circuit is completed for 1 to 3 seconds Turn key switch back off a Clean the connection and check wiring if circuit was not completed Figure 5B 13 Relay Terminal Details 5 Connect an ohmmeter Rx1 scale between the 85 and 86 terminals in the relay There should be continuity See Figure 5B 13 6 Attach ohmmeter leads to the 30 and 87 terminals in relay First there should be no continuity Using a 12 volt power supply connect the positive lead to the 85 terminal and touch the negative lead to the 86 terminal When 12 volts is applied the relay should activate and continuity should exist between the 30 and 87 terminals Repeat the test several times If at any time the relay fails to activate the circuit replace the relay Fuel Injectors 5B 14 Section 5B EFI Fuel System 1 Filter Strainer In Fuel Supply 2 Electrical Connection 3 Solenoid Winding Multi Orifice Director Plate With Calibrated Opening 4 Valve Housing 5 Armature 6 Valve Body 7 Valve Needle 1 2 3 4 5 6 7 Figure 5B 15 Style 2 Fuel Injector General The fuel injectors mount into the throttle body intake manifold and the fuel rail attaches to them at the top end Replaceable O Rings on both ends of the injector prevent external fuel
137. aler technician can access the fault code s to help determine what portion of the system is malfunctioning The 2 digit fault codes available based upon the style of ECU are listed on pages 5B 31 5B 32 The codes are accessed through the key switch and displayed as blinks or flashes of the MIL Access the codes as follows 1 Start with the key switch off 2 Turn the key switch on off on off on leaving it on in the third sequence The time between sequences must be less than 2 5 seconds 3 Any stored fault codes will then be displayed as a series of MIL blinks from 2 to 6 representing the first digit followed by a pause and another series of blinks from 1 to 6 for the second digit see Figure 5B 40 a It s a good idea to write down the codes as they appear as they may not be in numerical sequence b Code 61 will always be the last code displayed indicating the end of code transmission If code 61 appears immediately no other fault codes are present 5B 31 Section 5B EFI Fuel System 5B Long Pause Short Pause Code 32 3 2 Code 61 1 6 Long Pause Light remains on at end of transmission 1 Diagnostic display initiated through ignition key sequencing 2 Figure 5B 40 After the problem has been corrected the fault codes may be cleared as follows 1 Disconnect the negative battery cable or the main harness connector for one minute 2 Reconnect the cable and tighten secur
138. als is processed by the ECU and compared to the internal pre programmed maps to determine the required fuel and ignition settings for the amount of load The correct position of the TPS is established and set at the factory Do not loosen the TPS or alter the mounting position unless absolutely required by fault code diagnosis or throttle shaft service If the TPS is loosened or repositioned the appropriate TPS Initialization Procedure must be performed to reestablish the baseline relationship between the ECU and the TPS Service The TPS is a sealed non serviceable assembly If diagnosis indicates a bad sensor complete replacement is necessary If a blink code indicates a problem with the TPS it can be tested as follows 1 Counting the number of turns back out the idle speed adjusting screw counterclockwise until the throttle plates can be closed completely 2 Disconnect the main harness connector from the ECU but leave the TPS mounted to the throttle body manifold 3 a Use an ohmmeter and connect the ohmmeter leads as follows to test See chart on page 5B 26 or 5B 29 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 b Hold the throttle closed and check the resistan
139. an assembly with the throttle shaft TPS throttle plates and idle speed adjusting screw installed The throttle shaft rotates on needle bearings non serviceable capped with rubber seals to prevent air leaks A throttle shaft repair kit is available to replace the shaft if worn or damaged The appropriate TPS Initialization Procedure must be performed after any throttle shaft service Idle Speed Adjustment RPM General The idle speed is the only adjustment that may be performed on the EFI system The standard idle speed setting for EFI engines is 1500 RPM but certain applications might require a different setting Check the equipment manufacturer s recommendation For starting and warm up the ECU will adjust the fuel and ignition timing based upon ambient temperature engine temperature and loads present In cold conditions the idle speed will probably be higher than normal for a few moments Under other conditions the idle speed may actually start lower than normal but gradually increase to the established setting as operation continues Do not attempt to circumvent this warm up period or readjust the idle speed during this time The engine must be completely warmed up in closed loop operating mode for accurate idle adjustment Adjustment Procedure 1 Make sure there are no fault codes present in the ECU memory 2 Start the engine and allow it to fully warm up and establish closed looped operation approxim
140. and the choke plate for correct reassembly later See Figure 5 35 Remove the two screws attaching the choke plate to the choke shaft Pull the shaft out of the carburetor body and discard the removed parts Figure 5 35 Choke Details 5 Use a screw extractor easy out and remove the original choke shaft bushing with the old choke lever from the carburetor housing Save the bushing to use as a driver for installing the new bushing Discard the old lever 6 Clean the I D of both choke shaft bores as required 7 Insert the new bushing through the new choke lever from the outside and start the bushing in the outer shaft bore Position the choke lever so that the protruding boss on the carburetor housing is between the two stops formed in the choke lever See Figure 5 36 Figure 5 36 Assembling Choke Lever 8 Turn the old bushing upside down and use it as a driver to carefully press or tap the new bushing into the carburetor body until it bottoms Check that the choke lever pivots freely without restriction or binding See Figure 5 37 Figure 5 37 Installing Bushing 5 20 Section 5 Fuel System and Governor Figure 5 38 Choke Shaft and Spring Details 10 Slide the choke shaft and spring into the carburetor Pivot preload the shaft and set the inner leg of the spring against the formed stop within the choke lever as originally assembled See Figure 5 35 The opposing leg of the spring must still be between the
141. ange screws engines with plastic grass screen NOTE Position the locating tabs on the back of the fan in the recesses of the flywheel See Figure 11 26 2 Torque the screws to 9 9 N m 88 in lb Figure 11 27 Installing Plastic Grass Screen Install Supports for the Metal Grass Screen 1 If a metal grass screen is used with threaded individual supports install a spacer washer on the external threads Apply blue Loctite No 242 removable to the threads Install the four supports as shown in Figure 11 28 11 9 Section 11 Reassembly 11 Figure 11 28 Installing Supports for Metal Grass Screen 2 Tighten the supports with a torque wrench to 9 9 N m 99 in lb See Figure 11 29 The grass screen will be installed to the supports after the blower housing is in place Figure 11 30 Applying Camshaft Lubricant to Bottom of Lifters 3 Note the mark or tag identifying the hydraulic lifters as either intake or exhaust and cylinder 1 or cylinder 2 Install the hydraulic lifters into their appropriate locations in the crankcase Do not use a magnet See Figure 11 31 NOTE Hydraulic lifters should always be installed in the same position as before disassembly The exhaust lifters are located on the output shaft oil pan 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 11
142. ankcase breather Rings or cylinder worn Air escaping from exhaust system Defective exhaust valve improper seating Air escaping from carburetor 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 replacement Gauge reading in high red zone Rings and or cylinder have considerable wear Engine should be reconditioned or replaced Leakdown Test Results 4 1 Section 4 Air Cleaner and Air Intake System 4 Section 4 Air Cleaner and Air Intake System Air Cleaners General These engines are equipped with a replaceable high density paper air cleaner element Most are also equipped with an oiled foam precleaner which surrounds the paper element Three different types are used The standard type air cleaner is shown in Figure 4 1 The commercial mower type is shown in Figure 4 2 and the heavy duty air cleaner is shown in Figure 4 9 Figure 4 1 Standard Air Cleane
143. ar and check for freedom of movement Make sure there is no binding If binding occurs loosen the screws reposition the pump retorque the hex flange screws and recheck the movement Crankcase Breather System The breather system is designed to control the amount of oil in the head area and still maintain the necessary vacuum in the crankcase Figure 10 20 Oil Separator Governor Cross Shaft Oil Seal If the governor cross shaft seal is damaged and or leaks replace it using the following procedure Remove the oil seal from the crankcase and replace it with a new one Install the new seal to the depth shown in Figure 10 21 using a seal installer Figure 10 19 Crankcase with Breather Reed A spring steel reed and stop is mounted on each bank of the crankcase between the lifter bores See Figure 10 19 When the pistons move downward air is pushed past the reeds into the cylinder head cavities On the 2 cylinder the upper end of the head is completely sealed by the rocker cover so a low positive pressure is created in the head cavity The 1 rocker cover has a hole in it for venting The bottom nipple of an oil separator canister is fitted into the hole with a grommet From the top nipple of the canister a breather hose goes back to the air cleaner base The air moving into the 1 head cavity is filtered through the oil separator and then is drawn into the air intake See Figure 10 20 The upward travel of the pistons closes
144. area around all joints and relieve any pressure before starting any disassembly Fuel Line Locking Cups Fuel Rail TPS Fuel Injector Figure 5B 31 High Pressure Fuel Line 5B 22 Section 5B EFI Fuel System General Special low permeation high pressure fuel line with an SAE 30 R9 rating is required for safe and reliable operation due to the higher operating pressure of the EFI system If hose replacement is necessary order Fuel Line Service Kit Part No 25 111 37 S containing 60 of high pressure hose and 10 Oetiker clamps or use only the type of hose specified Special Oetiker clamps Kohler Part No 24 237 05 S are used on all fuel line connections to prevent tampering and safety hazards with the high fuel pressure The old clamp must be cut to open a connection so replacement is necessary each time Oetiker Clamp Pliers part of EFI Service Kit see Section 2 is used to crimp the replacement clamps CAUTION Fuel lines between the fuel pump and fuel rail must be made from SAE 30 R9 fuel line Standard fuel line SAE 30 R7 may only be used between the fuel tank and pump 5 16 ID and for the return line from the pressure regulator to the tank 1 4 ID All high pressure fuel line connections must be secured with Oetiker clamps Kohler Part No 24 237 05 S installed crimped with the corresponding pliers Throttle Body Intake Manifold Assembly Service The throttle body intake manifold is serviced as
145. ately 5 10 min 3 Place the throttle control in the idle slow position and check the idle speed with a tachometer Turn the idle speed screw in or out as required to obtain 1500 RPM or the idle speed specified by the equipment manufacturer See Figure 5B 33 4 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 specified by the equipment manufacturer Figure 5B 32 Upper Throttle Body Intake Manifold Details General The EFI engines have no carburetor so the throttle function regulate incoming combustion airflow is incorporated in the intake manifold assembly The manifold consists of a one piece aluminum casting which also provides mounting for the fuel injectors throttle position sensor fuel rail air baffle idle speed screw and air cleaner assembly 5B 23 Section 5B EFI Fuel System 5B Figure 5B 33 Idle Speed Screw Details Initial Governor Adjustment The initial governor adjustment is especially critical on EFI engines because of the accuracy and sensitivity of the electronic control system Incorrect adjustment can result in overspeed loss of power lack of response or inadequate load compensation If you encounter any of these symptoms and suspect them to be related to the governor setting the following should be used to check and or adjust the
146. ater than 35 C 86 F b The oxygen sensor has warmed sufficiently to provide a signal minimum 375 C 709 F c Engine operation is at a steady state not starting warming up accelerating etc During closed loop operation the ECU has the ability to readjust temporary and learned adaptive controls providing compensation for changes in overall engine condition and operating environment so it will be able to maintain the ideal air fuel ratio of 14 7 1 The system requires a minimum engine oil temperature greater than 55 C 130 F to properly adapt These adaptive values are maintained as long as the ECU is powered up by the battery 5B 4 Section 5B EFI Fuel System During certain operating periods such as cold starts warm up acceleration etc an air fuel ratio richer than 14 7 1 is required and the system operates in an open loop mode In open loop operation the oxygen sensor output is not used and the controlling adjustments are based on the primary sensor signals and programmed maps only The system operates open loop whenever the three conditions for closed loop operation above are not being met Important Service Notes Cleanliness is essential and must be maintained at all times when servicing or working on the EFI system Dirt even in small quantities can cause significant problems Clean any joint or fitting with parts cleaning solvent before opening to prevent
147. ating conditions The ECU then sends output signals to set the injector duration and ignition timing The ECU continually performs a diagnostic check of itself each of the sensors and the system performance If a fault is detected the ECU turns on the Malfunction Indicator Light MIL on the equipment control panel stores the fault code in its fault memory and goes into a default operating mode Depending on the significance or severity of the fault normal operation may continue or limp home operation slowed speed richer running may be initiated A technician can access the stored fault code using a blink code diagnosis flashed out through the MIL An optional computer software diagnostic program is also available see Section 2 The ECU requires a minimum of 7 0 volts to operate The adaptive memory in the ECU is operational whenever the required voltage is present however the adapted values are lost if the power supply is disrupted for any reason The ECU will relearn the adapted values if the engine is operated for 10 15 minutes at varying speeds and loads after the oil temperature exceeds 55 C 130 F To prevent engine over speed and possible 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 maximu
148. before completion of the test cycle Otherwise a false reading may be displayed in the form of a or a faint 8 8 15 8 Section 8 Electrical System and Components 15 20 25 Amp Regulated Charging System Figure 8 17 Wiring Diagram 15 20 25 Amp Regulated Battery Charging System with Fixed Timing 8 16 Section 8 Electrical System and Components Figure 8 19 15 Amp Stator and Rectifier Regulator Figure 8 20 20 Amp Stator and Rectifier Regulator Figure 8 18 Wiring Diagram 15 20 25 Amp Regulated Battery Charging System with Variable Ignition Timing SMART SPARK 8 17 8 Section 8 Electrical System and Components Ground To Kill Lead White Diode Keyswitch Optional Oil SentryTM Switch Indicator Light Optional Oil SentryTM Switch Shutdown 12 V Battery Solenoid Starter Lights Yellow Black 3 Amp 70 Watt Flywheel Stator Ignition Modules Spark Plug Red Blue R A S B GND Light Optional Fuse Optional Ammeter Spark Plug Figure 8 21 25 Amp Stator and Rectifier Regulators 3 Amp Unregulated Charging System 1st Style 2nd Style 25 Amp Stator Figure 8 22 Wiring Diagram 3 Amp Unregulated Battery Charging System 70 Watt Lighting 8 18 Section 8 Electrical System and Components Figure 8 23 3 Amp 70 Watt Stator Stator The stator is mounted on the crankcase behind the flywheel Follow the procedures in Section 9
149. bility of sparks from the ignition system General Recommendations Purchase gasoline in small quantities and store in clean approved containers A container with a capacity of 2 gallons or less with a pouring spout is recommended Such a container is easier to handle and helps eliminate spillage during refueling Do not use gasoline left over from the previous season to minimize gum deposits in your fuel system and to ensure easy starting Do not add oil to the gasoline Do not overfill the fuel tank Leave room for the fuel to expand Fuel Type For best results use only clean fresh unleaded gasoline with a pump sticker octane rating of 87 or higher In countries using the Research method it should be 90 octane minimum Unleaded gasoline is recommended as it leaves less combustion chamber deposits and reduces harmful exhaust emissions Leaded gasoline is not recommended and must not be used on EFI engines or on other models where exhaust emissions are regulated Gasoline Alcohol blends Gasohol up to 10 ethyl alcohol 90 unleaded gasoline by volume is approved as a fuel for Kohler engines Other gasoline alcohol blends are not approved Gasoline Ether blends Methyl Tertiary Butyl Ether MTBE and unleaded gasoline blends up to a maximum of 15 MTBE by volume are approved as a fuel for Kohler engines Other gasoline ether blends are not approved NOTE Using other than service class SG SH SJ or higher oil or
150. buretor operation Below is a simple test made with the engine off that can determine if the solenoid is functioning properly 1 Shut off the fuel and remove the solenoid from the carburetor When the solenoid is loosened and removed gas will leak out of the carburetor Have a container ready to catch the fuel The main jet is mounted in the tip of the solenoid pin Be careful that it does not get damaged while the solenoid is separated from the carburetor 2 Wipe the tip of the solenoid with a shop towel or blow it off with compressed air to remove any remaining fuel Take the solenoid to a location with good ventilation and no fuel vapors present You will also need a 12 volt power source that can be switched on and off 3 Be sure the power source is switched off Connect the positive power source lead to the red lead of the solenoid Connect the negative power source lead to the solenoid body 4 Turn the power source on and observe the pin in the center of the solenoid The pin should retract with the power on and return to its original position with the power off Test several times to verify operation Figure 5 5 Fuel Shut off Solenoid Location Carburetor Adjustments CV17 740 General The carburetor is designed to deliver the correct fuel to air mixture to the engine under all operating conditions The high speed mixture adjustment is set at the factory and cannot be adjusted The low idle fuel
151. ce It should be 800 1200 4 Leave the leads connected to the pin terminals as described in step 3 Rotate the throttle shaft slowly counterclockwise to the full throttle position Monitor the dial during rotation for indication of any momentary short or open circuits Note the resistance at the full throttle position It should be 1800 3000 5 Disconnect the main wiring harness connector from the TPS leaving the TPS assembled to the manifold Refer to the chart below and perform the resistance checks indicated between the terminals in the TPS switch with the throttle in the positions specified If the resistance values in steps 3 4 and 5 are within specifications go to step 6 If the resistance values are not within specifications or a momentary short or open circuit was detected during rotation step 4 the TPS needs to be replaced go to step 7 6 Check the TPS circuits input ground between the TPS plug and the main harness connector for continuity damage etc See chart on page 5B 26 or 5B 29 Throttle Position Closed C losed Full Full Any Between Terminals 2 amp 3 1 amp 3 2 amp 3 1 amp 3 1 amp 2 Resistance Value 800 1200 1800 3000 1800 3000 800 1200 1600 2500 Continuity Yes Yes Yes Yes Yes 5B 8 Section 5B EFI Fuel System Figure 5B 7 Service Connector Plug Plastic Cased ECU Harness 8 Hold the throttle against the idle speed
152. ch carburetion weak ignition overextended oil change intervals or wrong weight or type of oil was used to name a few NOTE It is good practice to drain oil at a location away from the workbench Be sure to allow ample time for complete drainage Cleaning the Engine After inspecting the external condition of the engine clean the engine thoroughly before disassembling it Also clean individual components as the engine is disassembled Only clean parts can be accurately inspected and gauged for wear or damage There are many commercially available cleaners that will quickly remove grease oil and grime from engine parts When such a cleaner is used follow the manufacturer s instructions and safety precautions carefully Make sure all traces of the cleaner are removed before the engine is reassembled and placed into operation Even small amounts of these cleaners can quickly break down the lubricating properties of engine oil Basic Engine Tests Crankcase Vacuum Test A partial vacuum should be present in the crankcase when the engine is operating Pressure in the crankcase normally caused by a clogged or improperly assembled breather can cause oil to be forced out at oil seals gaskets or other available spots Crankcase vacuum is best measured with either a water manometer or a vacuum gauge see Section 2 Complete instructions are provided in the kits To test the crankcase vacuum with the manometer 1 Insert th
153. d ECU Circuit 25 2 Relay circuit s problem 24 Pin MSE 1 0 Plastic Cased ECU Circuits 18 85 30 and 87 32 Pin MSE 1 1 Plastic Cased ECU Circuits 28 85 30 and 87 3 Relay 4 ECU grounds 5 ECU Diagnostic Aid 7 IGNITION SYSTEM no spark Possible causes 1 Spark plug 2 Plug wire 3 Coil 4 Coil circuit s 24 Pin MSE 1 0 Plastic Cased ECU Circuits 22 23 65 66 30 and relay 32 Pin MSE 1 1 Plastic Cased ECU Circuits 30 31 65 66 relay and relay circuit 30 5 ECU grounds 6 ECU Diagnostic Aid 8 FUEL SYSTEM ELECTRICAL no fuel delivery Possible causes 1 No fuel 2 Air in fuel rail 3 Fuel valve shut off 4 Fuel filter line plugged 5 Injector circuit s 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 6 Injector 7 ECU grounds 8 ECU Diagnostic Aid 9 FUEL SYSTEM fuel pressure Possible causes for low fuel system pressure 1 Low fuel 2 Fuel filter plugged 3 Fuel supply line plugged 4 Pressure regulator 5 Fuel pump Possible causes for high fuel system pressure 1 Pressure regulator 2 Fuel return line plugged or restricted Diagnostic Aid 10 BASIC ENGINE cranks but will not run Possible causes 1 Refer to basic engine troubleshooting charts within service manual sections 3 5 and 8 6 1 Section 6 Lubr
154. diately 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 8 3 8 Section 8 Electrical System and Components 2 Keep the cables terminals and external surfaces of the battery clean A build up of corrosive acid or grime on the external surfaces can cause the battery to self discharge Self discharge occurs rapidly when moisture is present 3 Wash the cables terminals and external surfaces with a mild baking soda and water solution Rinse thoroughly with clear water NOTE Do not allow the baking soda solution to enter the cells as this will destroy the electrolyte Battery Test To test the battery you will need a DC voltmeter Perform the following steps see Figure 8 2 1 Connect the voltmeter across the battery terminals 2 Crank the engine If the battery drops below 9 volts while cranking the battery is too small discharged or faulty Battery General A 12 volt battery with 400 cold cranking amps 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 the following table for minimum cold cranking amp cca capacities based on anticipated ambient temperatures The actual co
155. dirt from entering the system Always depressurize the fuel system through the test valve in the fuel rail before disconnecting or servicing any fuel system components See fuel warning on page 5B 2 Never attempt to service any fuel system component while the engine is running or the ignition switch is on Do not use compressed air if the system is open Cover any parts removed and wrap any open joints with plastic if they will remain open for any length of time New parts should be removed from their protective packaging just prior to installation Avoid direct water or spray contact with system components Do not disconnect or reconnect the main ECU wiring harness connector or any individual components with the ignition on This can send a damaging voltage spike through the ECU Do not allow the battery cables to touch opposing terminals When connecting battery cables attach the positive cable to the positive battery terminal first followed by the negative cable to the negative battery terminal Never start the engine when the cables are loose or poorly connected to the battery terminals Never disconnect the battery while the engine is running Never use a quick battery charger to start the engine Do not charge the battery with the key switch on Always disconnect the negative battery cable before charging the bat
156. e Full Throttle position Insert a 1 52 mm 0 060 in feeler gauge between the tang of the throttle shaft plate and the underside of the manifold boss Use a locking pliers needle nose works best to temporarily clamp the parts in this position See Figure 5B 36 3 Rotate the governor lever and shaft counterclockwise until it stops Use only enough pressure to hold it in that position 4 Check how the end of the throttle linkage aligns with the bushing hole in the governor lever See Figure 5B 37 It should fall in the center of the hole If it doesn t perform the adjustment procedure as follows Figure 5B 38 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 3 Insert a nail into the hole in the top of the cross shaft Using light pressure rotate the governor shaft counterclockwise as far as it will turn then torque the hex nut on the clamping screw to 6 8 N m 60 in lb See Figure 5B 39 Make sure that the governor arm has not twisted up or down after the nut has been tightened B Setting the Initial Adjustment 1 Check the split where the clamping screw goes through the governor lever See Figure 5B 38 There should be a gap of at least 1 32 If the tips are touching and there is
157. e stopper hose into the oil fill hole Leave the other tube of manometer open to atmosphere Make sure the shut off clamp is closed 2 Start the engine and run at no load high speed 3200 to 3750 RPM 3 Open the clamp and note the water level in the tube The level in the engine side should be a minimum of 10 2 cm 4 in above the level in the open side If the level in the engine side is less than specified low no vacuum or the level in the engine side is lower than the level in the open side pressure check for the conditions in the table below 4 Close the shut off clamp before stopping the engine To test the crankcase vacuum with the Vacuum Pressure Gauge Kit 1 Remove the dipstick or oil fill plug cap 2 Install the adapter into the oil fill dipstick tube opening 3 Push the barbed fitting on the gauge solidly into the hole in the adapter 4 Start the engine and bring it up to operating speed 3200 3600 RPM 5 Check the reading on the gauge If the reading is to the left of 0 on the gauge vacuum or negative pressure is indicated If the reading is to the right of 0 on the gauge positive pressure is present Crankcase vacuum should be 4 10 inches of water If the reading is below specification or if pressure is present check the following table for possible causes and remedies 3 4 Section 3 Troubleshooting Possible Cause Solution 1 Disassemble breather clean part
158. e temporary adaptation can provide sufficient compensation Possible Causes 1 Oxygen Sensor Related a Sensor connector or wiring b Sensor contaminated or damaged c Exhaust leak d Poor ground path e Pin circuit wiring or connectors Pin 11 for 24 Pin MSE 1 0 Plastic Cased ECU Pin 20 for 32 Pin MSE 1 1 Plastic Cased ECU 2 TPS Sensor Related a Throttle plate position incorrect during Initialization procedure b TPS problem or malfunction 3 Engine Wiring Harness Related a Difference in voltage between sensed voltage pin circuit 2 and actual injector voltage circuit 45 45A b Problem in wiring harness c ECU to harness connection problem 4 Systems Related a Ignition spark plug plug wire ignition coil b Fuel fuel type quality injector fuel pressure fuel pump c Combustion air air cleaner dirty restricted intake leak throttle bores d Base engine problem rings valves e Exhaust system leak muffler flange oxygen sensor mounting boss etc f Fuel in the crankcase oil g Altitude h Blocked or restricted fuel return circuit to tank 5B 36 Section 5B EFI Fuel System Code 42 Source Engine Oil Temperature Sensor Explanation Not sending proper signal to ECU Expected Engine Response Engine will be hard to start because ECU can t determine correct fuel mixture Possible Causes 1 Temperature Sensor Related a Sensor wiring or connect
159. e while operating or just after stopping WARNING Hot Parts Engine components can get extremely hot from operation To prevent severe burns do not touch these areas while the engine is running or immediately after it is turned off Never operate the engine with heat shields or guards removed Accidental Starts can cause severe injury or death Disconnect and ground spark plug leads before servicing WARNING Accidental Starts Disabling engine Accidental starting can cause severe injury or death Before working on the engine or equipment disable the engine as follows 1 Disconnect the spark plug lead s 2 Disconnect negative battery cable from battery 1 2 Section 1 Safety and General Information Carbon Monoxide can cause severe nausea fainting or death Avoid inhaling exhaust fumes and never run the engine in a closed building or confined area WARNING WARNING Electrical Shock can cause injury Do not touch wires while engine is running CAUTION Uncoiling Spring can cause severe injury Wear safety goggles or face protection when servicing retractable starter WARNING Explosive Gas can cause fires and severe acid burns Charge battery only in a well ventilated area Keep sources of ignition away Lethal Exhaust Gases Engine exhaust gases contain poisonous carbon monoxide Carbon monoxide is odorless colorless and can cause death if inhaled Avoid inhaling exhaust fume
160. eal into the crankcase using a seal driver Make sure the oil seal is installed straight and true in the bore and the tool bottoms against the crankcase See Figure 11 2 11 2 Section 11 Reassembly Figure 11 2 Installing Oil Seal in Crankcase Install Governor Cross Shaft 1 Lubricate the governor cross shaft bearing surfaces in the crankcase with engine oil 2 Slide the small lower washer onto the governor cross shaft and install the cross shaft from the inside of the crankcase 3 6 mm Governor Shaft Install the plain washer and then insert the hitch pin into the smaller lower hole of the governor cross shaft See Figures 11 3 and 11 4 8 mm Governor Shaft Install the nylon washer onto the governor cross shaft then start the push on retaining ring Hold the cross shaft up in position place a 0 50 mm 0 020 in feeler gauge on top of the nylon washer and push the retaining ring down the shaft to secure Remove the feeler gauge which will have established the proper end play See Figures 11 5 and 11 6 Figure 11 4 Installing Governor Cross Shaft Hitch Pin 6 mm Shaft Figure 11 5 Installing 8 mm Governor Cross Shaft Figure 11 3 Installing 6 mm Governor Cross Shaft Figure 11 6 Setting Governor Cross Shaft End Play 8 mm Shaft 11 3 Section 11 Reassembly 11 Figure 11 7 Installing Crankshaft Install Connecting Rods with Pistons and Rings NOTE The cylinders are numbered on the crankca
161. ean the carburetor body jets vent ports seats etc using a good commercially available carburetor solvent Use clean dry compressed air to blow out the internal channels and ports Inspect and thoroughly check the carburetor for cracks wear or damage Inspect the fuel inlet seat for wear or damage Check the spring loaded choke plate to make sure it moves freely on the shaft 7 Clean the carburetor float bowl as required If it has an accelerator pump that is not being serviced at this time prevent the cleaning solvent from contacting the check valve and accelerator pump components 8 Install the main nozzle and the main jet into the tower of the carburetor body See Figure 5 20 Figure 5 20 Installing Main Nozzle and Main Jet 9 Install the slow jet and new plug into end of slow jet tube See Figures 5 21 and 5 22 5 16 Section 5 Fuel System and Governor Figure 5 22 Installing Plug into Slow Jet Tube 10 Attach the inlet needle to the metal tang of the float with the wire clip The formed 90 lip of the metal tang should point up with the needle valve hanging down See Figure 5 23 Figure 5 21 Installing Slow Jet Figure 5 25 Checking Float Height Figure 5 23 Float and Inlet Needle 11 Install the float and inlet needle down into the seat and carburetor body Insert the new pivot pin through the float hinge and secure with the new retaining screw See Figure 5 24 Figure 5 24 Installing Floa
162. eat the clamp and disconnect the accelerator pump hose if so equipped from the upper fitting Remove the four fuel bowl screws and carefully separate the fuel bowl from the carburetor Do not damage the O Ring s Transfer any remaining fuel into an approved container Save all parts See Figure 5 11 Figure 5 12 Removing Float and Inlet Needle 3 Clean the carburetor bowl and inlet seat areas as required before installation of new parts 4 Attach the inlet needle to the metal tang of the float with the wire clip The formed 90 lip of the metal tang should point up with the needle valve hanging down See Figure 5 13 Figure 5 11 Fuel Bowl Removed from Carburetor 2 Remove the float pin screw and lift out the old float pin and inlet needle See Figure 5 12 Discard all of the parts The seat for the inlet needle is not serviceable and should not be removed Figure 5 13 Float and Inlet Needle 5 Install the float and inlet needle down into the seat and carburetor body Insert the new pivot pin through the float hinge and secure with the new retaining screw See Figure 5 14 5 14 Section 5 Fuel System and Governor Figure 5 14 Installing Float Assembly 6 Hold the carburetor body so the float assembly hangs vertically and rests lightly against the fuel inlet needle The inlet needle should be fully seated but the center pin of the needle on retainer clip end should not be depressed Check the float heig
163. eather separator to the valve cover Position the hose in the cutout of the blower housing later models See Figure 11 84 Plastic Cased Pulse Fuel Pump Metal Cased Pulse Fuel Pump Install Fuel Pump WARNING Explosive Fuel Gasoline may be present in the carburetor and fuel system Gasoline is extremely flammable and its vapors can explode if ignited Keep sparks and other sources of ignition away from the engine 1 Install the fuel pump and lines as an assembly Connect the pulse line to the crankcase vacuum fitting See Figures 11 81 and 11 82 NOTE Fuel pumps may be made of metal or plastic If a new fuel pump is being installed make sure the orientation of the new pump is consistent with the removed pump Internal damage may occur if installed incorrectly Figure 11 82 Install Pulse Line 3 Connect the fuel lines See Figure 11 83 11 27 Section 11 Reassembly 11 Figure 11 85 Torquing Base and Spitback Cup Mounting Nuts Figure 11 84 Breather Hose and Separator Details 2 Position a new gasket and the air cleaner base on the studs while carefully pulling the loose end of the rubber breather hose through the base until properly seated collars sealed against each side of the base See Figure 11 85 3 Secure the air cleaner base and bracket or spit back cup with baffle using the hex flange nuts If a lower air cleaner bracket is used install the two M5 screws through the lower section of
164. ed into operation Even small amounts of these cleaners can quickly break down the lubricating properties of engine oil Typical Disassembly Sequence The following sequence is suggested for complete engine disassembly The sequence can be varied to accommodate options or special equipment 1 Disconnect spark plug leads 2 Shut off fuel supply 3 Drain oil from crankcase and remove oil filter 4 Remove oil cooler 5 Remove muffler 6 Remove air cleaner assembly 7 Remove control panel 8 Remove fuel pump 9 Remove throttle controls 10 Remove external governor controls 11 Remove carburetor 12 Remove electric starter motor 13 Remove outer baffles and blower housing 14 Remove Oil Sentry 15 Remove inner baffles and breather cover 16 Remove valve covers 17 Remove ignition modules 18 Remove intake manifold 19 Remove spark plugs 20 Remove cylinder heads and hydraulic lifters 21 Remove grass screen and fan 22 Remove flywheel 23 Remove stator and backing plates 24 Remove oil pan assembly 25 Remove camshaft 26 Remove governor cross shaft 27 Remove connecting rods with pistons and rings 28 Remove crankshaft 29 Remove flywheel end oil seal Disconnect Spark Plug Leads 1 Disconnect the leads from the spark plugs See Figure 9 1 NOTE Pull on boot only to prevent damage to spark plug lead Figure 9 1 Disconnect Spark Plug Leads Shut Off Fuel Supply Drain Oil
165. eds 700 RPM or lower the control pin protrudes above the exhaust cam lobe This pushes the exhaust valve off its seat during the first part of the compression stroke The reduced compression results in an effective compression ratio of about 2 1 during cranking After starting engine speed increases to over 700 RPM and centrifugal force overcomes the force of the flyweight spring The flyweight moves outward pulling the arm of the control pin so it pivots into the run position The control pin no longer has any effect on the exhaust valve and the engine operates at full power When the engine is stopped the spring returns the flyweight lever and control pin assembly to the compression release position ready for the next start Camshaft Inspection and Service Check the lobes of the camshaft for wear or damage See Section 1 for minimum lift specifications Inspect the cam gear for badly worn chipped or missing teeth Replacement of the camshaft will be necessary if any of these conditions exist Crankshaft Inspection and Service Inspect the gear teeth of the crankshaft If the teeth are badly worn chipped or some are missing replacement of the crankshaft will be necessary 10 2 Section 10 Inspection and Reconditioning The connecting rod journal can be ground one size under When grinding the crankshaft grinding stone deposits can get caught in the oil passages which could cause severe engine damage
166. edure NOTE The SAM must be at room temperature when tested Disconnect all of the SAM leads isolating it from the main wiring harness and the ignition module s Testing may be performed with the module mounted or loose The figures show the part removed from the engine for clarity Figure 8 10 1 Connect the tester to the SAM as follows Attach A The yellow tester lead to the long yellow module lead B The brown tester lead to the long brown module lead C The red tester lead to the red module lead D The green tester lead to the green module lead Caution Do not allow the alligator clip leads to touch each other Figure 8 11 8 12 Section 8 Electrical System and Components Figure 8 12 2 Check the SAM part number stamped on the side of the housing Verify that you have an analog SAM ASAM Part No 24 584 10 or lower not a digital SAM DSAM Part No 24 584 18 and higher Follow sub step a for testing an ASAM with this tester Digital SAM DSAM modules require Tester 25 761 40 S for proper testing a Depress the tester button and hold it down After approximately four seconds a numerical sequence should be displayed beginning with 1 or 2 and continuing to 8 or 9 followed by a letter P pass or F fail See Figures 8 11 and 8 12 Do not release the tester button until the test cycle completes and the display goes off If you get a sign instead of the numerical sequence and
167. eferring to Figure 8 35 grasp the spring retainer and push it toward the starter compressing the anti drift spring and exposing the retaining ring 4 Holding the spring retainer in the retracted position assemble the inner halves of the removal tool around the armature shaft with the retaining ring in the inner groove see Figure 8 36 Slide the collar over the inner halves to hold them in position Figure 8 37 Holding Tool and Turning Center Screw Clockwise to Remove Retaining Ring 6 Remove the drive components from the armature shaft paying attention to the sequence If the splines are dirty clean them with solvent 7 The splines should have a light film of lubricant Relubricate as necessary with Kohler starter drive lubricant see Section 2 Reinstall or replace the drive components assembling them in the reverse order they were removed 8 27 8 Section 8 Electrical System and Components Retaining Ring Installation 1 Position the retaining ring in the groove in one of the inner halves Assemble the other half over the top and slide on the outer collar 2 Be certain the drive components are installed in correct sequence onto the armature shaft 3 Slip the tool over the end of the armature shaft so the retaining ring inside is resting on the end of the shaft Hold the tool with one hand exerting slight pressure toward the starter Tap the top of the tool with a hammer until you feel the retaining
168. elay damaged Code 52 32 Pin MSE 1 1 Plastic Cased ECU only Source Injector 2 circuit open shorted to ground or shorted to battery Explanation Injector 2 is not functioning because the circuit is open shorted to ground or shorted to battery Expected Engine Response Engine will run very poorly with only one cylinder functioning Possible Causes 1 Injector Related a Injector coil shorted or opened 2 Engine Wiring Harness Related a Broken or shorted wire in harness ECU pin 15 to injector pin 2 ECU pin 28 to fuel pump relay pin 86 Note after key off then key on code 56 would be set also Fuel pump relay pin 87 to injector pin 1 b Opened main fuse F1 3 Fuel Pump Relay Related a Bad fuel pump relay Primary side functional but pin 30 to pin 87 remains open Primary side pin 85 to pin 86 is open or shorted during engine operation Note after key off then key on code 56 would be set also 4 ECU Related a Circuit controlling injector 2 damaged b Circuit controlling fuel pump relay damaged Code 55 32 Pin MSE 1 1 Plastic Cased ECU only Source MIL Diagnostic lamp circuit open shorted to ground or shorted to battery Explanation MIL is not functioning because the circuit is open shorted to ground or shorted to battery Expected Engine Response Engine will run normally if no other errors are present Possible Causes 1 MIL diagnostic lamp Related a
169. ely Start the engine and allow it to run for several minutes The MIL should remain off if the problem was corrected and the fault codes should not reappear codes 31 32 33 and 34 may require 10 15 minutes of running to reappear The following chart lists the fault codes what they correspond to and what the visual indications will be Following the chart is a list of the individual codes with an explanation of what triggers them what symptoms might be expected and the probable causes Diagnostic Code Summary Example of Diagnostic Display Long Pause 3 4 5 6 7 k n il B e d o C 2 D B O e d o C P elb a cilp p A n i P 2 3 o t 1 1 E S M ts y S U C E yln O m e n o it p ir c s e D e r ulia F r o n o itc e n n o C n i P 4 2 0 1 E S M d e s a C cits al P m e ts y S U C E n i P 2 3 1 1 E S M d e s a C cits al P m e ts y S U C E e t o N la n g i S M P R o N Y Y 1 2 5 3 3 0 P n o it a zin o r h c n y S f o s s o L Y Y 2 2 0 2 1 0 P elb is u alp m Ila n g i S S P T N N 2 2 2 2 2 1 0 P d n u o r G o t tiu c ri C tr o h S r o n e p O S P T Y Y 2 2 3 2 1 0 P y r e tt a B o t tiu c ri C tr o h S S P T Y
170. en screws until all items are installed to allow shifting for hole alignment 1 Pull the wire harness and spark plug leads out through the appropriate openings in the shrouding See Figures 11 57 and 11 58 Figure 11 57 Wires on Starter Side of Engine Figure 11 55 Installing Inner Baffles Figure 11 54 Installing Screws Locations 3 and 4 4 Install the inner baffles using the remaining two hex flange screws see Figures 11 55 and 11 56 and finger tighten Do not torque the screws at this time they will be tightened after the blower housing and outer baffles are installed Figure 11 56 Finger Tighten Two Remaining Cover Screws Figure 11 58 Wires on Oil Filter Side of Engine 2 Slide the blower housing into position over the front edge of the inner baffles See Figure 11 59 Start a few of the screws to hold it in place 11 17 Section 11 Reassembly 11 Figure 11 59 Installing Blower Housing 3 Position the outer baffles and secure using the four hex flange screws two long two short in the front mounting holes into cylinder head including any lifting strap or attached bracket s Install the two short screws in the upper mounting holes of the outer baffles into the backing plates See Figures 11 60 and 11 61 Use the short screw on the left side to mount the wire harness bracket Be sure any leads are routed out through the proper offsets or notches so they will not be pinched between the blo
171. eplace the battery remove the outer set of screws on the faceplate and carefully lift the panel from the body Unplug the connector and pull battery with mounting tape off the back of the tester Attach the connector to the new battery and mount the battery to the case with double backed tape Reinstall the faceplate and secure with the four screws 8 13 8 Section 8 Electrical System and Components Figure 8 14 Connected Tester Leads The test procedure for twin cylinder SAMs will vary slightly depending on whether the module is analog ASAM or digital DSAM 1 Check the SAM part number stamped on the end of the housing a If it is an ASAM 24 584 09 or 24 584 10 separate the short yellow and brown leads from the long ones Each set will be tested separately Connect the tester to the SAM as follows Yellow tester lead to long yellow module lead Brown tester lead to long brown module lead Red tester lead to the red module lead Black tester lead to the black or green module lead The remaining tester leads pink and brown with black band are not used for testing ASAMs b If it is a DSAM all except 24 584 09 or 24 584 10 connect the tester as follows Yellow tester lead to the long yellow module lead Brown tester lead to the long brown module lead Red tester lead to the red module lead Black tester lead to the green or black module ground lead with the eyelet
172. es Every 100 hours of operation more often under extremely dusty or dirty conditions replace the paper element See Figures 4 5 or 4 6 and follow these steps 1 Unhook the latches or loosen the cover retaining knob and remove the cover 2 Remove the wing nut element cover and air cleaner element 3 Remove the precleaner if so equipped from the paper element Service the precleaner as described in Precleaner Service 4 Do not wash the paper element or use pressurized air as this will damage the element Replace a dirty bent or damaged element with a genuine Kohler element Handle new elements carefully do not use if the sealing surfaces are bent or damaged 5 Check the rubber sleeve seal for any damage or deterioration Replace as necessary 6 Reinstall the paper element precleaner element cover and wing nut 7 Reinstall the air cleaner cover and secure with the two latches or the retaining knob Precleaner Element Precleaner Element 4 3 Section 4 Air Cleaner and Air Intake System 4 Wing Nut Air Cleaner Cover Plenum Cover Retaining Knob Air Cleaner Cover Std Element Cover Nut Element Cover Element Precleaner Air Cleaner Base Rubber Seal Stud Plenum air cleaner system does not use a precleaner Knob Knob Seal Air Cleaner Cover Element Cover Nut Rubber Seal Precleaner Element Cover Element Spitback Cup Gasket
173. es are listed below Use these to locate the causing factors Refer to the specific section s within this service manual for more detailed information Engine Cranks But Will Not Start 1 Empty fuel tank 2 Fuel shut off valve closed 3 Poor fuel dirt or water in the fuel system 4 Clogged fuel line 5 Spark plug lead s disconnected 6 Key switch or kill switch in off position 7 Faulty spark plugs 8 Faulty ignition module s 9 SMART SPARK malfunction applicable models 10 Carburetor solenoid malfunction 11 Diode in wiring harness failed in open circuit mode 12 Vacuum fuel pump malfunction or oil in vacuum hose 13 Vacuum hose to fuel pump leaking cracked 14 Battery connected backwards 15 Safety interlock system engaged Engine Starts But Does Not Keep Running 1 Restricted fuel tank cap vent 2 Poor fuel dirt or water in the fuel system 3 Faulty or misadjusted choke or throttle controls 4 Loose wires or connections that short the kill terminal of ignition module to ground 5 Faulty cylinder head gasket 6 Faulty carburetor 7 Vacuum fuel pump malfunction or oil in vacuum hose 8 Leaking cracked vacuum hose to fuel pump 9 Intake system leak 10 Diode in wiring harness failed in open circuit mode Engine Starts Hard 1 PTO drive is engaged 2 Dirt or water in the fuel system 3 Clogged fuel line 4 Loose or faulty wires or connections 5 Faulty or mi
174. eter lead to the engine ground location and repeat the output test The same voltage 0 2 v 1 0 v should be indicated a If the same voltage reading exists go on to Step 3 b If the voltage output is no longer correct a bad ground path exists between the sensor andthe engine ground Touch the black lead at various points backtracking from the engine ground back toward the sensor watching for a voltage change at each location If the correct voltage reading reappears at some point check for a problem rust corrosion loose joint or connection between that point and the previous checkpoint For example if the reading is too low at points on the crankcase but correct voltage is indicated when the black lead is touched to the skin of the muffler the flange joints at the exhaust ports become suspect 3 With the sensor still hot minimum of 400 C 752 F switch the meter to the Rx1K or Rx2K scale and check the resistance between the sensor lead and the sensor case It should be less than 2 0 K a If the resistance is less than 2 0 K go to Step 4 b If the resistance is greater than 2 0 K the oxygen sensor is bad replace it 4 Allow the sensor to cool less than 60 C 140 F and retest the resistance with the meter set on the Rx1M scale With sensor cool the resistance should be greater than 1 0 M a If the resistance is greater than 1 0 M
175. extending oil change intervals longer than recommended can cause engine damage NOTE Synthetic oils meeting the listed classifications may be used with oil changes performed at the recommended intervals However to allow piston rings to properly seat a new or rebuilt engine should be operated for at least 50 hours using standard petroleum based oil before switching to synthetic oil A logo or symbol on oil containers identifies the API service class and SAE viscosity grade See Figure 1 3 Use of synthetic oil having 5W 20 or 5W 30 rating is acceptable up to 40 F Synthetic oils will provide better starting in extreme cold below 10 F Figure 1 3 Oil Container Logo 1 5 Section 1 Safety and General Information 1 Perform these maintenance procedures more frequently under extremely dusty dirty conditions Only required for Denso starters Not necessary on Delco starters Have a Kohler Engine Service Dealer perform this service Cleanout Kits 25 755 20 S black or 25 755 21 S gold allow cooling areas to be cleaned without removing shrouds Storage If the engine will be out of service for two months or more use the following storage procedure 1 Clean the exterior surfaces of the engine On Electronic Fuel Injected EFI engines avoid spraying water at the wiring harness or any of the electrical components 2 Change the oil and oil filter while the engine is still warm from operation See
176. f the black leads from the tester to the pair of terminals on opposite end of adapter lead connections are not location specific 4 Connect the remaining black lead from tester to one of the black AC outside leads from rectifier regulator See Figure 8 31 Figure 8 31 5 Plug the tester into the proper AC outlet power supply for tester being used Turn on the power switch The POWER light should be illuminated and one of the four status lights may be on as well See Figure 8 26 This does not represent the condition of the part 6 Press the TEST button until a click is heard and then release See Figure 8 27 Momentarily one of the four lights will relight indicating the partial condition of the part a If the OK green light comes on disconnect the tester black lead attached to the AC lead reconnect it to the opposite side AC lead and repeat the test If the OK light green again comes on the part is good and may be used b If any other light is displayed in either of the tests the rectifier regulator is faulty and should not be used NOTE A flashing LOW light can also occur as a result of an inadequate ground lead connection Make certain connection location is clean and clamp is secure 4 Amp Unregulated Rectifiers 1 Connect the tester ground lead with spring clamp to the body of the rectifier being tested 2 Connect the red tester lead to the B
177. ffles See Figure 9 29 Short Screw Figure 9 26 Disconnecting Plug from Rectifier Regulator 2 The rectifier regulator does not have to be detached from the blower housing If the engine is equipped with SMART SPARK remove the mounting screws from the spark advance module SAM See Figure 9 27 The module will hang loose as part of the wiring harness 3 Remove the three each side hex flange screws securing the outer baffles Note the location of any lifting strap and the position of the two short screws one each side on bottom for reassembly See Figure 9 28 Remove Outer Baffles and Blower Housing 1 Disconnect the wire leads from the start switch on the blower housing if so equipped Disconnect the plug from the rectifier regulator Use the tip of the dipstick or a similar small flat tool to bend the locking tang then remove the B terminal from the center position in the plug See Figure 9 26 This will allow the blower housing to be removed without disturbing the wiring harness 9 9 Section 9 Disassembly 9 Figure 9 30 Removing Flywheel Screen 6 Remove the remaining hex flange screws securing the blower housing Note the one silver plated screw used for the rectifier regulator ground strap or lead Remove the blower housing See Figures 9 31 and 9 32 Figure 9 32 Removing Blower Housing Figure 9 31 Rectifier Regulator Ground Strap Ground Strap Silver Screw Figure 9 34 Removing I
178. formed stops of the choke shaft 11 Place a drop of the Loctite on the threads of each new screw Install the new choke plate to the flat side of the choke shaft and start the two screws The larger cutout must be on the right Close the choke and check the plate alignment within the carburetor throat then tighten the screws securely Do not overtighten 12 Check for proper operation and free movement of the parts Install the new cap Always use new gaskets when servicing or reinstalling carburetors Repair kits are available which include new gaskets and other components Service repair kits available for Keihin carburetors and affiliated components are Carburetor Repair Kit Float Kit Solenoid Assembly Kit Accelerator Pump Kit Choke Repair Kit High Altitude Kit 1525 3048 m 5 000 10 000 ft High Altitude Kit Over 3048 m 10 000 ft 9 Install the new return spring onto the new choke shaft so the upper leg of the spring is between the two formed stops on the end of the choke shaft See Figure 5 38 Note Make sure it stays in this location during the following step Carburetor Keihin BK Two Barrel Carburetor CV750 The carburetor used on CV750 engines is a Keihin two barrel side draft design with fixed main jets See Figure 5 39 A self relieving choke similar to that used on single venturi carburetors is also contained in the design The circuits within the carburetor function as described following
179. free for the life of the engine Other than periodically checking replacing the spark plugs no maintenance or timing adjustments are necessary or possible Mechanical systems do occasionally fail or break down however so the following troubleshooting information is provided to help you get to the root of a reported problem CAUTION High Energy Electric Spark The CD ignition systems produce a high energy electric spark but the spark must be discharged or damage to the system can result Do not crank or run an engine with a spark plug lead disconnected Always provide a path for the spark to discharge to ground Reported ignition problems are most often due to poor connections Before beginning the test procedure check all external wiring Be certain all ignition related wires are connected including the spark plug leads Be certain all terminal connections fit snugly Make sure the ignition switch is in the run position NOTE The CD ignition systems are sensitive to excessive load on the kill lead If a customer complains of hard starting low power or misfire under load it may be due to excessive draw on the kill circuit Perform the appropriate test procedure Test Procedure for Standard Fixed Timing CD Ignition System Isolate and verify the trouble is within the engine ignition system 1 Locate the plug connectors where the wiring harnesses from the engine and equipment are joined Separate the connectors and remove t
180. g method it should be 90 octane minimum Unleaded gasoline is recommended as it leaves less combustion chamber deposits and reduces harmful exhaust emissions Leaded gasoline is not recommended and must not be used on EFI engines or on other models where exhaust emissions are regulated Gasoline Alcohol blends Gasohol up to 10 ethyl alcohol 90 unleaded gasoline by volume is approved as a fuel for Kohler engines Other gasoline alcohol blends are not approved Gasoline Ether blends Methyl Tertiary Butyl Ether MTBE and unleaded gasoline blends up to a maximum of 15 MTBE by volume are approved as a fuel for Kohler engines Other gasoline ether blends are not approved 5 2 Section 5 Fuel System and Governor Fuel Filter Most engines are equipped with an in line filter Periodically inspect the filter and replace with a genuine Kohler filter every 200 operating hours Fuel Line In compliance with CARB Tier III Emission Regulations carbureted engines with a Family identification number beginning with 6 or greater See Figure 5 1 must use Low Permeation SAE 30 R7 rated fuel line certified to meet CARB requirements Standard fuel line may not be used Order replacement hose by part number through a Kohler Engine Service Dealer Figure 5 1 Family Number Location KOHLER CO KOHLER WISCONSIN USA EMISSION COMPLIANCE PERIOD EPA CARB CERTIFIED ON REFER TO OWNER S MANUAL FOR HP RATING SAFET
181. g 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 system 5B 39 Section 5B EFI Fuel System 5B Figure 5B 41 Operate for an appropriate period of time based upon original fault codes 5B 40 Section 5B EFI Fuel System Flow Chart Diagnostic Aids Diagnostic Aid 1 SYSTEM POWER MIL does not illuminate when key is turned on Possible causes 1 Battery 2 Main system fuse 3 MIL light bulb burned out 4 MIL electrical circuit problem 24 Pin MSE 1 0 Plastic Cased ECU Pin circuits 19 and 84 32 Pin MSE 1 1 Plastic Cased ECU Pin circuits 29 and 84 5 Ignition switch 6 Permanent ECU power circuit problem 24 Pin MSE 1 0 Plastic Cased ECU Pin circuit 1 32 Pin MSE 1 1 Plastic Cased ECU Pin circuit 1 7 Switched ECU power circuit problem 24 Pin MSE 1 0 Plastic Cased ECU Pin circuit 2 32 Pin MSE 1 1 Plastic Cased ECU Pin circuit 2 8 ECU grounds 9 ECU Diagnostic Aid 2 FAULT CODES Refer to detailed fault code listing before flow chart and servicing information for the respective components 1 Code 21 Engine Speed Synchronization 2 Code 22 Throttle Position Sensor TPS 3 Code 23 Engine Control Unit ECU 4 Code 31 O
182. ge screw Torque the screw to 4 0 N m 35 in lb See Figure 11 33 Valve Keepers Retainer Cap Spring Intake Valve Seal 11 11 Section 11 Reassembly 11 Figure 11 36 Installing Valves with Valve Spring Compressor Install Cylinder Heads NOTE Cylinder heads must be attached with the original type of mounting hardware using either hex flange screws or mounting studs with nuts and washers The heads are machined differently for studs than for screws so the fastening method cannot be altered unless the heads are being replaced Do not intermix the components 1 Check to make sure there are no nicks or burrs on the sealing surfaces of the cylinder head or the crankcase Heads secured with hex flange screws 2 Install a new cylinder head gasket with printing up NOTE Match the numbers embossed on the cylinder heads and crankcase See Figure 11 32 3 Install the cylinder head and start the four new hex flange screws NOTE When installing cylinder heads new screws should always be used Figure 11 37 Torquing Cylinder Head Fasteners 4 Torque the hex flange screws in two stages first to 22 6 N m 200 in lb then finally to 41 8 N m 370 in lb following the sequence in Figure 11 38 Figure 11 38 Cylinder Head Fastener Torque Sequence 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
183. generally unlikely due to the design of the injectors the high fuel pressure and the detergent additives in the gasoline Symptoms that could be caused by dirty clogged injectors include rough idle hesitation stumble during acceleration or triggering of fault codes related to fuel delivery Injector clogging is usually caused by a buildup of deposits on the director plate restricting the flow of fuel resulting in a poor spray pattern Some contributing factors 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 Figure 5B 19 Injector Inspection Points 1 Engine must be cool Depressurize fuel system through test valve in fuel rail 2 Disconnect spark plug leads from spark plugs 3 Remove the air cleaner outer cover inner wing nut element cover and air cleaner element precleaner Service air cleaner components as required 4 Remove the two screws securing the air cleaner base to the throttle body manifold Remove the air cleaner base to permit access to the injectors Check condition of air cleaner base gasket replace if necessary 5 Remove the flywheel screen if it overlaps the blower housing 6 If the engine has a radiator type oil cooler mo
184. ger two or three times to force the oil out of the feed hole in the side of the lifter Oil Pan Assembly Inspection Inspect the oil seal in the oil pan and remove it if it is worn or damaged Refer to Install Oil Seal in Oil Pan in Section 11 for new oil seal installation Inspect the main bearing surface for wear or damage refer to Section 1 Specifications Tolerances and Special Torque Values Replace the oil pan assembly if required Governor Gear Assembly Inspection Inspect the governor gear teeth Replace the gear if it is worn chipped or if any teeth are missing Inspect the governor weights They should move freely in the governor gear Center Compression Ring Piston Ring End Gap Identification Mark Dykem Stripe Piston Top Compression Ring Rails Expander Oil Control Ring Three piece 10 12 Section 10 Inspection and Reconditioning Figure 10 13 Removing Governor Gear 2 Remove the locking tab thrust washer located under the governor gear assembly 3 Carefully inspect the governor gear shaft and replace it only if it is damaged After removing the damaged shaft press or lightly tap the replacement shaft into the oil pan to the depth shown in Figure 10 14 Reassembly 1 Install the locking tab thrust washer on the governor gear shaft with the tab down 2 Position the regulating pin within the governor gear flyweight assembly and slide both onto gover
185. governor and throttle linkage If the governor throttle components are all intact but you think there may be a problem with the adjustment follow Procedure A to check the setting If the governor lever was loosened or removed go immediately to Procedure B to perform the initial adjustment A Checking the Initial Adjustment 1 Unsnap the plastic linkage bushing attaching the throttle linkage to the governor lever See Figure 5B 34 Unhook the damper spring from the lever separate the linkage from the bushing and remove the bushing from the lever Mark the hole position and unhook the governor spring from the governor lever Figure 5B 35 Throttle Details a On engines with a stop screw pivot the throttle shaft and plate into the Full Throttle position so the tang of the throttle shaft plate is against the end of the high speed stop screw See Figure 5B 35 Temporarily clamp in this position Idle Speed Screw Figure 5B 34 Throttle Linkage Governor Lever Connection 2 Check if the engine has a high speed throttle stop screw installed in the manifold casting boss See Figure 5B 35 High Speed Throttle Stop Screw Linkage Bushing Throttle Linkage Damper Spring 5B 24 Section 5B EFI Fuel System Figure 5B 37 Throttle Link in Center of Hole Figure 5B 36 Inserting Feeler Gauge Engines Without Stop Screw b On engines without a stop screw pivot the throttle shaft and plate assembly into th
186. h either a Nikki or Keihin one barrel fixed main jet carburetor Some applications use a fuel shut off solenoid installed in place of the fuel bowl retaining screw and also an accelerator pump All carburetors feature a self relieving choke like or similar to the one shown in the exploded view on page 5 12 These carburetors include three main circuits which function as described following CV750 engines use a Keihin BK two barrel carburetor on a matching intake manifold This carburetor with related servicing and adjustments is covered beginning on page 5 20 CV17 740 Engines Float Circuit The fuel level in the bowl is maintained by the float and fuel inlet needle The buoyant force of the float stops fuel flow when the engine is at rest When fuel is being consumed the float will drop and fuel pressure will push the inlet needle away from the seat allowing more fuel to enter the bowl When demand ceases the buoyant force of the float will again overcome the fuel pressure and stop the flow Figure 5 2 Pulse Pump Connections Performance Minimum fuel delivery rate must be 7 5 L hr 2 gal hr with a pressure at 0 3 psi and a fuel lift of 24 in A 1 3 L hr 0 34 gal hr fuel rate must be maintained at 5 Hz Replacing the Fuel Pump Replacement pumps are available through your source of supply To replace the pulse pump follow these steps Note orientation of pump before removing 1 Disconnect the fuel lines from the inlet
187. h of each brush The minimum length for each brush is 7 6 mm 0 300 in See Figure 8 56 Replace the brushes if they are worn undersize or their condition is questionable 8 35 8 Section 8 Electrical System and Components Figure 8 60 Service Brush Kit 5 Perform Steps 10 13 in the Starter Reassembly sequence Installation must be done after the armature drive lever and frame are installed if the starter has been disassembled Brush Replacement The brushes and springs are serviced as a set 4 Use Brush and Spring Kit Kohler Part No 25 221 01 S if replacement is necessary 1 Perform steps 1 5 in Starter Disassembly 2 Remove the two screws securing the brush holder assembly to the end cap plate Note the orientation for reassembly later See Figure 8 59 Discard the old brush holder assembly Figure 8 59 Removing Brush Holder 3 Clean the component parts as required 4 The new brushes and springs come preassembled in a brush holder with a protective sleeve that will also serve as an installation tool See Figure 8 60 Starter Service Clean the drive lever and armature shaft Apply Kohler electric starter drive lubricant see Section 2 Versilube G322L or Mobil Temp SHC 32 to the lever and shaft Clean and check the other starter parts for wear or damage as required Starter Reassembly 1 Apply drive lubricant see Section 2 to the armature shaft splines Install the drive pinio
188. haft position 84 BTDC for cylinder 1 This signal serves as a reference for the control of ignition timing by the ECU Synchronization of the inductive speed pickup and crankshaft position takes place during the first two revolutions each time the engine is started The sensor must be properly connected at all times If the sensor becomes disconnected for any reason the engine will quit running Service The engine speed sensor is a sealed non serviceable assembly If Fault Code diagnosis indicates a problem within this area test and correct as follows 1 Check the mounting and air gap of the sensor It must be 1 5 mm 0 25 mm 0 059 0 010 in 2 Inspect the wiring and connections for damage or problems 3 Make sure the engine has resistor type spark plugs 4 Disconnect the main harness connector from the ECU 5 Connect an ohmmeter between the 9 and 10 pin terminals See chart on page 5B 26 or 5B 29 according to ECU style A resistance value of 750 1000 at room temperature 20 C 68 F should be obtained If resistance is correct check the mounting air gap toothed ring gear damage run out etc and flywheel key 6 Disconnect the speed sensor connector from the wiring harness It is the connector with one heavy black lead see Figure 5B 4 Viewing the connector as shown dual aligning rails on top test resistance between the terminals indicated A reading of 750 1000
189. he white kill lead from the engine connector Rejoin the connectors and position or insulate the kill lead terminal so it cannot touch ground Try to start the engine to verify whether the reported problem is still present a If the problem is gone the electrical system on the unit is suspect Check the key switch wires connections safety interlocks etc b If the problem persists the condition is associated with the ignition or electrical system of the engine Leave the kill lead isolated until all testing is completed NOTE If the engine starts or runs during any of the testing you may need to ground the kill lead to shut it down Because you have interrupted the kill circuit it may not stop using the switch 2 Test for spark on both cylinders with Kohler ignition tester see Section 2 Disconnect one spark plug lead and connect it to the post terminal of the tester Connect the clip to a good ground not to the spark plug Crank the engine and observe the tester spark gap Repeat the procedure on the other cylinder Remember to reconnect the first spark plug lead 8 8 Section 8 Electrical System and Components a If one side is not firing check all wiring connections and terminations on that side If wiring is okay replace ignition module and retest for spark b If the tester shows spark but the engine misses or won t run on that cylinder try a new spark plug c If neither side is firing
190. he camshaft See Figure 11 13 4 Slide the camshaft into the bearing surface of the crankcase positioning the timing mark of camshaft gear at the 6 o clock position Make sure the camshaft gear and crankshaft gear mesh with both timing marks aligned See Figure 11 13 Figure 11 10 Connecting Rod Bolts Torque these to 22 7 N m 200 in lb 8 mm Straight Shank Torque these to 14 7 N m 130 in lb 8 mm Step Down Torque these to 11 3 N m 100 in lb 6 mm Straight Shank Governor Cross Shaft Timing Marks 11 5 Section 11 Reassembly 11 Figure 11 14 Checking Camshaft End Play 3 Apply pressure on the camshaft end play checking tool pushing camshaft toward crankshaft Use a feeler gauge to measure the camshaft end play between the shim spacer and the checking tool Camshaft end play should be 0 076 0 127 mm 0 003 0 005 in 4 If the camshaft end play is not within the specified range remove the checking tool and replace the shim as necessary Several color coded shims are available White 0 69215 0 73025 mm 0 02725 0 02875 in Blue 0 74295 0 78105 mm 0 02925 0 03075 in Red 0 79375 0 83185 mm 0 03125 0 03275 in Yellow 0 84455 0 88265 mm 0 03325 0 03475 in Green 0 89535 0 99345 mm 0 03525 0 03675 in Gray 0 94615 0 98425 mm 0 03725 0 03875 in Black 0 99695 1 03505 mm 0 03925 0 04075 in 5 Reinstall the end play checking tool and recheck the end play Oil Pump As
191. he engine reconnect the fuel line control linkages and air intake components Retest operation 5 11 Section 5 Fuel System and Governor 5 Disassembly Use the carburetor repair kit and the float repair kit if float components are to be replaced Refer to Figure 5 10 for parts identification The Kohler part number and the Nikki lot number are stamped on the choke side flange on top of the carburetor body Refer to the parts manual for the carburetor involved to ensure the correct repair kits and replacement parts are used Disassemble carburetor as follows after removal from the engine See Figure 5 10 1 Remove the fuel bowl retaining screw or solenoid assembly then remove the bowl and bowl gasket On solenoid equipped carburetors the main jet is mounted in the tip of the solenoid pin Be careful that it does not get damaged while the solenoid is separated from the carburetor 2 Pull the float hinge pin and remove the float with the inlet needle attached 3 Remove the vent plug from the column on fuel solenoid equipped carburetors 4 Remove the screws holding the throttle plate to the throttle shaft pull the throttle shaft from the carburetor body 5 Remove the screws securing the choke plate to the choke shaft assembly and pull the choke shaft assembly out of the carburetor body Disassemble the self relieving parts from shaft as needed 6 Remove the three screws holding the passage cover to the body
192. he proper AC outlet power supply for tester being used Turn on the power switch See Figure 8 26 The POWER light should be illuminated and one of the four status lights may be on as well This does not represent the condition of the part Figure 8 27 a If the OK green light comes on and stays steady the part is good and may be used b If any other light is displayed the rectifier regulator is faulty and should not be used NOTE A flashing LOW light can also occur as a result of an inadequate ground lead connection Make certain connection location is clean and clamp is secure Figure 8 26 4 Press the TEST button until a click is heard and then release See Figure 8 27 Momentarily one of the four status lights will illuminate indicating the condition of the part 20 25 Amp Rectifier Regulators 1 Connect the single lead adapter in between the B center terminal of the rectifier regulator being tested and the squared single end of the tandem adapter lead See Figure 8 28 Figure 8 28 2 Connect the tester ground lead with spring clamp to the body of the rectifier regulator 3 Connect the red lead and one of the black leads to the pair of terminals on the open end of the tandem adapter lead connections are not location specific 4 Connect the remaining black lead from the tester to one of the outer AC terminals on the rectifier regulator See Figure 8 29
193. he thrust washer from inside the commutator end See Figure 8 49 Figure 8 49 Removing Commutator End Plate Assembly 6 Remove the frame from the armature and drive end cap See Figure 8 50 Figure 8 52 Armature and Lever Removed 10 Push the stop collar down to expose the retaining ring See Figure 8 53 Figure 8 50 Starter Frame Removed 7 Remove the drive lever pivot bushing and backing plate from the end cap See Figure 8 51 Figure 8 51 8 Take out the drive lever and pull the armature out of the drive end cap See Figure 8 52 9 Remove the thrust washer from the armature shaft See Figure 8 52 8 33 8 Section 8 Electrical System and Components Figure 8 54 Removing Retaining Ring 12 Remove the drive pinion assembly from the armature 13 Clean the parts as required NOTE Do not soak the armature or use solvent when cleaning Wipe clean using a soft cloth or use compressed air Figure 8 53 Retaining Ring Detail 11 Remove the retainer from the armature shaft Save the stop collar NOTE Do not reuse the old retainer Lever Solenoid CE Frame Bolt Ring Stop Drive Armature Washer Screw Plunger Spring Plate Collar Tube Screw Plug Frame amp Field Brush Holder Nut Figure 8 55 Delco Remy Starter 8 34 Section 8 Electrical System and Components Figure 8 56 Checking Brushes Armature 1 Clean and inspect the commuta
194. hot parts or sparks from ignition Do not start the engine near spilled fuel Never use gasoline as a cleaning agent Fuel System Components The typical carbureted fuel system and related components include the following Fuel Tank Fuel Lines In line Fuel Filter Fuel Pump Carburetor Operation The fuel from the tank is moved through the in line filter and fuel lines by the fuel pump On engines not equipped with a fuel pump the fuel tank outlet is located above the carburetor inlet allowing gravity to feed fuel to the carburetor Fuel then enters the carburetor float bowl and is drawn into the carburetor body There the fuel is mixed with air This fuel air mixture is then burned in the engine combustion chamber Fuel Recommendations General Recommendations Purchase gasoline in small quantities and store in clean approved containers A container with a capacity of 2 gallons or less with a pouring spout is recommended Such a container is easier to handle and helps eliminate spillage during refueling Do not use gasoline left over from the previous season to minimize gum deposits in your fuel system and to ensure easy starting Do not add oil to the gasoline Do not overfill the fuel tank Leave room for the fuel to expand Fuel Type For best results use only clean fresh unleaded gasoline with a pump sticker octane rating of 87 or higher In countries using the Research fuel ratin
195. ht adjustment NOTE The inlet needle center pin is spring loaded Make sure the float assembly rests against the fuel inlet needle without depressing the center pin 7 The correct float height adjustment is 12 0 mm 0 472 in measured from the float bottom to the body of the carburetor See Figure 5 15 Adjust the float height by carefully bending the metal tang of the float 8 When the proper float height is obtained carefully reinstall the fuel bowl with the O Ring s in place onto the carburetor Secure with the four original screws Torque the screws to 2 5 0 3 N m 23 2 6 in lb Reattach the accelerator pump hose if so equipped and secure with the clip See Figure 5 16 Figure 5 15 Checking Float Height NOTE Be sure to measure from the casting surface not the rubber gasket if still attached Figure 5 16 Installing Fuel Bowl Disassembly Overhaul 1 Clean the exterior surfaces of dirt or foreign material before disassembling the carburetor Unseat the clamp and disconnect the accelerator pump hose if so equipped from the upper fitting Remove the four fuel bowl screws and separate the fuel bowl from the carburetor Transfer any remaining fuel into an approved container Remove and discard the old O Ring s See Figure 5 17 Figure 5 17 Fuel Bowl Removed from Carburetor NOTE Further disassembly of fuel bowl is not necessary unless the Accelerator Pump Kit 24 757 47 S or Fuel Solenoid
196. ic Fuel Injection EFI Fuel System Contents Page s Description Initial Starting Priming Procedure 5B 2 Fuel Recommendations 5B 2 5B 3 EFI Fuel System Components 5B 3 Operation 5B 3 Important Service Notes 5B 4 Electrical Components Electronic Control Unit ECU 5B 4 5B 5 Engine Speed Sensor 5B 5 5B 6 Throttle Position Sensor TPS and Initialization Procedures 5B 6 5B 9 Engine Oil Temperature Sensor
197. ication System 6 Section 6 Lubrication System General This engine uses a full pressure lubrication system delivering oil under pressure to the crankshaft camshaft and connecting rod bearing surfaces In addition to lubricating the bearing surfaces the lubrication system supplies oil to the hydraulic valve lifters A high efficiency gerotor pump is located in the oil pan The oil pump maintains high oil flow and oil pressure even at low speeds and high operating temperatures A pressure relief valve in the oil pan limits the maximum pressure of the system Service The oil pan must be removed to service the oil pump or oil pickup Refer to the appropriate procedures in Sections 9 and 10 Oil Recommendations Using the proper type and weight of oil in the crankcase is extremely important so is checking oil daily and changing the oil and filter regularly Use high quality detergent oil of API American Petroleum Institute service class SG SH SJ or higher Select the viscosity based on the air temperature at the time of operation as shown in the following table Figure 6 1 Oil Container Logo The top position of the symbol shows service class such as API SERVICE CLASS SJ The symbol may show additional categories such as SH SG CC or CD The center portion shows the viscosity grade such as SAE 10W 30 If the bottom portion shows Energy Conserving it means that oil is intended to improve fuel economy in pa
198. ice the carburetor NOTE The actual low idle speed depends on the application Refer to the equipment manufacturer s recommendations The low idle speed for basic engines is 1200 RPM To ensure best results when setting the low idle fuel needle the low idle speed should be 1200 RPM 75 RPM Low Idle Fuel Adjustment NOTE Engines will have fixed low idle or limiter caps on the two idle fuel adjusting needles Step 3 can only be performed within the limits allowed by the cap Do not attempt to remove the limiter caps 1 Start the engine and run at half throttle for 5 to 10 minutes to warm up The engine must be warm before doing steps 2 3 and 4 2 Place the throttle control into the idle or slow position Adjust the low idle speed to 1200 RPM Follow the Adjusting the Low Idle Speed RPM procedure 3 Low Idle Fuel Needle s Setting Place the throttle into the idle or slow position a Turn one of the low idle fuel adjusting needles out counterclockwise from the preliminary setting until the engine speed decreases rich Note the position of the needle Now turn the adjusting needle in clockwise The engine speed may increase then it will decrease as the needle is turned in lean Note the position of the needle Set the adjusting needle midway between the rich and lean settings See Figure 5 40 b Repeat the procedure on the other low idle adjustment needle 4 Recheck adj
199. ing the idle speed If speed adjustments are required proceed as follows 1 Make any necessary speed or control adjustments following the appropriate instructions covered in this section 2 Move the throttle control to the idle position Hold the governor lever away from the carburetor or hold the throttle lever so it is tight against the idle speed adjusting screw to negate the governor activation See Figure 5 8 Check the speed with a tachometer and adjust it to 1500 RPM 3 Release the governor lever and allow the engine to return to the governed idle speed Check it with a tachometer against the equipment manufacturers recommended idle speed Governed Idle Speed RPM is typically 300 RPM approximate higher than the low idle speed If adjustment is necessary bend the adjusting tab on the speed control assembly to set See Figure 5 7 Low Idle Fuel Adjustment Some Models Low Idle Speed RPM Adjustment NOTE The tip of the idle fuel adjusting needle is tapered to critical dimensions Damage to the needle and the seat in the carburetor body will result if the needle is forced 5 10 Section 5 Fuel System and Governor 16 5 mm 0 65 in Turn Carburetor Upside Down Figure 5 7 Governed Idle Spring Location Figure 5 8 Holding Throttle Lever Against Idle Stop Screw One Barrel Carburetor Carburetor Servicing CV17 740 Nikki Carburetors Float Replacement If symptoms described in the carbureto
200. ion 2 Engine Wiring Harness Related 24 Pin MSE 1 0 Plastic Cased ECU a Pin circuits 4 6 and or 4A damaged wires connectors or routed near noisy signal coils alternator etc b ECU to harness connection problem 2 Engine Wiring Harness Related 32 Pin MSE 1 1 Plastic Cased ECU a Pin circuits 4 6 and or 4A damaged wires connectors or routed near noisy signal coils alternator etc b ECU to harness connection problem 3 System Related a Engine is operating above the 176 C 350 F temperature sensor limit Code 43 and 44 32 Pin MSE 1 1 Plastic Cased ECU only Source TPS Auto Learn initialization function failed throttle angle out of learning range Explanation While performing the TPS Auto Learn function the measured throttle angle was not within acceptable limits Expected Engine Response MIL illuminated Engine will continue to run but not properly Upon restart TPS Auto Learn function will run again unless voltage to ECU disconnected to clear memory Possible Causes 1 TPS Related a TPS rotated on throttle shaft assembly out of allowable range b TPS bad 2 Engine Wiring Harness Related a Broken or shorted wire in harness ECU pin 18 to TPS pin 1 ECU pin 4 to TPS pin 2 ECU pin 8 to TPS pin 3 3 Throttle Body Related a Throttle shaft inside TPS worn broken or damaged b Throttle plate loose or misaligned c Throttle plate bent or damaged
201. is gone the electrical system on the unit is suspect Check the key switch wires connections safety interlocks etc b If the problem persists the condition is associated with the ignition or electrical system of the engine Leave the kill lead isolated until all testing is completed NOTE If the engine starts or runs during any of the testing you may need to ground the kill lead to shut it down Because you have interrupted the kill circuit it may not stop using the switch Test 2 Test for spark 1 With the engine stopped disconnect one spark plug lead Connect the spark plug lead to post terminal of spark tester see Section 2 and attach tester clip to a good engine ground NOTE If two testers are available testing can be performed simultaneously for both cylinders However if only one tester is available two individual tests must be performed The side not being tested must have the spark plug lead connected or grounded Do not crank the engine or perform tests with one spark plug lead disconnected and not grounded or permanent system damage may occur 2 Crank the engine over establishing a minimum of 550 600 RPM and observe tester s for spark 3 On a twin cylinder engine repeat the spark test on the opposite cylinder if cylinders are being tested individually a If both cylinders have good spark but the engine runs poorly install new spark plugs gapped at 0 76 mm 0 030 in and retest engine
202. it rotates the flywheel and cranks the engine When the engine starts and the start switch is released the starter solenoid is deactivated the drive lever moves back and the drive pinion moves out of mesh with the ring gear into the retracted position Starter Assembly Armature Nut Drive Lever Dust Cover Solenoid Nut Drive Pinion Drive End Cap Frame Wire Brushes Brush Holder Brush Spring Insulator Commutator End Cap Thru Bolt Front Stop Collar Retainer Rear Stop Collar Figure 8 43 Nippondenso Solenoid Shift Starter 8 30 Section 8 Electrical System and Components Starter Disassembly 1 Disconnect the lead wire from the solenoid 2 Remove the hex nuts securing the solenoid and remove the solenoid from the starter assembly 3 Remove the two thru bolts 4 Remove the commutator end cap 5 Remove the insulator and the brush springs from the brush spring holder 6 Remove the armature from the frame 7 Remove the drive lever and the armature from the drive end cap NOTE When removing the lever and the armature be careful not to lose the thrust washer 8 The stop collar consists of two similar pieces held in place by being snapped over a retainer The retainer is held in place by a groove in the armature shaft To remove the stop collar the two pieces must be pried off the retainer 9 When the stop collars are removed the retainer can be removed from
203. k that the return line from the regulator to the tank is not kinked or blocked If the return line is good replace the regulator see Regulator Service on page 5B 20 b If the pressure is too low install in line T between the pump and the regulator and retest the pressure at that point If it is too low there also replace the fuel pump 3 If the pump did not activate step 2 disconnect the plug from the fuel pump Connect a DC voltmeter across the terminals in the plug turn on the key switch and observe if a minimum of 7 volts is present If voltage is between 7 and 14 turn key switch off and connect an ohmmeter between the terminals on the pump to check for continuity a If there was no continuity between the pump terminals replace the fuel pump Figure 5B 24 External Fuel Pressure Regulators Figure 5B 25 Internal Fuel Pressure Regulators b If the voltage was below 7 test the wiring harness and relay as covered in the Electrical Relay section 4 If voltage at the plug was good and there was continuity across the pump terminals reconnect the plug to the pump making sure you have a good connection Turn on the key switch and listen for the pump to activate a If the pump starts repeat steps 1 and 2 to verify correct pressure b If the pump still does not operate replace it Fuel Pressure Regulator 5B 20 Section 5B EFI Fuel System Figure 5B 26 Fuel Press
204. kup and Relief Valve Original Style Figure 10 17 Oil Pump Plastic Oil Pickup and One Piece Relief Valve Later Style Inspection Inspect the oil pump housing gear and rotors for nicks burrs wear or any visible damage If any parts are worn or damaged replace the oil pump Inspect the oil pressure relief valve piston It should be free of nicks or burrs Check the spring for wear or distortion The free length of the spring should be approximately 47 4 mm 1 8 in Replace the spring if it is distorted or worn See Figure 10 18 Figure 10 18 Oil Pressure Relief Valve Piston and Spring Reassembly 1 Install the pressure relief valve piston and spring 2 Install the oil pickup to the oil pump body Lubricate the O Ring with oil and make sure it remains in the groove as the pickup is being installed 3 Install the rotor 4 Install the oil pump body to the oil pan and secure with the two hex flange screws Torque the hex flange screws as follows a Install fastener into location No 1 and lightly tighten to position pump b Install fastener into location No 2 and fully torque to the recommended value c Torque fastener in location No 1 to the recommended value Piston Spring Roll Pin First Time Installation 10 7 N m 95 in lb All Reinstallations 6 7 N m 60 in lb Oil Pump Torque Sequence 10 14 Section 10 Inspection and Reconditioning 5 After torquing rotate the ge
205. l the drain plug Torque to 13 6 N m 10 ft lb 4 Fill the engine with the proper oil to the FULL mark on the dipstick Always check the oil level with the dipstick before adding more oil 5 Reinstall the oil fill cap dipstick Changing Oil Filter Replace the oil filter at least every other oil change every 200 hours of operation Always use a genuine Kohler oil filter Change the filter as follows See Figures 6 4 or 6 5 1 An oil drain plug is located on either side of the oil sump one is next to the oil filter the other is next to the starter Clean the areas around the most accessible drain plug the oil filter and the oil fill cap dipstick 2 Remove the selected drain plug and the oil fill cap dipstick 3 Allow the oil to drain and then reinstall the drain plug Torque to 13 6 N m 10 ft lb 4 Remove the old filter and wipe off the filter adapter with a clean cloth 5 Place a new replacement filter in a shallow pan with the open end up Pour new oil of the proper type in through the threaded center hole Stop pouring when the oil reaches the bottom of the threads Allow a minute or two for the oil to be absorbed by the filter material 6 Apply a thin film of clean oil to the rubber gasket on the new oil filter 7 Install the new oil filter to the filter adapter Hand tighten the filter clockwise until the rubber gasket contacts the adapter then tighten the filter an additio
206. l the new idle speed RPM adjustment screw and spring onto the carburetor Thread in until 3 or 4 threads are exposed as an initial adjustment See Figure 5 55 Nozzle End with Two Shoulders Out Down Main Jets Figure 5 55 Installing Idle Speed Adjusting Screw and Spring 12 Attach the inlet needle to the plastic tang of the float with the wire clip The formed 90 lip should point up with the needle valve hanging down See Figure 5 56 5 27 Section 5 Fuel System and Governor 5 Figure 5 58 Checking Float Height NOTE Be sure to measure from the casting surface not the rubber gasket if still attached 16 When the proper float height is obtained carefully reinstall the fuel bowl using new O Rings onto the carburetor Secure with the four original screws Torque the screws to 2 5 0 3 N m 23 2 6 in lb See Figure 5 59 Figure 5 60 Choke Details 5 Use a screw extractor easy out and remove the original choke shaft bushing with the old choke lever from the carburetor housing Save the bushing to use as a driver for installing the new bushing Discard the old lever 6 Clean the I D of both choke shaft bores as required 7 Insert the new bushing through the new choke lever from the outside and start the bushing in the outer shaft bore Position the choke lever so the protruding boss on the carburetor housing is between the two stops formed in the choke lever See Figure 5 61 Figu
207. lange screws in each cover and finger tighten 5 Torque the valve cover fasteners to the proper specification using the sequence shown in Figure 11 66 unless the screws also attach the heavy duty air cleaner main support bracket or other components Installation and torquing of the screws will be performed after these parts are installed Figure 11 66 Valve Cover Fastener Torque Sequence Install Carburetor WARNING Explosive Fuel Gasoline may be present in the carburetor and fuel system Gasoline is extremely flammable and its vapors can explode if ignited Keep sparks and other sources of ignition away from the engine 1 Install a new carburetor gasket Make sure all holes align and are open 2 Install the carburetor throttle linkage choke linkage and governor lever as an assembly See Figures 11 67 and 11 68 If a plastic intake manifold is used and or the carburetor is equipped with a fuel solenoid reconnect the ground and main leads See Figure 11 69 1 2 3 4 Gasket RTV style cover 3 4 N m 30 in lb Black O Ring style cover w shoulder screws 5 6 N m 50 in lb w screws and spacers 9 9 N m 88 in lb Yellow or Brown O Ring style cover w integral spacers 6 2 N m 55 in lb 11 20 Section 11 Reassembly Figure 11 70 Install Governor Lever to Shaft 2 Make sure the throttle linkage is connec
208. ld cranking requirement depends on engine size application and starting temperatures The cranking requirements increase as temperatures decrease and battery capacity shrinks Refer also to the operating instructions for the piece of equipment for specific battery requirements Battery Size Recommendations If the battery charge is not sufficient to turn over the engine recharge the battery Battery Maintenance Regular maintenance is necessary to prolong battery life WARNING Explosive Gas Batteries produce explosive hydrogen gas while being charged To prevent a fire or explosion charge batteries only in well ventilated areas Keep sources of ignition away from the battery at all times Keep batteries out of the reach of children Remove all jewelry when servicing batteries Before disconnecting the negative ground cable make sure all switches are OFF If ON a spark will occur at the ground cable terminal which could cause an explosion if hydrogen gas or gasoline vapors are present 1 Regularly check the level of electrolyte Add distilled water as necessary to maintain the recommended level NOTE Do not overfill the battery Poor performance or early failure due to loss of electrolyte will result Figure 8 2 Battery Voltage Test DC Voltmeter Battery Temperature Battery Required Above 32 F 0 C 200 cca minimum 0 F to 32 F 18 C to 0 C 250 cca minimum 5 F to 0 F 21 C to 18 C
209. le control bracket 3 Disconnect the throttle control bracket from the cylinder head See Figure 9 14 4 Remove the panel from the blower housing See Figure 9 15 4 Remove the two upper screws securing the air cleaner mounting bracket to the blower housing and remove the air cleaner assembly See Figures 9 12 and 9 13 Figure 9 10 Removing Breather Hose Hex Nuts and Adapter Elbow Two Barrel Model Pictured 2 Pull the adapter elbow and gasket off the mounting studs 3 Remove the four screws inner two valve cover screws on each side securing the air cleaner main support bracket Do not lose any of the mounting hardware Two Barrel Carburetor Models only Unhook the choke return spring from the bottom of the air cleaner mounting bracket See Figure 9 11 Hex Nuts Adapter Elbow Breather Hose Choke Return Spring Figure 9 12 Removing Upper Mounting Screws Upper Mounting Screws Main Bracket Mounting Screws 9 5 Section 9 Disassembly 9 Figure 9 14 Removing Throttle Control Bracket Figure 9 15 Removing Control Panel Remove Fuel Pump WARNING Explosive Fuel Gasoline may be present in the carburetor and fuel system Gasoline is extremely flammable and its vapors can explode if ignited Keep sparks open flames and other sources of ignition away from the engine 1 Disconnect the fuel lines at the carburetor and at the in line fuel filter Figure 9 17 Pulse Fuel Pump Details
210. leakage and also insulate it from heat and vibration A special clip connects each injector to the fuel rail and holds it in place The O Rings should be replaced anytime the injector is removed When the key switch is on and the relay is closed the fuel rail is pressurized and voltage is present at the injector At the proper instant the ECU completes the ground circuit energizing the injector The valve needle in the injector is opened electromagnetically and the pressure in the fuel rail forces fuel down through the inside The director plate at the tip of the injector see inset contains a series of calibrated openings which directs the fuel into the manifold in a cone shaped spray pattern Figure 5B 16 Fuel Injector Details The injector is opened and closed once for each crankshaft revolution however only one half the total amount of fuel needed for one firing is injected during each opening The amount of fuel injected is controlled by the ECU and determined by the length of time the valve needle is held open also referred to as the injection duration or pulse width It may vary in length from 1 5 8 milliseconds depending on the speed and load requirements of the engine Service Injector problems typically fall into three general categories electrical dirty clogged or leakage An electrical problem usually causes one or both of the injectors to stop functioning Several methods may be used to check if
211. ll the hex flange nuts to the exhaust studs Torque hex flange nuts to 24 4 N m 216 in lb Install Oil Cooler If so equipped the oil cooler can now be installed to the engine Two different styles are used see Section 6 1 Depending on style used reverse the removal procedure from Section 9 2 Secure the cooler or adapter to the oil pan with the oil filter nipple Torque the oil filter nipple to 27 N m 20 ft lb Install Oil Filter and Fill Crankcase with Oil 1 Prefill a new oil filter following the instructions in Section 6 2 Apply a thin film of clean oil to the rubber gasket on the oil filter and thread the filter onto the adapter nipple See Figure 11 91 3 Hand tighten the filter until the rubber gasket contacts the adapter then tighten the filter an additional 3 4 1 turn Figure 11 91 Installing and Tightening Oil Filter 4 Install the oil drain plug s See Figure 11 92 Torque plug s to 13 6 N m 10 ft lb Figure 11 88 Installing Upper Mounting Screws 5 Torque the valve cover mounting bracket screws to the proper specification and torque sequence listed under Install Valve Covers on page 11 19 11 29 Section 11 Reassembly 11 Figure 11 92 Install Oil Drain Plug s Prepare the Engine for Operation The engine is now completely reassembled Before starting or operating the engine be sure to do the following 1 Make sure all hardware is tightened securely 2 Make
212. low from the line check the fuel tank vent fuel pickup screen in line filter shut off valve and fuel line Correct any observed problem and reconnect the line 4 Check the operation of fuel pump a Remove the fuel line from the inlet fitting of carburetor b Crank the engine several times and observe flow 4 If fuel does flow from the line check for faulty carburetor Refer to the Carburetor portions of this section If fuel does not flow from the line check for a clogged fuel line If the fuel line is unobstructed check for overfilled crankcase and or oil in pulse line If none of the checks reveal the cause of the problem replace the pump Fuel System Tests When the engine starts hard or turns over but will not start it is possible that the problem is in the fuel system To find out if the fuel system is causing the problem perform the following tests 5 4 Section 5 Fuel System and Governor 3 Remove the pulse line that connects the pump to the crankcase 4 Install a new pump using the hex flange screws NOTE Make sure the orientation of the new pump is consistent with the removed pump Internal damage may occur if installed incorrectly 5 Connect the pulse line between the pump and crankcase 6 Torque the hex flange screws to 2 3 N m 20 in lb 7 Connect the fuel lines to the inlet and outlet fittings Carburetor General CV17 740 engines in this series are equipped wit
213. lso be drained prior to bowl removal by loosening removal of the bowl drain screw See Figure 5 43 Hold Throttle Lever Against Screw 5 23 Section 5 Fuel System and Governor 5 Figure 5 45 Float and Inlet Needle Details 6 Install the float and inlet needle down into the seat and carburetor body Install the new pivot pin through the float hinge and secure with the new retaining screw See Figure 5 46 Figure 5 44 Removing Float and Inlet Needle 4 Clean the carburetor bowl and inlet seat areas as required before installing the new parts 5 Attach the inlet needle to the plastic tang of the float with the wire clip The formed 90 lip should point up with the needle valve hanging down See Figure 5 45 Figure 5 43 Fuel Bowl Removed From Carburetor 3 Remove the float pin screw and lift out the old float pin and inlet needle See Figure 5 44 Discard all of the parts The seat for the inlet needle is not serviceable and should not be removed Fuel Bowl Bowl Drain Screw Figure 5 46 Installing Float Assembly 7 Hold the carburetor body so the float assembly hangs vertically and rests lightly against the fuel inlet needle The inlet needle should be fully seated but the center pin of the needle on retainer clip end should not be depressed Check the float height adjustment NOTE The inlet needle center pin is spring loaded Make sure the float rests against the fuel inlet needle without de
214. lywheel so the magnet is centered under the module 2 1 4 2 1 3 24 584 03 or 24 584 11 1 11 16 in High 24 584 15 S or 24 584 36 S 2 1 16 in High t s e T l a ti g i D e s U r e t e m m h O 3 0 4 8 5 4 2 1 1 4 8 5 4 2 H n i 6 1 1 1 1 S 5 1 4 8 5 4 2 H n i 6 1 1 2 S 6 3 4 8 5 4 2 H n i 6 1 1 2 o N m o r F 4 o t 1 o t 5 4 9 s m h o 5 7 1 1 o t 0 9 8 s m h o 5 7 1 1 o t 0 9 5 s m h o 6 1 6 o N m o r F 4 o t 2 o t 9 4 1 s m h o 6 6 1 o t 9 1 1 s m h o 6 3 1 o t 3 8 1 s m h o 8 0 2 o N m o r F 4 o t 3 o t 0 5 7 3 s m h o 0 0 0 7 o t 0 0 6 5 s m h o 0 0 0 9 o t 0 0 0 8 s m h o 0 0 0 0 4 8 11 8 Section 8 Electrical System and Components a If correct voltage is not measured connect black voltmeter lead directly to the negative post of the battery and test voltage again in both key positions If correct voltage is now indicated check the ground circuit connections If the ground screw bolt or any other fasteners in the ground circuit are black oxide coated replace them with zinc plated silver colored fasteners b If correct voltage is still not indicated check the harness connector terminal for a good connection and crimp to the lead
215. m Service Never attempt to disassemble the ECU It is sealed to prevent damage to internal components Warranty is void if the case is opened or tampered with in any way All operating and control functions within the ECU are preset No internal servicing or readjustment may be performed If a problem is encountered and you determine the ECU to be faulty contact your source of supply Do not replace the ECU without factory authorization The relationship between the ECU and the throttle position sensor TPS is very critical to proper system operation If the TPS or ECU is changed or the mounting position of the TPS is altered the appropriate TPS Initialization Procedure see pages 5B 8 and 5B 9 must be performed to restore the synchronization Engine Speed Sensor Figure 5B 3 Engine Speed Sensor 5B 6 Section 5B EFI Fuel System General The engine speed sensor is essential to engine operation constantly monitoring the rotational speed RPM of the crankshaft A ferromagnetic 60 tooth ring gear with two consecutive teeth missing is mounted on the flywheel The inductive speed sensor is mounted 1 5 0 25 mm 0 059 0 010 in away from the ring gear During rotation an AC voltage pulse is created within the sensor for each passing tooth The ECU calculates engine speed from the time interval between the consecutive pulses The two tooth gap creates an interrupted input signal corresponding to specific cranks
216. m the crankshaft Do not strike the crankshaft or flywheel as these parts could become cracked or damaged Striking the puller or crankshaft can cause the crank gear to move affecting crankshaft endplay Figure 9 52 Removing Flywheel with a Puller 4 Remove the woodruff key Remove Stator and Backing Plates 1 Remove the four screws securing the backing plates and stator wire bracket if so equipped See Figure 9 53 Remove the backing plates and stator wire bracket Figure 9 49 Removing Plastic Grass Screen 2 Remove the four hex flange screws or hex studs and washers Remove the plastic fan from the flywheel See Figure 9 50 Figure 9 50 Removing Fan Remove Flywheel 1 Use a flywheel strap wrench or holding tool see Section 2 to hold the flywheel and loosen the hex flange screw securing the flywheel to the crankshaft See Figure 9 51 NOTE Always use a flywheel strap wrench or holding tool to hold the flywheel when loosening or tightening the flywheel screw Do not use any type of bar or wedge to hold the flywheel Use of such tools could cause the flywheel to become cracked or damaged 9 15 Section 9 Disassembly 9 Figure 9 54 Removing Stator Remove Oil Pan Assembly 1 Remove the ten hex flange screws securing the oil pan to the crankcase See Figure 9 55 Figure 9 53 Removing Backing Plates and Stator Wire Bracket 2 Remove the two hex flange screws and the stator See Figure 9 54
217. m the wire harness and check the sensor resistance separately Resistance value should again be 2375 2625 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 one ohmmeter lead to pin terminal 6 in the main harness connector as in step 4 Connect the other lead to terminal 1 in the sensor plug see diagram Continuity should be indicated Repeat the test between pin terminal 4 and terminal 2 in the sensor plug Figure 5B 9 Oxygen Sensor General The oxygen sensor functions like a small battery generating a voltage signal to the ECU based upon the difference in oxygen content between the exhaust gas and the ambient air The tip of the sensor protruding into the exhaust gas is hollow see cutaway Figure 5B 10 The outer portion of the tip is surrounded by the exhaust gas with the inner portion exposed to the ambient air When the oxygen concentration on one side of the tip is different than that of the other side a voltage signal between 0 2 and 1 0 volts is generated between the electrodes and sent to the ECU The voltage signal tells the ECU if the engine is straying from the ideal 14 7 1 fuel mixture and the ECU then adjusts the injector pulse accordingly 1 2 3 4 5 6 7 8 1 Connection
218. meter Little or no resistance should be measured indicating that the wiring of that particular circuit is OK An illustrated listing of numerical terminal locations for each style of ECU connector is provided on pages 5B 26 and 5B 29 NOTE When performing voltage or continuity tests avoid putting excessive pressure on or against the connector pins Flat pin probes are recommended for testing to avoid spreading or bending the terminals 24 Pin MSE 1 0 Plastic Cased ECU Systems Pin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Function 1 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 Speed Sensor Input Speed Sensor Ground Oxygen Sensor Input Not Used Oxygen Sensor Ground if needed Diagnostic Line Throttle Position Supply Voltage Battery Ground Injector 1 Output Injector 2 Output Main Relay Output Malfunction Indicator Light MIL Not Used Tach Output if needed Not Used Ignition Coil 1 Output Ignition Coil 2 Output TPS Initialization Terminal 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 5B 29 Section 5B EFI Fuel System 5B 32 Pin MSE 1 1 Plastic Cased ECU Systems Pin 1 2 3 4 5 6 7 8 9 1
219. misfire on hard acceleration and or erratic operation may be exhibited Possible Causes 1 TPS Sensor Related a Sensor connector or wiring b Sensor output affected or disrupted by dirt grease oil wear or breather tube position must be to side opposite the TPS c Sensor loose on throttle body manifold 2 Throttle Body Related a Throttle shaft or bearings worn damaged 3 Engine Wiring Harness Related 24 Pin MSE 1 0 Plastic Cased ECU a Pin circuits 4 8 and or 14 damaged wiring connectors b Pin circuits 4 8 and or 14 routed near noisy electrical signal coils alternator c Intermittent 5 volt source from ECU pin circuit 14 3 Engine Wiring Harness Related 32 Pin MSE 1 1 Plastic Cased ECU a Pin circuits 4 8 and or 18 damaged wiring connectors b Pin circuits 4 8 and or 18 routed near noisy electrical signal coils alternator c Intermittent 5 volt source from ECU pin circuit 18 4 ECU Harness Related a ECU to harness connection problem 5B 34 Section 5B EFI Fuel System Code 23 Source ECU Explanation ECU is unable to recognize or process signals from its memory Expected Engine Response Engine will not run Possible Causes 1 ECU internal memory problem a Diagnosable only through the elimination of all other system component faults Code 24 Will not blink out Source Engine Speed Sensor Explanation No tooth signal from speed sensor
220. mm 0 2358 0 2362 in Max Wear Limit 5 977 mm 0 2353 in Governor Lever Nut Torque 6 8 N m 60 in lb 1 13 Section 1 Safety and General Information 1 Ignition Spark Plug Type Champion or Equivalent RC12YC XC12YC or Platinum 3071 Spark Plug Gap 0 76 mm 0 030 in Spark Plug Torque 24 4 29 8 N m 18 22 ft lb Ignition Module Air Gap 0 28 0 33 mm 0 011 0 013 in Ignition Module Fastener Torque 4 0 6 2 N m 35 55 in lb Speed Sensor Air Gap EFI engines 1 50 0 25 mm 0 059 0 010 in Muffler Muffler Retaining Nuts Torque 24 4 N m 216 in lb Oil Filter Oil Filter Torque 3 4 1 turn after gasket contact Oil Cooler Oil Cooler Adapter Nipple Torque
221. move and discard the faulty TPS Install the replacement TPS and secure with the original mounting screws a Reconnect both connector plugs b Perform the appropriate TPS Initialization Procedure integrating the new sensor to the ECU TPS Initialization Procedure For 24 Pin MSE 1 0 Plastic Cased ECU only 1 Check that the basic engine all sensors fuel fuel pressure and battery are good and functionally within specifications Important 2 Remove disconnect all external loads from the engine belts pumps electric PTO clutch alternator rectifier regulator etc 3 Start the engine and allow it to warm up for 5 10 minutes so oil temperature is above 55 C 130 F 4 Move the throttle control to the idle position and allow the engine to stabilize for a minimum of one minute 5 Install a heavy rubber band around the throttle lever and the manifold boss On some EFI engines there is a dampening spring on the end of the idle speed screw The dampening spring if used should be fully compressed and the tab on the throttle lever in direct contact with the speed screw Adjust the idle speed to 1500 RPM using a tachometer 6 Shut off the engine 7 Locate the service connector plug in the wiring harness Connect a jumper wire from the TPS initialization pin 24 violet wire to the battery voltage pin red wire or use the jumper connector plug with the blue jumper wire See Figure 5B 7 5B 9
222. mpion or equivalent spark plugs 2 Set the gap at 0 76 mm 0 030 in Figure 11 44 Installing Spark Plugs Install Ignition Modules 1 Rotate the flywheel to position the magnet away from the ignition module bosses Figure 11 45 Installing Ignition Modules 2 On engines equipped with SMART SPARK both modules are installed the same way with the two tabs out See Figure 11 46 and 11 52 On engines not equipped with SMART SPARK the modules are installed with the spark plug lead wire from module always away from the cylinder On 1 cylinder the single kill tab should be towards you See Figure 11 45 On 2 cylinder the single kill tab should be away from you in 3 Install each ignition module to the crankcase bosses with the two screws hex flange or allen head based on model Slide the modules up as far away from the flywheel as possible and snug the screws to hold them in that position Figure 11 42 Torquing Rocker Arm Screws 4 Use a spanner wrench or rocker arm lifting tool see Section 2 to lift the rocker arms and position the push rods underneath See Figure 11 43 3 Install new plugs and torque to 24 4 29 8 N m 18 22 ft lb See Figure 11 44 11 14 Section 11 Reassembly Figure 11 46 Setting Ignition Module Air Gap 6 Torque the screws to 4 0 6 2 N m 35 55 in lb 7 Repeat steps 4 through 6 for the other ignition module 8 Rotate the flywheel back and forth checki
223. n onto the armature shaft 2 Install and assemble the stop collar retainer assembly a Install the stop collar down onto the armature shaft with the counter bore recess up b Install a new retainer in the larger rear groove of the armature shaft Squeeze with a pliers to compress it in the groove c Slide the stop collar up and lock it into place so the recess surrounds the retainer in the groove If necessary rotate the pinion outward on the armature splines against the retainer to help seat the collar around the retainer Figure 8 61 Installing Stop Collar and Retainer NOTE Always use a new retainer Do not reuse old retainers which have been removed 3 Install the offset thrust stop washer so the smaller offset of the washer faces the retainer collar See Figure 8 62 8 36 Section 8 Electrical System and Components Figure 8 62 Installing Thrust Washer 4 Apply a small amount of oil to the bearing in the drive end cap and install the armature with the drive pinion 5 Lubricate the fork end and center pivot of the drive lever with drive lubricant see Section 2 Position the fork end into the space between the captured washer and the rear of the pinion 6 Slide the armature into the drive end cap and at the same time seat the drive lever into the housing NOTE Correctly installed the center pivot section of the drive lever will be flush or below the machined surface of the hou
224. n Fastener Torque 9 9 N m 88 in lb Flywheel Retaining Screw Torque 66 4 N m 49 ft lb Governor Governor Cross Shaft to Crankcase Running Clearance 6 mm Shaft 0 013 0 075 mm 0 0005 0 0030 in 8 mm Shaft 0 025 0 126 mm 0 0009 0 0049 in Governor Cross Shaft O D 6 mm Shaft New 5 975 6 012 mm 0 2352 0 2367 in Max Wear Limit 5 962 mm 0 2347 in 8 mm Shaft New 7 949 8 000 mm 0 3129 0 3149 in Max Wear Limit 7 936 mm 0 3124 in Governor Gear Shaft to Governor Gear Running Clearance 0 015 0 140 mm 0 0006 0 0055 in Governor Gear Shaft O D New 5 990 6 000
225. nal 3 4 1 turn 8 Fill the engine with the proper oil to the FULL mark on the dipstick Always check the oil level with the dipstick before adding more oil 9 Reinstall the oil fill cap dipstick 10 Start the engine and check for oil leaks Stop the engine correct any leaks and allow a minute for the oil to drain down then recheck the level on the dipstick Service Oil Cooler Some engines are equipped with an oil cooler One style of oil cooler mounts on the engine crankcase and has the oil filter on it See Figure 6 6 The other style of oil cooler is mounted on the blower housing separate from the oil filter See Figure 6 7 Inspect and clean the oil cooler every 100 hours of operation more frequently under severe conditions In order to be effective the oil cooler must be kept free of debris Figure 6 6 Crankcase Mounted Oil Cooler To service the crankcase mounted oil cooler clean off the outside fins with a brush or with compressed air Figure 6 7 Blower Housing Mounted Oil Cooler 6 4 Section 6 Lubrication System To service the blower housing mounted oil cooler clean the outside of the fins with a brush see Figure 6 7 Remove the two screws holding the cooler unit to the blower housing Tilt the cooler downward as shown in Figure 6 8 Clean the inside of the cooler with a brush or with compressed air After cleaning reinstall the oil cooler to the blower housing with the two mounting screws
226. nd pin 17 Resistance should be 4 15 for each circuit 32 Pin MSE 1 1 Plastic Cased ECU Check the resistance between relay terminal 87 and pin 14 in the main connector Then check the resistance between relay terminal 87 and pin 15 Resistance should be 4 15 for each circuit Check all electrical connections connectors and wiring harness leads if resistance is incorrect Injector leakage is very unlikely but in those rare instances it can be internal past the tip of the valve needle or external weeping around the injector body See Figure 5B 19 The loss of system pressure from the leakage can cause hot restart problems and longer cranking times To check for leakage it will be necessary to loosen or remove the blower housing which may involve removing the engine from the unit Figure 5B 17 Checking Injectors 3 Disconnect the 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 NOTE Do not apply voltage to the fuel injector s Excessive voltage will burn out the injector s Do not ground the injector s with the ignition on Injector s will open turn on if relay is energized Listen Here 5B 16 Section 5B EFI Fuel System
227. ne 3 Unthread and remove the oil fill cap dipstick wipe oil off Reinsert the dipstick into the tube and rest the oil fill cap on the tube Do not thread the cap onto the tube See Figure 6 2 NOTE To prevent extensive engine wear or damage always maintain the proper oil level in the crankcase Never operate the engine with the oil level below the low mark or above the full mark on the dipstick Changing Oil and Oil Filter Changing Oil Change the oil after every 100 hours of operation more frequently under severe conditions Refill with service class SG SH SJ or higher oil as specified in the Viscosity Grades table on page 6 1 Change the oil while the engine is still warm The oil will flow more freely and carry away more impurities Make sure the engine is level when filling or checking oil Figure 6 4 Oil Drain Plug Starter Side Operating Range Full Mark Figure 6 3 Oil Level Marks on Dipstick Figure 6 5 Oil Drain Plug Oil Filter Side Oil Drain Oil Drain Oil Filter 6 3 Section 6 Lubrication System 6 Change the oil as follows 1 A drain plug is located on either side of the oil sump one is near the starter the other is near the oil filter See Figures 6 4 and 6 5 Clean the area around the most accessible oil drain plug and the oil fill cap dipstick 2 Remove the selected drain plug and the oil fill cap dipstick 3 Allow the oil to drain and then reinstal
228. ne running at 3600 RPM measure AC voltage across stator leads using an AC voltmeter 2 If voltage is 28 volts or more stator is OK Rectifier regulator is faulty Replace the rectifier regulator If voltage is less than 28 volts stator is probably faulty and should be replaced Test stator further using an ohmmeter Test 3 No Charge to Battery 3a With engine stopped measure the resistance across stator leads using an ohmmeter 3a If resistance is 0 064 0 2 ohms the stator is OK If the resistance is infinity ohms stator is open Replace stator 3b With the engine stopped measure the resistance from each stator lead to ground using an ohmmeter 3b If the resistance is infinity ohms no continuity the stator is OK not shorted to ground If resistance or continuity is measured the stator leads are shorted to ground Replace stator 1 If the voltage is 14 7 volts or less the charging system is OK The battery is unable to hold a charge Service battery or replace as necessary If voltage is more than 14 7 volts the rectifier regulator is faulty Replace rectifier regulator 1 Perform same test as step 1 above Battery Continuously Charges at High Rate 8 23 8 Section 8 Electrical System and Components Troubleshooting Guide 3 Amp Battery Charging System with 70 Watt Lighting Stator NOTE Zero ohmmeters on each scale to ensure accurate readings Voltage tests should be made
229. nformation 1 English Fastener Torque Recommendations for Standard Applications Grade 2 or 5 Fasteners Into Aluminum Size 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 Size 5 16 24 40 7 30 3 8 16 47 5 35 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 Tightening Torque N m ft lb or 20 Tightening Torque N m in lb or 20 Grade 2 Grade 5 Grade 8 Bolts Screws Nuts and Fasteners
230. ng and repair Engine Oil Temperature Sensor Figure 5B 8 Engine Oil Temperature Sensor 5B 10 Section 5B EFI Fuel System Oxygen Sensor General The engine oil temperature sensor Figure 5B 8 is used by the system to help determine fuel requirements for starting a cold engine needs more fuel than one at or near operating temperature Mounted in the oil filter adapter housing it has a temperature sensitive resistor that extends into the oil flow The resistance changes with oil temperature altering the voltage sent to the ECU Using a table stored in its memory the ECU correlates the voltage drop to a specific temperature Using the fuel delivery maps the ECU then knows how much fuel is required for starting at that temperature Service The temperature sensor is a sealed non serviceable assembly A faulty sensor must be replaced If a blink code indicates a problem with the temperature sensor it can be tested as follows 1 Remove the temperature sensor from the adapter housing and cap or block the adapter hole 2 Wipe the sensor clean and allow it to reach room temperature 20 C 68 F 3 Unplug the main harness connector from the ECU 4 With the sensor still connected check the temperature sensor circuit resistance between the 6 and 4 pin terminals see chart on page 5B 26 24 pin or 5B 29 32 pin for pin positions The value should be 2375 2625 5 Unplug the sensor fro
231. ng for clearance between the magnet and ignition modules Make sure the magnet does not strike the modules Check the gap with a feeler gauge and readjust if necessary Final air gap 0 280 0 330 mm 0 011 0 013 in Install Intake Manifold 1 Install the intake manifold and new gaskets or O Rings plastic manifold with wiring harness attached to the cylinder heads Slide any wiring harness clips onto the appropriate bolts before installing Make sure the gaskets are in the proper orientation See Figures 11 47 and 11 48 Using the sequence shown in Figure 11 49 torque the four screws in two stages first to 7 4 N m 66 in lb then to 9 9 N m 88 in lb Figure 11 48 Installing Intake Manifold with Wiring Harness Aluminum Manifold Shown 4 Rotate the flywheel to position the magnet directly under one ignition module 5 Insert a 0 30 mm 0 012 in flat feeler gauge between the magnet and the ignition module see Figure 11 46 Loosen the screws enough to allow the magnet to pull the module against the feeler gauge Figure 11 47 Installing Intake Manifold Gaskets Figure 11 49 Intake Manifold Torque Sequence 1 2 3 4 11 15 Section 11 Reassembly 11 NOTE If the wires were disconnected from the ignition modules on engines with SMART SPARK reattach the leads and seal the base of the terminal connectors with GE Novaguard G661 see Section 2 or Fel Pro Lubri Sel dielectric compound The be
232. nner Baffles 3 Remove the two remaining hex flange screws from the breather cover 4 Pry under the protruding edge of the breather cover with a screwdriver to break the RTV or gasket seal See Figure 9 35 Do not pry on the sealing surfaces as it could cause damage resulting in leaks Most engines use a formed gasket rather than RTV sealant Remove Oil Sentry 1 Disconnect the lead from the Oil Sentry switch 2 Remove the Oil Sentry switch from the breather cover See Figure 9 33 Figure 9 33 Removing Oil Sentry Switch Remove Inner Baffles and Breather Cover 1 Remove the four hex flange screws securing the inner baffles to the crankcase 2 Remove the inner valley baffles See Figure 9 34 9 10 Section 9 Disassembly Figure 9 37 Removing Valve Cover Remove Ignition Modules 1 Disconnect the lead s from each ignition module See Figure 9 38 Figure 9 38 Disconnect Lead s from Ignition Modules 2 Rotate the flywheel so the magnet is away from the modules See Figure 9 39 SMART SPARK Module Leads Fixed Timing Ignition Module Kill Lead Figure 9 36 Removing Breather Cover Gasket Remove Valve Covers Three valve cover designs have been used The earliest type used a gasket and RTV sealant between the cover and sealing surface of the cylinder head The second type had a black O Ring installed in a groove on the underside of the cover and may have metal spacers in the bolt holes
233. nning Clearance New 0 03 0 09 mm 0 0012 0 0035 in Crankshaft Bore In Oil Pan New 40 987 40 974 mm 1 6136 1 6131 in Crankshaft Bore In Oil Pan to Crankshaft Running Clearance New 0 039 0 074 mm 0 0015 0 0029 in Flywheel 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 0 022 mm 0 0009 in Max Out of Round 0 025 mm 0 0010 in Oil Pan 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 0 022 mm 0 0009 in Max Out of Round
234. no gap present the lever should be replaced If not already installed position the governor lever on the cross shaft but leave the clamping screw loose Figure 5B 39 Adjusting Governor Shaft 5B 25 Section 5B EFI Fuel System 5B 4 Verify that the governor has been set correctly With the linkage still retained in the Full Throttle position Step 2 unsnap the bushing clip separate the linkage from the bushing and remove the bushing from the lever Follow Steps 3 and 4 in Checking the Initial Adjustment 5 Reconnect the dampening spring into its governor lever hole from the bottom Reinstall the bushing and reattach the throttle linkage See Figure 5B 34 Reattach the governor spring in the marked hole 6 Start the engine and allow it to fully warm up and establish closed loop operation approximately 5 10 min Check the speed settings and adjust as necessary first the low idle speed and then the high speed setting Troubleshooting General When troubleshooting a problem on an engine with EFI basic engine operating problems must be eliminated first before faulting the EFI system components What appears to be an EFI problem could be something as simple as a fuel tank with debris in the bottom or a plugged vent Be sure the engine is in good mechanical operating condition and all other systems are operating properly before attempting to troubleshoot the EFI system Troubleshooting Guide
235. nor shaft Oil Pump Assembly Disassembly 1 Remove the two hex flange screws 2 Remove the oil pump assembly from the oil pan Disassembly The governor gear must be replaced once it is removed from the oil pan NOTE The governor gear is held onto the shaft by small molded tabs in the gear When the gear is removed from the shaft these tabs are destroyed and the gear must be replaced Therefore remove the gear only if absolutely necessary 1 Remove the regulating pin and governor gear assembly See Figure 10 13 Figure 10 14 Governor Shaft Press Depth Figure 10 15 Removing Oil Pump 3 Remove the oil pump rotor If a plastic pickup is used See Figures 10 15 and 10 17 unhook the locking clip and carefully pull it free from the oil pump housing 4 If the relief valve is like that shown in Figure 10 16 drive out the pin to remove the oil pressure relief valve piston and spring Refer to the following inspection and reassembly procedures If the relief valve is a one piece style staked to the oil pump housing See Figures 10 15 and 10 17 removal should not be attempted nor is internal servicing possible If a problem with the relief valve is encountered the oil pump should be replaced Mounting Screws Relief Valve Pickup Gear Shaft 34 0 mm 1 3386 in 33 5 mm 1 3189 in 19 40 mm 0 7638 in 10 13 Section 10 Inspection and Reconditioning 10 Figure 10 16 Oil Pump Oil Pic
236. ny way Figure 4 9 Heavy Duty Air Cleaner To Service Every 250 hours of operation more often under extremely dusty or dirty conditions replace the paper element and check the inner element Follow these steps 1 Unhook the two retaining clips and remove the end cap from the air cleaner housing 2 Pull the air cleaner element out of the housing See Figure 4 10 Figure 4 10 Removing Elements 3 After the element is removed check the condition of the inner element It should be replaced whenever it appears dirty typically every other time the main element is replaced Clean the area around the base of the inner element before removing it so dirt does not get into the engine 4 Do not wash the paper element and inner element or use compressed air this will damage the elements Replace dirty bent or damaged elements with new genuine Kohler elements as required Handle the new elements carefully do not use if the sealing surfaces are bent or damaged 5 Check all parts for wear cracks or damage Replace any damaged components 6 Install the new inner element followed by the outer element Slide each fully into place in the air cleaner housing 7 Reinstall the end cap so the dust ejector valve is down and secure with the two retaining clips See Figure 4 9 Inner Element Element 4 6 Section 4 Air Cleaner and Air Intake System Air Intake Cooling System To ensure proper cooling make sure the
237. obtained retighten the lock nut NOTE When the throttle and choke control cables are routed side by side especially under a single clamp there must be a small gap between the cables to prevent internal binding After the high speed setting has been completed check that there is a gap of at least 0 5 mm 0 020 in between the control cables Figure 5 67 Governor Control Connections Choke Control Cable Throttle Control Cable Z Bend Choke Linkage Throttle Control Lever 2 Choke Control Lever 1 Kill Switch Choke Control Cable Throttle Control Cable Kill Switch Adjusting Screw Dual Control High Speed Lever Stop Screw Do Not Remove High Speed Control Lever High Speed Adjusting Screw Left Side Pull Right Side Pull 5 32 Section 5 Fuel System and Governor Choke Lever Detail Figure 5 68 Governor Used with Commercial Mower Air Cleaner CV17 745 Commercial Mower Governor Arrangement The Commercial Mower governor arrangement shown in Figure 5 68 is used primarily on wide area walk behind mower applications The initial adjustment and sensitivity adjustment is the same as for the standard governor The governor and controls for the CV750 engine is shown in Figure 5 69 Should the governor spring be disconnected from the throttle lever and governor lever reconnect it as follows 1 Hook the long end of the spring through the hole in the lever from the left side 2 Rotate
238. od using the two hex flange screws Three different types of connecting rod bolts have been used and each has a different torque value If 8 mm straight shank type bolts are used torque in increments to 22 7 N m 200 in lb If 8 mm step down bolts are used torque in increments to 14 7 N m 130 in lb If 6 mm straight shank bolts are used torque in increments to 11 3 N m 100 in lb Illustrated instructions are provided in the service rod package See Figures 11 10 and 11 11 NOTE Align the chamfer of the connecting rod with the chamfer of its mating end cap When installed the flat faces of the connecting rods should face each other The faces with the raised rib should be toward the outside 11 4 Section 11 Reassembly Figure 11 13 Aligning Crankshaft and Camshaft Timing Marks Figure 11 11 Torquing Connecting Rod End Cap 6 Repeat the above procedure for the other connecting rod and piston assembly Install Camshaft 1 Liberally apply camshaft lubricant see Section 2 to each of the cam lobes Lubricate the camshaft bearing surfaces of the crankcase and camshaft with engine oil See Figure 11 12 Figure 11 12 Apply Camshaft Lubricant to Cam Lobes 2 Position the timing mark of the crankshaft gear at the 12 o clock position 3 Turn the governor cross shaft clockwise until the lower end of the shaft contacts the cylinder Make sure the cross shaft remains in this position while installing t
239. of dirt or foreign material before disassembling the carburetor Remove the four mounting screws and separate the fuel bowl from the carburetor Transfer any remaining fuel into an approved container Remove and discard the old O Rings Fuel can also be drained prior to bowl removal by loosening removal of the bowl drain screw See Figure 5 49 Figure 5 49 Fuel Bowl Removed From Carburetor NOTE Further disassembly of the fuel bowl is not necessary unless the Fuel Solenoid Kit or Fuel Bowl Kit obtained separately will also be installed 2 Remove the float pin screw and lift out the old float pin and inlet needle See Figure 5 50 Discard all the old parts The seat for the inlet needle is not serviceable and should not be removed Fuel Bowl Bowl Drain Screw 5 25 Section 5 Fuel System and Governor 5 Figure 5 53 Slow Jets and O Ring Detail 5 Remove the idle speed RPM adjustment screw and spring from the carburetor Discard the parts NOTE The carburetor is now disassembled for appropriate cleaning and installation of the parts in the overhaul kit Further disassembly is not necessary The throttle shaft assembly fuel inlet seat idle fuel adjustment screws with limiter and carburetor body are non serviceable items and should not be removed The choke shaft assembly is serviceable however it should not be removed unless a Choke Repair Kit will be installed 6 Clean the carburetor body main jet
240. older mounting screws Torque the thru bolts to 5 6 9 0 N m 49 79 in lb Torque the brush holder mounting screws to 2 5 3 3 N m 22 29 in lb See Figures 8 71 and 8 72 Figure 8 72 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 14 Connect the positive brush lead bracket to the solenoid and secure with the hex nut Torque the nut to 8 11 N m 71 97 in lb Do not overtighten See Figure 8 73 Figure 8 71 Torquing Thru Bolts Figure 8 73 Positive Brush Lead Connection 8 39 8 Section 8 Electrical System and Components 12 volt Test Leads Momentary Connection Only 12 volt Test Leads Momentary Connection Only VOM Leads Manually Push Plunger In 12 volt Test Leads Connect Only Long Enough to Test Solenoid Test Procedure Solenoid Shift Style Starters Disconnect all leads from the solenoid including the positive brush lead attached to the lower stud terminal Remove the mounting hardware and separate the solenoid from the starter for testing Test 1 Solenoid Pull In Coil Plunger Actuation Test Use a 12 volt power supply and two test leads Connect one lead to the flat spade S start terminal
241. oling shrouds clogged 2 Excessive engine load 3 Low crankcase oil level 4 High crankcase oil level 5 Faulty carburetor 6 Lean fuel mixture 7 SMART SPARK malfunction applicable models Engine Knocks 1 Excessive engine load 2 Low crankcase oil level 3 Old or improper fuel 4 Internal wear or damage 5 Hydraulic lifter malfunction 6 Quality of fuel 7 Incorrect grade of oil Engine Loses Power 1 Low crankcase oil level 2 High crankcase oil level 3 Dirty air cleaner element 4 Dirt or water in the fuel system 5 Excessive engine load 6 Engine overheated 7 Faulty spark plugs 8 Low compression 9 Exhaust restriction 10 SMART SPARK malfunction applicable models 11 Low battery 12 Incorrect governor setting Engine Uses Excessive Amount of Oil 1 Incorrect oil viscosity type 2 Clogged or improperly assembled breather 3 Breather reed broken 4 Worn or broken piston rings 5 Worn cylinder bore 6 Worn valve stems valve guides 7 Crankcase overfilled 8 Blown head gasket overheated Oil Leaks from Oil Seals Gaskets 1 Crankcase breather is clogged or inoperative 2 Breather reed broken 3 Loose or improperly torqued fasteners 4 Piston blowby or leaky valves 5 Restricted exhaust External Engine Inspection Before cleaning or disassembling the engine make a thorough inspection of its external appearance and condition This inspection can give clue
242. oling agent is recommended 2 With the lower edge of each stone positioned even with the lowest edge of the bore start drill and honing process Move the hone up and down while resizing to prevent the formation of cutting ridges Check the size frequently 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 the new diameter Section 1 The corresponding oversize Kohler replacement piston will then fit correctly 3 When the bore is within 0 064 mm 0 0025 in of the desired size remove the coarse stones and replace them with burnishing stones Continue with the burnishing stones until the bore is within 0 013 mm 0 0005 in of the desired size and then use finish stones 220 280 grit and polish the bore to its final size A crosshatch should be observed if honing is done correctly The crosshatch should intersect at approximately 23 33 off the horizontal Too flat an angle could cause the rings to skip and wear excessively and too steep an angle will result in high oil consumption See Figure 10 3 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 Check the cylinder bore for scoring In severe cases unburned fuel can cause scuffing and scoring of the cylinder wall It washes the nece
243. on Starter Does Not Energize Starter Energizes but Turns Slowly Battery Wiring Starter Switch or Solenoid Brushes Transmission or Engine Battery NOTE If the starter does not crank the engine shut off the starter immediately Do not make further attempts to start the engine until the condition is corrected NOTE Do not drop the starter or strike the starter frame Doing so can damage the starter Starter Removal and Installation Refer to the Disassembly and Reassembly Sections for starter removal and installation procedures Inertia Drive Electric Starters This subsection covers the operation troubleshooting and repair of the inertia drive and permanent magnet electric starters Troubleshooting Guide Starting Difficulties 8 25 8 Section 8 Electrical System and Components Operation Inertia Drive Starters When power is applied to the starter the armature rotates As the armature rotates the drive pinion moves out on the drive shaft splines and into mesh with the flywheel ring gear When the pinion reaches the end of the drive shaft it rotates the flywheel and cranks the engine When the engine starts the flywheel rotates faster than the starter armature and drive pinion This moves the drive pinion out of mesh with the ring gear and into the retracted position When power is removed from the starter the armature stops rotating and the drive pinion is held in
244. or an F at the end of the cycle the SAM is probably bad Recheck all of the connections check the condition of the tester battery and repeat the test If you get the sign and or F again in the retest replace that SAM IMPORTANT Allow 15 20 seconds for the tester to clear and reset itself between tests or if the test is interrupted before completion of the test cycle Otherwise a false reading may be displayed in the form of a or a faint 8 3 Disconnect the yellow and brown tester leads from the long module leads Connect the brown tester lead to the short brown module lead Connect the yellow tester lead to the short yellow or pink module lead See Figure 8 13 Leave the red and green leads connected Repeat step 2 Figure 8 13 The tester is powered by a 9 volt battery Most SAMs are designed to operate down to a minimum of 7 25 volts If the tester battery drops below that level incorrect test readings will result The tester battery should be checked periodically by connecting a DC voltmeter between the red and green lead wires with the tester connected to a SAM Press and hold the test button for a full test cycle F or P appears and then display shuts off while monitoring the voltage reading on the voltmeter If the voltage drops below 7 5 at any time during the cycle the 9 volt tester battery must be replaced Use an extended life alkaline battery To r
245. or reassembly Do not mix end caps and connecting rods Remove Connecting Rods with Pistons and Rings 1 Remove the two hex flange screws securing the closest connecting rod end cap Remove the end cap See Figure 9 60 Figure 9 61 Removing Connecting Rod and Piston Assembly Figure 9 58 Removing Governor Cross Shaft Retainer 8 mm Shaft Design 2 Remove the cross shaft through the inside of the crankcase See Figure 9 59 Figure 9 57 Removing Governor Cross Shaft Hitch Pin 6 mm Shaft Design Figure 9 59 Removing Governor Cross Shaft 9 17 Section 9 Disassembly 9 3 Repeat the above procedure for the other connecting rod and piston assembly Remove Crankshaft 1 Carefully pull the crankshaft from the crankcase See Figure 9 62 Figure 9 62 Removing Crankshaft Figure 9 63 Removing Oil Seal Remove Flywheel End Oil Seal 1 Remove the oil seal from the crankcase See Figure 9 63 10 1 Section 10 Inspection and Reconditioning 10 Section 10 Inspection and Reconditioning This section covers the operation inspection and repair reconditioning of major internal engine components The following components are not covered in this section They are covered in sections of their own Air Cleaner Section 4 Carburetor amp External Governor Section 5 Ignition Charging amp Electric Starter Section 8 Clean all parts thoroughly Only clean parts can be accurately inspected and gauged f
246. or wear or damage There are many commercially available cleaners that will quickly remove grease oil and grime from engine parts When such a cleaner is used follow the manufacturer s instructions and safety precautions carefully Make sure all traces of the cleaner are removed before the engine is reassembled and placed into operation Even small amounts of these cleaners can quickly break down the lubricating properties of engine oil Use an aerosol gasket remover paint stripper or lacquer thinner to remove any old sealant Apply the solvent allow time for it to work and then brush the surface with a brass wire brush After the old sealant is removed clean the surface with isopropyl alcohol lacquer thinner or aerosol electrical contact cleaner Do not scrape the surfaces as any scratches nicks or burrs can result in leaks See Service Bulletin 252 for further information Refer to A Guide to Engine Rebuilding TP 2150 A for additional information Measurement Guide TP 2159 B and Engine Inspection Data Record TP 2435 are also available use these to record inspection results Automatic Compression Release ACR Some engines are equipped with the optional Automatic Compression Release ACR mechanism The ACR lowers compression at cranking speeds to make starting easier Operation The ACR mechanism consists of a flyweight spring and pivoting control pin assembly attached to the gear on the camshaft At cranking spe
247. over 2 Remove the wing nut from the element cover 9 3 Section 9 Disassembly 9 Figure 9 8 Removing Commercial Mower Element and Precleaner Figure 9 6 Removing Standard Element and Precleaner 3 Remove the element cover element and precleaner See Figure 9 6 Figure 9 7 Removing Standard Air Cleaner Base 4 Remove the two hex flange nuts securing the spitback cup baffle or bracket and air cleaner base See Figure 9 7 Two additional lower screws must be removed if the engine contains a lower air cleaner support bracket Figure 9 9 Disconnect Breather Hose from Base 5 Disconnect the breather tube from the nipple on the underside or the hose from the base as equipped See Figure 9 9 6 Remove the base and gasket while carefully pulling the rubber breather tube through the base Hex Flange Nuts 2 Lower Mounting Screws Some Models 9 4 Section 9 Disassembly Figure 9 11 Air Cleaner Bracket Valve Cover Mounting Screws Two Barrel Model Pictured Heavy Duty Air Cleaner 1 Disconnect the breather hose from the fitting in adapter or elbow Remove the hex flange nuts securing the adapter and any attached clips to the mounting studs See Figure 9 10 Figure 9 13 Removing Heavy Duty Air Cleaner Assembly Two Barrel Model Pictured Remove Control Panel If So Equipped 1 Disconnect the Oil Sentry Indicator Light wires 2 Disconnect the choke control cable from the thrott
248. p gear loose out of alignment 3 Engine Wiring Harness Related 24 Pin MSE 1 0 Plastic Cased ECU a Pin circuits 9 and or 10 wiring or connectors b Shielding for pin circuits 9 and or 10 damaged or not properly grounded c Poor or improper grounds in system battery ECU oxygen sensor shielding fuel pump ignition output d Pin circuits 9 and or 10 routed near noisy electrical signals coils spark plug lead plug connector 3 Engine Wiring Harness Related 32 Pin MSE 1 1 Plastic Cased ECU a Pin circuits 9 and or 10 wiring or connectors b Shielding for pin circuits 9 and or 10 damaged or not properly grounded c Poor or improper grounds in system battery ECU oxygen sensor shielding fuel pump ignition output d Pin circuits 9 and or 10 routed near noisy electrical signals coils spark plug lead plug connector 4 ECU Harness Related a ECU to harness connection problem 5 Ignition System Related a Non resistor spark plug s used Code 22 Source Throttle Position Sensor TPS Explanation Unrecognizable signal is being sent from sensor too high too low inconsistent Expected Engine Response A limp home operating mode occurs with an overall decrease in operating performance and efficiency Fuel delivery is based upon the oxygen sensor and five mapped values only Rich running black smoke will occur until closed loop operation is initiated A stumble or
249. park Advance SMART SPARK SMART SPARK equipped engines utilize an electronic capacitive discharge ignition system with electronic spark advance A typical application Figure 8 6 consists of the following components A magnet assembly which is permanently affixed to the flywheel Two electronic capacitive discharge ignition modules which mount on the engine crankcase Figure 8 6 A spark advance module which mounts to the engine shrouding Figure 8 7 A 12 volt battery which supplies current to the spark advance module A kill switch or key switch which grounds the spark advance module to stop the engine Two spark plugs Figure 8 7 Block Diagram Spark Advance Module Figure 8 6 Capacitive Discharge Ignition System with Spark Advance The timing of the spark is controlled by the location of the flywheel magnet group as referenced to engine top dead center and the delay created by the spark advance module Power Source Pulse Generator Reset Circuit B 12 VDC Red Yellow To Semi Conductor Switch Comparator Delay Circuit Charge Pump Conditioning Circuit V 7 2V Brown From Input Coil Green or Black 8 7 8 Section 8 Electrical System and Components Operation The ignition module for this system operates in the same fashion as the fixed timing module except the trigger circuit for the semiconductor L2 Figure 8 5 is replaced by
250. peatedly until the correct test number appears on the display After a few seconds the test number will flash three times and the test will begin A reverse numerical sequence will be displayed starting with a 6 and progressing down to 1 followed by a P pass or F fail indicating the condition of the part See Figures 8 15 and 8 16 If testing an ASAM return to step 1 and move the yellow and brown tester leads to the short set of module leads then repeat the test 8 14 Section 8 Electrical System and Components Figure 8 16 Pass Indicator The tester is powered by a 9 volt battery Most SAMs are designed to operate down to a minimum of 7 25 volts If the tester battery drops below that level incorrect test readings will result The tester battery should be checked periodically by connecting a DC voltmeter between the red and green lead wires with the tester connected to a SAM Press and hold the test button for a full test cycle F or P appears and then display shuts off while monitoring the voltage reading on the voltmeter If the voltage drops below 7 5 at any time during the cycle the 9 volt tester battery must be replaced Use an extended life alkaline battery To replace the battery remove the outer set of screws on the faceplate and carefully lift the panel from the body Unplug the connector and pull battery with mounting tape off the back of the tester Attach the
251. performance If problem persists go to Test 3 b If one cylinder had good spark but the other cylinder had no spark or intermittent spark go to Test 3 c If there was no spark or intermittent spark on both cylinders go to Test 4 8 9 8 Section 8 Electrical System and Components Figure 8 8 1 Make a line near the edge of the flywheel screen with a marking pen or narrow tape 2 Connect an automotive timing light to cylinder that had good spark Test 4 Test the ignition modules and connections 1 Remove the blower housing from the engine Inspect the wiring for any damage cuts bad crimps loose terminals or broken wires 2 Disconnect the leads from the ignition module s and clean all of the terminals male and female with aerosol electrical contact cleaner to remove any old dielectric compound dark residue dirt or contamination Disconnect the spark plug leads from the spark plugs 3 Remove one of the mounting screws from each of the ignition modules If the mounting screws are black remove them both and discard Replace them with part number M 561025 S Look in the mounting hole with a flashlight and use a small round wire brush to remove any loose rust from the laminations inside the mounting hole 4 Refer to the chart on page 8 10 to identify which ignition module s you have If they are the smaller style check the vendor part number on the face All modules with vendor part numbers MA 2 M
252. pressing the center pin 8 The correct float height setting is 17 mm 0 669 in 1 5 mm 0 059 in measured from the float bottom to the body of the carburetor See Figure 5 47 Replace the float if the height is different than the specified setting Do not attempt to adjust by bending float tab 5 24 Section 5 Fuel System and Governor Figure 5 50 Removing Float and Inlet Needle 3 Use an appropriate size flat screwdriver and carefully remove the two main jets from the carburetor Note and mark the jets by location for proper reassembly The main jets may be size side specific After the main jets are removed the main nozzles can be removed out through the bottom of the main towers Note the orientation direction of the nozzles The end with the two raised shoulders should be out down adjacent to the main jets Save the parts for cleaning and reuse See Figure 5 51 Figure 5 47 Checking Float Height NOTE Be sure to measure from the casting surface not the rubber gasket if still attached 9 When the proper float height is obtained carefully reinstall the fuel bowl using new O Rings onto the carburetor Secure with the four original screws Torque the screws to 2 5 0 3 N m 23 2 6 in lb See Figure 5 48 Figure 5 48 Installing Fuel Bowl 10 Install the carburetor and the heavy duty air cleaner as outlined in Section 11 Reassembly Disassembly Overhaul 1 Clean the exterior surfaces
253. r Service Check the air cleaner daily or before starting the engine Check for and correct any buildup of dirt and debris along with loose or damaged components NOTE Operating the engine with loose or damaged air cleaner components could allow unfiltered air into the engine causing premature wear and failure Precleaner Service Standard and Commercial Mower Types If so equipped wash and reoil the precleaner every 25 hours of operation more often under extremely dusty or dirty conditions To service the precleaner see Figures 4 3 or 4 4 and perform the following steps 1 Loosen the cover retaining knob or unhook the latches 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 the precleaner with new engine oil Squeeze out all excess oil 5 Reinstall the precleaner over the paper air cleaner element 6 Reinstall the air cleaner cover Secure the cover with the two latches or the retaining knob Figure 4 2 Commercial Mower Air Cleaner 4 2 Section 4 Air Cleaner and Air Intake System Figure 4 4 Precleaner on Commercial Mower Type Air Cleaner Figure 4 3 Precleaner on Standard Air Cleaner Paper Element Service Standard and Commercial Mower Typ
254. r troubleshooting guide indicate float level problems remove the carburetor from the engine to check and or replace the float Use a float kit to replace float pin and inlet needle or valve 1 Remove the air cleaner and air intake components from the carburetor as described in Section 4 2 Disconnect the fuel inlet line from the carburetor 3 Disconnect governor throttle linkage from the carburetor 4 Disconnect lead wires from fuel solenoid equipped carburetor Governed Idle Spring Tab Hold Throttle Lever Against Screw 5 Slide the carburetor off the retaining studs Remove the fuel bowl retaining screw or fuel shut off solenoid and drain the fuel into a safe container Remove the bowl from the carburetor body Figure 5 9 Proper Float Level 6 Turn the carburetor body upside down and check the float level as shown in Figure 5 9 With the float needle valve fully seated 16 5 mm 0 65 in should be measured from the body to the float as indicated Don t attempt to adjust by bending the tab replace the float with a kit if the level is wrong 7 Pull the float hinge pin and remove the float with the inlet needle attached to inspect the needle and seat If dirty blow out with compressed air Replace the float components as needed with the kit 8 Using new gaskets reinstall the bowl and tighten the bowl retaining screw or solenoid to 5 1 6 2 N m 45 55 in lb 9 Reinstall the carburetor on t
255. r section 2 Engine Wiring Harness Related a Pin circuit wiring or connectors Pin 11 for 24 Pin MSE 1 0 Plastic Cased ECU Pin 20 for 32 Pin MSE 1 1 Plastic Cased ECU 3 Low Fuel Pressure 4 Oxygen Sensor Related a Sensor connector or wiring problem b Exhaust leak c Poor ground path to engine sensor is case grounded 5 Poor system ground from ECU to engine causing rich running while indicating lean Code 32 Source Oxygen Sensor Explanation No change in the sensor output signal Expected Engine Response Open loop operation only may cause a drop in system performance and fuel efficiency Possible Causes 1 Engine Wiring Harness Related a Pin circuit 11 wiring or connectors Pin 11 for 24 Pin MSE 1 0 Plastic Cased ECU Pin 20 for 32 Pin MSE 1 1 Plastic Cased ECU 2 Oxygen Sensor Related a Sensor connector or wiring problem b Sensor contaminated or damaged c Sensor below the minimum operating temperature 375 C 709 F d Poor ground path from sensor to engine sensor grounds through shell see Oxygen Sensor section 5B 35 Section 5B EFI Fuel System 5B Code 33 Source Oxygen Sensor Fuel System Explanation System too Rich Temporary fuel adaptation control is at the upper limit Expected Engine Response Erratic performance Will run rich smoke Possible Causes 1 Fuel Supply Related nothing lean only rich a
256. rcuits at the proper times Service A malfunctioning relay can result in starting or operating difficulties The relay and related wiring can be tested as follows 1 Disconnect the relay connector plug from the relay 5B 13 Section 5B EFI Fuel System 5B Figure 5B 12 Relay Connector 3 Set meter for DC voltage Touch red tester lead to the 30 terminal in relay connector A reading of 12 volts should be indicated at all times 4 Connect the red lead of meter to the 85 terminal in relay connector Turn key switch to the on position Battery voltage should be present a No voltage present indicates a problem with the key switch in the wiring or at the connector b If voltage is present the wiring to the connector is good Turn the ignition switch off and proceed to Step 5 to test therelay Terminal 87 Feed To Ignition Coils Fuel Injectors and Fuel Pump Terminal 86 ECU Controlled Ground Terminal 87A Not used Terminal 85 Ignition Switch Voltage Terminal 30 Permanent Battery Voltage Terminal 85 Ignition Switch Voltage Terminal 87 Feed To Ignition Coils Fuel Injectors and Fuel Pump Terminal 86 ECU Controlled Ground Terminal 30 Permanent Battery Voltage Terminal 87A Not used Figure 5B 14 Style 1 Fuel Injector 2 Connect the black lead of VOA meter to a chassis ground location Connect the red lead to the 86 termin
257. re 5 59 Installing Fuel Bowl Choke Repair 1 Remove the carburetor from the engine Discard the old mounting gaskets for the air cleaner and carburetor 2 Clean the areas around the choke shaft and the self relieving choke mechanism thoroughly 3 Remove and discard the plastic cap from the end of the choke lever shaft assembly 4 Note the position of the spring legs and the choke plate for correct reassembly later See Figure 5 60 Remove the two screws attaching the choke plate to the choke shaft Pull the shaft out of the carburetor body and discard the removed parts Figure 5 61 Assembling Choke Lever Stops Boss 5 28 Section 5 Fuel System and Governor Figure 5 63 Choke Shaft and Spring Details 10 Slide the choke shaft and spring into the carburetor Pivot preload the shaft and set the inner leg of the spring against the formed stop within the choke lever as originally assembled See Figure 5 60 The opposing leg of the spring must still be between the formed stops of the choke shaft 8 Turn the old bushing upside down and use it as a driver to carefully press or tap the new bushing into the carburetor body until it bottoms Check that the choke lever pivots freely without restriction or binding See Figure 5 62 Figure 5 62 Installing Bushing 9 Install the new return spring onto the new choke shaft so the upper leg of the spring is between the two formed stops on the end of the
258. rmined by the position of the throttle control It can be variable or constant depending on the engine application Governor General The engine is equipped with a centrifugal flyweight mechanical governor It is designed to hold the engine speed constant under changing load conditions The governor gear flyweight mechanism is mounted inside the crankcase on the oil pan and is driven off the gear on the camshaft The governor works as follows Centrifugal force acting on the rotating governor gear assembly causes the flyweights to move outward as speed increases Governor spring tension moves them inward as speed decreases As the flyweights move outward they cause the regulating pin to move outward The regulating pin contacts the tab on the cross shaft causing the shaft to rotate One end of the cross shaft protrudes through the crankcase The rotating action of the cross shaft is transmitted to the throttle lever of the carburetor through the external linkage See Figure 5 66 When the engine is at rest and the throttle is in the fast position the tension of the governor spring holds the throttle plate open When the engine is operating the governor gear assembly is rotating The force applied by the regulating pin against the cross shaft tends to close the throttle plate The governor spring tension and the force applied by the regulating pin balance each other during operation to maintain engine
259. rough the hole in the base Figure 4 8 Removing Base on Commercial Mower Type Air Cleaner Disassembly Reassembly Commercial Mower Type If the base has to be separated from the carburetor proceed as follows 1 Remove the air cleaner components from the air cleaner base see Figure 4 6 2 Remove the two nuts holding the air cleaner base to the carburetor see Figure 4 8 3 Remove the tube from the base 4 Separate the base from the carburetor 5 Reverse procedure to reassemble components Torque air cleaner base mounting nuts to 6 2 7 3 N m 55 65 in lb 4 Remove the base and gasket Carefully feed the breather hose through the base 5 Reverse procedure to reassemble components Torque the two hex flange nuts to 6 2 7 3 N m 55 65 in lb and the two lower M5 mounting screws where applicable to 4 0 N m 35 in lb Mounting Nuts 2 Breather Hose Baffle Seal Lower Base Mounting Screws Base 4 5 Section 4 Air Cleaner and Air Intake System 4 Heavy Duty Air Cleaner General The heavy duty air cleaner consists of a cylindrical housing typically mounted to a bracket and connected with a formed rubber hose to an adapter on the carburetor or throttle body intake manifold EFI units The air cleaner housing contains a paper element and inner element designed for longer service intervals The system is CARB EPA certified and the components should not be altered or modified in a
260. s and never run the engine in a closed building or confined area Spring Under Tension Retractable starters contain a powerful recoil spring that is under tension Always wear safety goggles when servicing retractable starters and carefully follow instructions in Retractable Starter Section 7 for relieving spring tension Explosive Gas Batteries produce explosive hydrogen gas while being charged To prevent a fire or explosion charge batteries only in well ventilated areas Keep sparks open flames and other sources of ignition away from the battery at all times Keep batteries out of the reach of children Remove all jewelry when servicing batteries Before disconnecting the negative ground cable make sure all switches are OFF If ON a spark will occur at the ground cable terminal which could cause an explosion if hydrogen gas or gasoline vapors are present Explosive Fuel can cause fires and severe burns Do not fill the fuel tank while the engine is hot or running WARNING Explosive Fuel Gasoline is extremely flammable and its vapors can explode if ignited Store gasoline only in approved containers in well ventilated unoccupied buildings away from sparks or flames Do not fill the fuel tank while the engine is hot or running since spilled fuel could ignite if it comes in contact with hot parts or sparks from ignition Do not start the engine near spilled fuel Never use gasoline as a cleaning agen
261. s vent ports seats etc using a good commercially available carburetor solvent Keep away from plastic or rubber parts if non compatible Use clean dry compressed air to blow out the internal channels and ports Do not use metal tools or wire to clean orifices and jets Inspect and thoroughly check the carburetor for cracks wear or damage Inspect the fuel inlet seat for wear or damage Check the spring loaded choke plate to make sure it moves freely on the shaft 7 Clean the carburetor fuel bowl as required 8 Install the two main nozzles into the towers of the carburetor body The end of the main nozzles with the two raised shoulders should be out down adjacent to the main jets Make sure the nozzles are completely bottomed Carefully install the main jets into the towers of the carburetor body on the appropriate side as identified when removal was performed See Figure 5 54 Figure 5 51 Main Jets and Nozzles Removed 4 Remove the screw securing the flat washer and ground lead if equipped from the top of the carburetor then carefully pull lift out the two slow jets The slow jets may be size side specific mark or tag for proper reassembly Note the small O Ring on the bottom of each jet See Figure 5 52 and 5 53 Save parts for cleaning and reuse unless a Jet Kit is also being installed Clean the slow jets using compressed air Do not use wire or carburetor cleaner Figure 5 52 Removing Screw and Washer M
262. s CV Series with Commercial Mower Air Cleaner Dimensions in millimeters Inch equivalents shown in 1 8 Section 1 Safety and General Information Figure 1 6 Typical Engine Dimensions CV EFI Series with Heavy Duty Air Cleaner Dimensions in millimeters Inch equivalents shown in 1 9 Section 1 Safety and General Information 1 General Specifications1 Power 3600 RPM exceeds Society of Automotive Engineers Small Engine Test Code J1940 CV17 12 7 kW 17 HP CV18 13 4 kW 18 HP CV20 14 9 kW 20 HP CV22 16 4 kW 22 HP CV23 17 2 kW 23 HP CV25 CV730 18 6 kW 25 HP CV26
263. s a fuel for Kohler EFI engines Other gasoline ether blends are not approved EFI Fuel System Components General The Electronic Fuel Injection EFI system is a complete engine fuel and ignition management design The system includes the following principal components Fuel Pump Fuel Filter Fuel Rail Fuel Line s Fuel Pressure Regulator Fuel Injectors Throttle Body Intake Manifold Engine Control Unit ECU Ignition Coils Engine Oil Temperature Sensor Throttle Position Sensor TPS Speed Sensor Oxygen Sensor Wire Harness Assembly amp Affiliated Wiring Malfunction Indicator Light MIL Operation The EFI system is designed to provide peak engine performance with optimum fuel efficiency and lowest possible emissions The ignition and injection functions are electronically controlled monitored and continually corrected during operation to maintain the theoretical ideal or stoichiometric air fuel ratio of 14 7 1 The central component of the system is the Motronic Engine Control Unit ECU which manages system operation determining the best combination of fuel mixture and ignition timing for the current operating conditions An electric fuel pump is used to move fuel from the tank through the 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 the tank
264. s thoroughly reassemble and recheck pressure 2 Replace all worn or damaged seals and gaskets Make sure all fasteners are tightened securely Use appropriate torque values and sequences when necessary 3 Recondition piston rings cylinder bore valves and valve guides 4 Repair replace restricted muffler exhaust system 1 Crankcase breather clogged or inoperative 2 Seals and or gaskets leaking Loose or improperly torqued fasteners 3 Piston blowby or leaky valves confirm by inspecting components 4 Restricted exhaust No Crankcase Vacuum Pressure in Crankcase Compression Test Some of these engines are equipped with an automatic compression release ACR mechanism Because of the ACR mechanism it is difficult to obtain an accurate compression reading As an alternative perform a cylinder leakdown test Cylinder Leakdown Test A cylinder leakdown test can be a valuable alternative to a compression test By pressurizing the combustion chamber from an external air source you can determine if the valves or rings are leaking and how badly Cylinder Leakdown Tester see Section 2 is a relatively simple inexpensive leakdown tester for small engines The tester includes a quick disconnect for attaching the adapter hose and a holding tool Leakdown Test Instructions 1 Run the engine for 3 5 minutes to warm it up 2 Remove the spark plug s and the air filter from engine 3 Rotate the crankshaft
265. s to what might be found inside the engine and the cause when it is disassembled Check for buildup of dirt and debris on the crankcase cooling fins grass screen and other external surfaces Dirt or debris on these areas are causes of higher operating temperatures and overheating Check for obvious fuel and oil leaks and damaged components Excessive oil leakage can indicate a clogged or improperly assembled breather worn damaged seals and gaskets or loose or improperly torqued fasteners Check the air cleaner cover and base for damage or indications of improper fit and seal Check the air cleaner element Look for holes tears cracked or damaged sealing surfaces or other damage that could allow unfiltered air into the engine Also note if the element is dirty or clogged These could indicate that the engine has been under serviced Check the carburetor throat for dirt Dirt in the throat is further indication that the air cleaner is not functioning properly Check the oil level Note if the oil level is within the operating range on the dipstick or if it is low or overfilled 3 3 Section 3 Troubleshooting 3 Check the condition of the oil Drain the oil into a container the oil should flow freely Check for metal chips and other foreign particles Sludge is a natural by product of combustion a small accumulation is normal Excessive sludge formation could indicate overri
266. sadjusted choke or throttle controls 6 Faulty spark plugs 7 Low compression 8 Faulty ACR mechanism equipped models 9 Weak spark 10 Fuel pump malfunction causing lack of fuel 11 Engine overheated cooling air circulation restricted 12 Quality of fuel 13 Flywheel key sheared 14 Intake system leak Engine Will Not Crank 1 PTO drive is engaged 2 Battery is discharged 3 Safety interlock switch is engaged 4 Loose or faulty wires or connections 5 Faulty key switch or ignition switch 6 Faulty electric starter or solenoid 7 Seized internal engine components Engine Runs But Misses 1 Dirt or water in the fuel system 2 Spark plug lead disconnected 3 Poor quality of fuel 4 Faulty spark plug s 5 Loose wires or connections that intermittently ground the ignition kill circuit 6 Engine overheated 7 Faulty ignition module or incorrect air gap 8 Carburetor adjusted incorrectly 9 SMART SPARK malfunction applicable models 3 2 Section 3 Troubleshooting Engine Will Not Idle 1 Dirt or water in the fuel system 2 Stale fuel and or gum in carburetor 3 Faulty spark plugs 4 Fuel supply inadequate 5 Idle fuel adjusting needle improperly set some models 6 Idle speed adjusting screw improperly set 7 Low compression 8 Restricted fuel tank cap vent 9 Engine overheated cooling system air circulation problem Engine Overheats 1 Air intake grass screen cooling fins or co
267. se Make sure to install the piston connecting rod and end cap into its appropriate cylinder bore as previously marked at disassembly Do not mix the end caps and connecting rods NOTE Proper orientation of the piston connecting rod assemblies inside the engine is extremely important Improper orientation can cause extensive wear or damage Be certain the pistons and connecting rods are assembled exactly as shown in Figure 11 8 1 Stagger the piston rings in the grooves until the end gaps are 120 apart The oil ring rails should also be staggered 2 Lubricate the cylinder bore piston and piston rings with engine oil Compress the rings using a piston ring compressor 3 Lubricate the crankshaft journals and connecting rod bearing surfaces with engine oil 4 Make sure the Fly stamping on the piston is facing towards the flywheel side of the engine Use a hammer with a rubber grip and gently tap the piston into the cylinder as shown in Figure 11 9 Be careful that the oil ring rails do not spring free between the bottom of the ring compressor and the top of the cylinder Install Crankshaft 1 Carefully slide the flywheel end of the crankshaft through the main bearing in the crankcase See Figure 11 7 Figure 11 8 Proper Piston Connecting Rod Orientation Cylinder 1 Cylinder 2 Figure 11 9 Installing Piston Assembly Using Ring Compressor Tool 5 Install the inner rod cap to the connecting r
268. sembly The oil pump is mounted inside the oil pan If service was required and the oil pump was removed refer to the assembly procedures under Oil Pump Assembly in Section 10 Determining Camshaft End Play 1 Install the shim removed during disassembly onto the camshaft 2 Position the camshaft end play checking tool on the camshaft See Figure 11 14 Governor Gear Assembly The governor gear assembly is located inside the oil pan If service was required and the governor was removed refer to the assembly procedures under Governor Gear Assembly in Section 10 Install Oil Seal in Oil Pan 1 Check to make sure that there are no nicks or burrs in the crankshaft bore of the oil pan 2 Apply a light coat of engine oil to the outside diameter of the oil seal 3 Drive the oil seal into the oil pan using a seal driver Make sure the oil seal is installed straight and true in the bore to the depth shown in Figures 11 15 and 11 16 Figure 11 15 Installing Oil Seal in Oil Pan Figure 11 16 Oil Seal Depth in Oil Pan 6 5 mm 0 255 in Oil Seal 11 6 Section 11 Reassembly 6 Install the ten hex flange screws securing the oil pan to the crankcase Torque the fasteners in the sequence shown in Figure 11 18 to 24 4 N m 216 in lb On some engines one of the ten mounting screws is plated The plated screw is typically installed in the 6 hole shown in Figure 11 18 Figure 11 19 Torquing
269. sing spring tension or improper starter disassembly can cause the sudden and potentially dangerous release of the spring Follow these instructions carefully to ensure personal safety and proper starter disassembly Make sure adequate face protection is worn by all persons in the area 1 Release spring tension and remove the handle and starter rope Refer to Rope Replacement steps 2 through 5 on page 7 1 2 Remove the center screw washer and pawl retainer See Figure 7 4 3 Remove the brake spring and brake washer See Figure 7 5 4 Carefully note the positions of the pawls and pawl springs before removing them Remove the pawls and pawl springs from the starter pulley 7 3 Section 7 Retractable Starter 7 Figure 7 6 Removing Pulley from Housing 8 Note the position of the spring and keeper assembly in the pulley See Figure 7 7 Remove the spring and keeper assembly from the pulley as a package WARNING Spring Under Tension Do not remove the spring from the keeper Severe personal injury could result from the sudden uncoiling of the spring Center Screw and Washer Pawl Retainer Housing Pulley Figure 7 4 Center Screw Washer and Pawl Retainer Figure 7 5 Brake Spring and Washer Pawls and Pawl Springs 5 Rotate the pulley clockwise 2 full turns This will ensure the spring is disengaged from the starter housing 6 Hold the pulley into the starter housing Invert the
270. sing which receives the backup washer See Figure 8 63 Figure 8 63 Installing Armature and Pivot Lever Figure 8 64 Installing Backup Washer and Grommet 8 Install the frame with the small notch forward onto the armature and drive end cap Align the notch with the corresponding section in the rubber grommet Install the drain tube in the rear cutout if it was removed previously See Figure 8 65 7 Install the backup washer followed by the rubber grommet into the matching recess of the drive end cap The molded recesses in the grommet should be out matching and aligned with those in the end cap See Figure 8 64 Figure 8 65 Installing Frame and Drain Tube 9 Install the flat thrust washer onto the commutator end of the armature shaft See Figure 8 66 8 37 8 Section 8 Electrical System and Components Figure 8 66 Installing Thrust Washer 10 Starter reassembly when replacing the Brushes Brush Holder Assembly a Hold the starter assembly vertically on the end housing and carefully position the assembled brush holder assembly with the supplied protective tube against the end of the commutator armature The mounting screw holes in the metal clips must be up out Slide the brush holder assembly down into place around the commutator and install the positive brush lead grommet in the cutout of the frame See Figure 8 67 The protective tube may be saved and used for future servicing
271. ssary lubricating oils off the piston and cylinder wall As raw fuel seeps down the cylinder wall the piston rings make metal to metal contact with the wall Scoring of the cylinder wall can also be caused by localized hot spots resulting from blocked cooling fins or from inadequate or contaminated lubrication If the cylinder bore is badly scored excessively worn tapered or out of round resizing is necessary Use an inside micrometer to determine the amount of wear refer to Specifications Tolerances and Special Torque Values in Section 1 then select the nearest suitable oversize of either 0 25 mm 0 010 in or 0 50 mm 0 020 in Resizing to one of these oversizes will allow usage of the available oversize piston and ring assemblies First resize using a boring bar then use the following procedures for honing the cylinder NOTE Some CV25 engines feature POWER BORE cylinders a special patented nickel silicone plating process for increased power superior oil control reduced exhaust emission and virtually permanent cylinder life POWER BORE cylinders cannot be resized or honed as described in the following procedure If a plated cylinder bore is damaged or out of specification use a new miniblock or short block to repair the engine Use the following procedures for crankcases with a cast iron sleeve Honing While most commercially available cylinder hones can be used with either portable drills or drill pre
272. ssenger car engines NOTE Using other than service class SG SH SJ or higher oil or extending oil change intervals longer than recommended can cause engine damage NOTE Synthetic oils meeting the listed classifications may be used with oil changes performed at the recommended intervals However to allow piston rings to properly seat a new or rebuilt engine should be operated for at least 50 hours using standard petroleum based oil before switching to synthetic oil A logo or symbol on oil containers identifies the API service class and SAE viscosity grade See Figure 6 1 Use of synthetic oil having 5W 20 or 5W 30 rating is acceptable up to 4 C 40 F Synthetic oils will provide better starting in extreme cold below 23 C 10 F 6 2 Section 6 Lubrication System Figure 6 2 Oil Fill Cap Dipstick 4 Remove dipstick and check oil level The level should be between the FULL and ADD marks If low add oil of the proper type up to the full mark Reinstall oil fill cap dipstick and thread tight Checking Oil Level The importance of checking and maintaining the proper oil level in the crankcase cannot be overemphasized Check oil BEFORE EACH USE as follows 1 Make sure the engine is stopped level and is cool so the oil has had time to drain into the sump 2 Clean the area around the oil fill cap dipstick before removing it This will help to keep dirt grass clippings etc out of the engi
273. sses the use of a low speed drill press is preferred as it facilitates more accurate alignment of the bore in relation to the crankshaft crossbore Honing is best accomplished at a drill speed of about 250 RPM and 60 strokes per minute After installing coarse stones in hone proceed as follows Figure 10 3 Cylinder Bore Crosshatch After Honing 10 4 Section 10 Inspection and Reconditioning Figure 10 4 Measuring Piston Diameter 2 Use an inside micrometer telescoping gauge or bore gauge and measure the cylinder bore Take the measurement approximately 63 5 mm 2 5 in below the top of the bore and perpendicular to the piston pin 3 Piston to bore clearance is the difference between the bore diameter and the piston diameter step 2 minus step 1 Flywheel Inspection Inspect the flywheel for cracks and the flywheel keyway for damage Replace flywheel if it is cracked Replace the flywheel the crankshaft and the key if the flywheel key is sheared or the keyway is damaged Inspect the ring gear for cracks or damage Kohler does not provide ring gears as a serviceable part Replace the flywheel if the ring gear is damaged Cylinder Head and Valves Inspection and Service After cleaning check the flatness of the cylinder head and the corresponding top surface of the crankcase using a surface plate or piece of glass and feeler gauge as shown in Figure 10 5 The maximum allowable out of flatness is 0 076 mm 0 00
274. st washer if so equipped from inside the starter frame 7 Remove the brush carrier assembly from the frame Style B starters Style A End Cap Brush Replacement 1 Remove the brush springs from the pockets in the brush holder See Figure 8 39 2 Remove the self tapping screws negative brushes and plastic brush holder 3 Remove the hex flange nut and fiber washer from the stud terminal Remove the stud terminal with the positive brushes and plastic insulating bushing from the end cap 4 Install the insulating bushing on the stud terminal of the new positive brushes Install the stud terminal into the commutator end cap Secure the stud with the fiber washer and hex flange screw 5 Install the brush holder new negative brushes and self tapping screws 6 Install the brush springs and brushes into the pockets in the brush holder Make sure the chamfered sides of the brushes are away from the brush springs 8 28 Section 8 Electrical System and Components NOTE Use a brush holder tool to keep the brushes in the pockets A brush holder tool can easily be made from thin sheet metal See Figure 8 40 Figure 8 40 Brush Holder Tool Style A End Cap Style B End Cap Brush Replacement Starters with Style B end caps have the brushes in a plastic carrier housing separate from the end cap Replacement brushes come preassembled in the carrier
275. sumes that all components are new or have been reconditioned and all component subassembly work has been completed The sequence may vary to accommodate options or special equipment Detailed procedures follow 1 Install flywheel end oil seal 2 Install governor cross shaft 3 Install crankshaft 4 Install connecting rods with pistons and rings 5 Install camshaft 6 Install oil pan assembly 7 Install stator and backing plates 8 Install flywheel 9 Install fan and grass screen 10 Install hydraulic lifters 11 Install cylinder heads 12 Install push rods and rocker arms 13 Install ignition modules 14 Install intake manifold 15 Install breather cover and inner baffles 16 Install blower housing and outer baffles 17 Install Oil SentryTM 18 Install control panel 19 Install valve covers 20 Install carburetor 21 Install external governor controls 22 Install throttle and choke controls 23 Install electric starter motor 24 Install fuel pump 25 Install air cleaner assembly see Section 4 26 Install muffler 27 Install oil cooler 28 Install oil filter and fill crankcase with oil 29 Connect spark plug leads Install Flywheel End Oil Seal 1 Make sure that the seal bore of the crankcase is clean and free of any nicks or burrs See Figure 11 1 Figure 11 1 Seal Bore of Crankcase 2 Apply a light coat of engine oil to the outside diameter of the oil seal 3 Drive the oil s
276. sure the ignition system governor system exhaust system and throttle and choke controls are operating properly If the engine is hard starting runs roughly or stalls at low idle speed it may be necessary to service the carburetor Troubleshooting Carburetor Related Causes Condition Possible Cause Probable Remedy 1 Low idle fuel mixture speed improperly adjusted Adjust the low idle speed screw then adjust the low idle fuel needle 1 Engine starts hard runs roughly or stalls at idle speed 2 Engine runs rich indicated by black sooty exhaust smoke misfiring loss of speed and power governor hunting or excessive throttle opening 2a Clogged air cleaner Clean or replace b Choke partially closed during operation Check the choke lever linkage to ensure choke is operating properly c Low idle fuel mixture is improperly adjusted Adjust low idle fuel needle d Float level too high Separate fuel bowl from carburetor body Free if stuck or replace float e Dirt under the fuel inlet needle Remove needle clean needle and seat and blow with compressed air f Bowl vent or air bleeds plugged Remove low idle fuel adjusting needle Clean vent ports and air bleeds Blow out all passages with compressed air g Leaky cracked or damaged float Submerge float to check for leaks 3 Engine runs lean indicated by misfiring loss of speed and power governor hunting or excessive throttle opening
277. t Cleaning Solvents can cause severe injury or death Use only in well ventilated areas away from ignition sources WARNING 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 Electrical Shock Never touch electrical wires or components while the engine is running They can be sources of electrical shock 1 3 Section 1 Safety and General Information 1 Engine Identification Numbers When ordering parts or in any communication involving an engine always give the Model Specification and Serial Numbers including letter suffixes if there are any The engine identification numbers appear on a decal or decals affixed to the engine shrouding See Figure 1 1 An explanation of these numbers is shown in Figure 1 2 Figure 1 1 Engine Identification Decal Location Figure 1 2 Explanation of Engine Identification Numbers A Model No Version Code S Electric Start C V 18 S Command Engine Vertical Crankshaft Horsepower 17 17 HP 18 18 HP 20 20 HP 22 22 HP 23 23 HP 25 25 HP 26 26 HP Numerical Designation 730 740 745 750 or Identification Decal Variation of Basic Engine B Spec No 61500 Engine Model Code Code Model 72 CV17 61 CV18 6
278. t interference angle where the maximum pressure occurs on the outside diameters of the valve face and seat Figure 10 7 Typical Valve Seat Cutter Lapping Valves Reground or new valves must be lapped in to provide proper fit Use a hand valve grinder with a suction cup for final lapping Lightly coat the valve face with a fine grade of grinding compound then rotate the valve on its seat with the grinder Continue grinding until a smooth surface is obtained on the seat and on the valve face Thoroughly clean the cylinder head in soap and hot water to remove all traces of grinding compound After drying the cylinder head apply a light coating of SAE 10 oil to prevent rusting Intake Valve Stem Seal These engines use valve stem seals on the intake valves Always use a new seal when the valves are removed from the cylinder head The seals should also be replaced if deteriorated or damaged in any way Never reuse an old seal Pistons and Rings Inspection Scuffing and scoring of pistons and cylinder walls occurs when internal engine temperatures approach the welding point of the piston Temperatures high enough to do this are created by friction which is usually attributed to improper lubrication and or overheating of the engine Normally very little wear takes place in the piston boss piston pin area If the original piston and connecting rod can be reused after new rings are installed the original pin can also be reused bu
279. t Assembly 12 Hold the carburetor body so the float assembly hangs vertically and rests lightly against the fuel inlet needle The inlet needle should be fully seated but the center pin of the needle on retainer clip end should not be depressed Check the float height adjustment NOTE The inlet needle center pin is spring loaded Make sure the float assembly rests against the fuel inlet needle without depressing the center pin 13 The correct float height adjustment is 12 0 mm 0 472 in measured from the float bottom to the body of the carburetor See Figure 5 25 Adjust the float height by carefully bending the metal tang of the float 5 17 Section 5 Fuel System and Governor 5 Figure 5 26 Installing Fuel Bowl O Rings 15 Install the fuel bowl onto the carburetor Secure with the four original screws Torque the screws to 2 5 0 3 N m 23 2 6 in lb Reattach the accelerator pump hose if so equipped and secure with the clip See Figure 5 27 14 When the proper float height is obtained carefully install the new O Rings for the fuel bowl and the accelerator pump transfer passage if so equipped See Figure 5 26 Figure 5 27 Installing Fuel Bowl 16 Install the new cover gasket and top cover on the carburetor Secure with the two large head screws and attach the ground lead if equipped with a fuel solenoid to the original screw location Torque the top cover screws to 2 5 0 3 N m 2
280. t being replaced position the brushes in their pockets in the carrier Move them to the retracted position and install carton staples to retain them See Figure 8 42 5 Align the terminal stud block with the notch in the starter frame and slide the brush carrier assembly into the frame The commutator will push the carton staples out as the brush assembly is installed Position the end cap over the brush assembly so the holes for the thru bolts are aligned with those in the brush carrier 8 29 8 Section 8 Electrical System and Components Figure 8 42 Style B Commutator End Cap with Brushes 6 Install the thru bolts and tighten securely 7 Lubricate the drive shaft with Kohler starter drive lubricant see Section 2 Install the drive components following the instructions for servicing the starter drive Solenoid Shift Electric Starters The following subsection covers the solenoid shift electric starters Much of the information in the proceeding subsection relates to this type starter also so it is not repeated here A Nippondenso or Delco Remy solenoid shift starter may be used The Nippondenso starter is covered first and the Delco Remy starter servicing follows Operation Solenoid Shift Starter When power is applied to the starter the electric solenoid moves the drive pinion out onto the drive shaft and into mesh with the flywheel ring gear When the pinion reaches the end of the drive shaft
281. t low speeds the engine operates only on the slow circuit As a metered amount of air is drawn through the slow air bleed jet fuel is drawn through the main jet and further metered through the slow jet Air and fuel are mixed in the body of the slow jet and exit to the transfer port From the transfer port this air fuel mixture is delivered to the idle progression chamber From the idle progression chamber the air fuel mixture is metered through the idle port passage At low idle when the vacuum signal is weak the air fuel mixture is controlled by the setting of the idle fuel adjusting screw This mixture is then mixed with the main body of air and delivered to the engine As the throttle plate opening increases greater amounts of air fuel mixture are drawn in through the fixed and metered idle progression holes As the throttle plate opens further the vacuum signal becomes great enough so the main circuit begins to work Low Idle Mixture Screw Keihin Carburetors Only Idle Limiter Jet Idle Port Spring 5 6 Section 5 Fuel System and Governor Figure 5 4 Main Circuit Check Valve Spring Outlet Check Valve Leak Jet Adjustment Screw Diaphragm Spring Pump Diaphragm Inlet Check Valve ACCELERATOR PUMP ASSEMBLY Some Carburetors Fuel Shut Off Solenoid with Main Jet Main Jet Main Nozzle Throttle Valve Choke Valve Main Air Bleed Jet Accelerator Pump Nozzle Bowl Vent Fuel Inlet Float Valve Seat
282. t new piston pin retainers are required The piston pin is included as part of the piston assembly if the pin boss in the piston or the pin are worn or damaged a new piston assembly is required Valve Seat Cutter Pilot 10 9 Section 10 Inspection and Reconditioning 10 Ring failure is usually indicated by excessive oil consumption and blue exhaust smoke When rings fail oil is allowed to enter the combustion chamber where it is burned along with the fuel High oil consumption can also occur when the piston ring end gap is incorrect because the ring cannot properly conform to the 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 the fuel charge ignites spontaneously from heat and pressure shortly after ignition This creates two flame fronts which meet and explode to create extreme hammering pressures on a specific area of the piston Detonation generally occurs from using low octane fuels Preignition or ignition of the fuel charge before the timed spark can cause damage similar to detonation Preignition damage is
283. t the starter motor NOTE If the engine develops sufficient speed to disengage the starter but does not keep running a false start the engine rotation must be allowed to come to a complete stop before attempting to restart the engine If the starter is engaged while the flywheel is rotating the starter pinion and flywheel ring gear may clash resulting in damage to the starter Problem Possible Fault Correction 1 Check the specific gravity of battery If low recharge or replace battery as necessary 1 Clean corroded connections and tighten loose connections 2 Replace wires in poor condition and with frayed or broken insulation 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 8 39 and 8 40 1 Check the specific gravity of battery If low recharge or replace battery as necessary 1 Check for excessively dirty or worn brushes and commutator Clean using a coarse cloth not emery cloth 2 Replace brushes if excessively or unevenly worn 1 Make sure the clutch or transmission is disengaged or placed in neutral This is especially important on equipment with hydrostatic drive The transmission must be exactly in neutral to prevent resistance which could keep the engine from starting 2 Check for seized engine components such as the bearings connecting rod and pist
284. ted to the governor lever and the throttle lever on the carburetor See Figure 11 71 Figure 11 67 Installing Carburetor Throttle Linkage and Governor Lever Figure 11 68 Installing Two Barrel Carburetor Figure 11 69 Installing External Governor Controls Install External Governor Controls 1 Install the governor lever onto the governor cross shaft See Figure 11 70 Figure 11 71 Installing External Governor Controls One Barrel Carburetor Two Barrel Carburetor Models Move the control panel into position on the blower housing and connect the choke linkage into the bushing lever from the backside Make certain that the control shaft offset is back and towards the 2 side cylinder See Figure 11 72 Connect the throttle linkage and spring to the governor lever See Figure 11 73 11 21 Section 11 Reassembly 11 Figure 11 73 Throttle Linkage Details 3 Move the governor lever toward the carburetor as far as it will go wide open throttle and hold in position 4 Insert a nail into the hole on the cross shaft and rotate the shaft counterclockwise as far as it will turn then torque the hex nut to 6 8 N m 60 in lb 5 Reconnect the lead wire to the fuel shut off solenoid if so equipped 6 Install the lower support control bracket if equipped with a control panel See Figure 11 74 Figure 11 72 Choke Linkage Details Two Barrel Models Figure 11 75 Installing Control Panel 8 Assemble
285. tem and Components Kill Switch or Off Position of Key Switch Ignition Modules Spark Plug Magnet Flywheel 0 28 0 33 mm 0 011 0 013 in Air Gap The timing of the spark is controlled by the location of the flywheel magnet group as referenced to engine top dead center Figure 8 4 Capacitive Discharge Fixed Timing Ignition System L1 D1 C1 T1 P S Spark Plug L2 SCS Figure 8 5 Capacitive Discharge Ignition Module Schematic Operation As the flywheel rotates the magnet grouping passes the input coil L1 The corresponding magnetic field induces energy into the input coil L1 The resultant pulse is rectified by D1 and charges capacitor C1 As the magnet assembly completes its pass it activates the triggering device L2 which causes the semiconductor switch SCS to turn on With the device switch ON the charging capacitor C1 is directly connected across the primary P of the output transformer T1 As the capacitor discharges the current initiates a fast rising flux field in the transformer core A high voltage pulse is generated from this action into the secondary winding of the transformer This pulse is delivered to the spark plug gap Ionization of the gap occurs resulting in an arc at the plug electrodes This spark ignites the fuel air mixture in the combustion chamber 8 6 Section 8 Electrical System and Components B Capacitive Discharge with Electronic S
286. tem errors than an actual component Refer to the Troubleshooting Electrical section for additional information Battery Charging System EFI engines are equipped with either a 15 or 25 amp charging system to accommodate the combined electrical demands of the ignition system and the specific application Charging system troubleshooting information is provided in Section 8 Fuel Components Fuel Pump Internal External Figure 5B 21 24 Pin MSE 1 0 Plastic Cased ECU Connector Figure 5B 22 32 Pin MSE 1 1 Plastic Cased ECU Connector Figure 5B 23 Fuel Pump Styles General An electric fuel pump is used to transfer fuel in the EFI system Depending on the application the pump may be inside the fuel tank or in the fuel line near the tank The pumps are rated for a minimum output of 25 liters per hour at 39 psi The pumps have an internal 60 micron filter In addition the in tank style pumps will have a pre filter attached to the inlet In line pump systems may also have a filter between the tank and the pump on the pickup low pressure side The final fuel filter is covered separately on page 5B 21 When the key switch is turned on and all safety switch requirements are met the ECU through the relay activates the fuel pump which pressurizes the system for start up If the key switch is not promptly turned to the start position the engine fails to start or the engine is stopped wi
287. ter from loose end of B lead to negative terminal of battery With engine running at 3600 RPM read voltage on voltmeter If voltage is 13 8 volts or more place a minimum load of 5 amps on battery to reduce voltage Observe ammeter NOTE Turn on lights if 60 watts or more Or place a 2 5 1 If voltage is 13 8 14 7 and charge rate increases when load is applied the charging system is OK and battery was fully charged If voltage is less than 13 8 or charge rate does not increase when load is applied test stator Tests 2 and 3 If the voltage is low and does not increase and there is no charging amperage output disconnect and reconnect the rectifier regulator plug and retest a If the ammeter shows charge for a short time but then drops back to zero the rectifier regulator is functioning correctly but the battery is faulty Replace the battery b If no amperage charge rate appears during the retest go to step 2 Troubleshooting Guide 15 20 25 Amp Battery Charging Systems When problems occur in keeping the battery charged or the battery charges at too high a rate the problem can usually be found somewhere in the charging system or with the battery NOTE Always zero ohmmeter on each scale before testing to ensure accurate readings Voltage tests should be made with the engine running at 3600 RPM no load The battery must be good and fully charged 2 Remove connector from rectifier regulator With engi
288. terminal Pink tester lead to the short yellow or pink module lead Brown tester lead with black band or terminal to the short brown module lead NOTE Some modules contain two black ground leads with one containing a white stripe Do not connect to the black white lead with the bullet connector or a Fail test result will occur regardless of actual condition Caution Do not allow alligator clip leads to touch each other 2 Recheck the SAM part number noting the last two digits Refer to the table below or on the tester faceplate to determine the test number to be used To Test Using 25 761 40 S Tester DSAM ASAM Test Procedure NOTE The SAM must be at room temperature when tested Disconnect all of the SAM leads isolating it from the main wiring harness and the ignition module s Testing may be performed with the module mounted or loose The figures show the part removed from the engine for clarity See Figure 8 14 ASAM Module Test Connections DSAM Module Test Connections M A S o N tr a P 8 1 4 8 5 4 2 7 2 4 8 5 4 2 9 1 4 8 5 4 2 8 3 4 8 5 4 2 9 3 4 8 5 4 2 o N t s e T 5 6 7 8 M A S o N tr a P 2 1 4 8 5 2 1 9 0 4 8 5 4 2 0 1 4 8 5 4 2 0 3 4 8 5 4 2 1 3 4 8 5 4 2 3 3 4 8 5 4 2 4 3 4 8 5 4 2 2 3 4 8 5 4 2 o N t s e T 1 2 3 4 3 Depress the tester button re
289. tery and also unplug the harness from the ECU before performing any welding on the equipment Electrical Components Electronic Control Unit ECU Figure 5B 1 24 Pin MSE 1 0 Plastic Cased ECU Figure 5B 2 32 Pin MSE 1 1 Plastic Cased ECU 5B 5 Section 5B EFI Fuel System 5B Two different ECU styles have been used in CV EFI production Each has a plastic case but they differ in having a 24 pin or 32 pin connector block and are identified as MSE 1 0 or MSE 1 1 respectively See Figures 5B 1 and 5B 2 Basic function and operating control remains the same between the two however due to differences in the internal circuitry as well as the wiring harness the ECU s are not interchangeable Certain service troubleshooting procedures will also differ so where applicable they are covered individually as 24 Pin MSE 1 0 Plastic Cased ECU or 32 Pin MSE 1 1 Plastic Cased ECU General The ECU is the brain or central processing computer of the entire EFI system During operation sensors continuously gather data which is relayed through the wiring harness to input circuits within the ECU Signals to the ECU include ignition on off crankshaft position and speed RPM throttle position oil temperature exhaust oxygen levels and battery voltage The ECU compares the input signals to the programmed maps in its memory to determine the appropriate fuel and spark requirements for the immediate oper
290. th the key switch on as in the case of an accident the ECU switches off the 5B 19 Section 5B EFI Fuel System 5B pump preventing the continued delivery of fuel In this situation the MIL will go on but it will go back off after 4 cranking revolutions if system function is OK Once the engine is running the fuel pump remains on Service The fuel pumps are non serviceable and must be replaced if determined to be faulty If a fuel delivery problem is suspected make certain the pump is being activated through the relay all electrical connections are properly secured the fuses are good and a minimum of 7 0 volts is being supplied If during cranking voltage drops below 7 0 volts a reduction of fuel pressure may occur resulting in a lean starting condition If required testing of the fuel pump and relay may be conducted 1 Connect the black hose of Pressure Tester part of EFI Service Kit see Section 2 to the test valve in the fuel rail Route the clear hose into a portable gasoline container or the equipment fuel tank 2 Turn on the key switch to activate the pump and check the system pressure on the gauge If system pressure of 39 psi 3 is observed the relay fuel pump and regulator are working properly Turn key switch off and depress the valve button on the tester to relieve the system pressure a If the pressure is too high and the regulator is outside the tank just down line from the pump chec
291. the armature shaft Do not reuse the retainer Brush Replacement The brushes in the starter are part of the starter frame Brush kit Kohler Part No 52 221 01 S contains four replacement brushes and springs If replacement is necessary all four brushes should be replaced 1 Remove the brushes from the brush holder and remove the brush holder from the frame 2 Cut the brush lead wire at the edge of the post with a pair of nippers 3 File off any burrs on the post 4 The replacement brushes have a solid portion which should be crimped on the post 5 Solder the crimped portion to the post 6 Replace the brush holder in the frame and place the brushes in the brush holder Reinstall the springs Starter Service Every 500 hours of operation or annually whichever comes first solenoid shift starters must be disassembled cleaned and relubricated Apply starter lubricant see Section 2 to the lever and shaft Failure to do so could result in an accumulation of dirt or debris that might prevent the engine from starting and could cause damage to the starter or the flywheel Service may be necessary more frequently under dusty or dirty conditions Starter Reassembly 1 Insert the rear stop collar on the armature shaft 2 Place the retainer in the groove on the armature shaft NOTE Always use a new retainer Tighten the retainer in the groove to secure 3 Fit the front stop collar over the shaft and bring the
292. the injectors are operating 1 With the engine running at idle feel for operational vibration indicating that they are opening and closing 2 When temperatures prohibit touching listen for a buzzing or clicking sound with a screwdriver or mechanic s stethoscope see Figure 5B 17 5B 15 Section 5B EFI Fuel System 5B Figure 5B 18 Volt Noid Light 1 Disconnect the electrical connector from both injectors Plug a 12 volt noid light part of EFI Service Kit see Section 2 into one connector 2 Make sure all safety switch requirements are met Crank the engine and check for flashing of the test light Repeat test at other connector a If flashing occurs use an ohmmeter Rx1 scale and check the resistance of each injector across the two terminals Proper resistance is 12 20 If injector resistance is correct check whether the connector and injector terminals are making a good connection If the resistance is not correct replace the injector following steps 1 8 and 13 16 below b If no flashing occurs reattach the connectors to both injectors Disconnect the main harness connector from the ECU and the connector from the relay Set the ohmmeter to the Rx1 scale and check the injector circuit resistance as follows 24 Pin MSE 1 0 Plastic Cased ECU Check the resistance between relay terminal 87 and pin 16 in the main connector Then check the resistance between relay terminal 87 a
293. the reeds and creates a low vacuum in the lower crankcase The combination of low pressure above and low vacuum below forces any accumulated oil out of the 2 head area into the crankcase On the 1 bank you have atmospheric pressure above and vacuum below again drawing any oil toward the crankcase 2 0 mm 0 0787 in Governor Cross Shaft Seal Figure 10 21 Installing Cross Shaft Oil Seal 11 1 Section 11 Reassembly 11 Section 11 Reassembly General NOTE Make sure the engine is assembled using all specified torque values tightening sequences and clearances Failure to observe specifications could cause severe engine wear or damage Always use new gaskets Apply a small amount of oil to the threads of critical fasteners before assembly unless a Sealant or Loctite is specified or pre applied Make sure all traces of any cleaner are removed before the engine is assembled and placed into operation Even small amounts of these cleaners can quickly break down the lubricating properties of engine oil Check the oil pan crankcase cylinder heads and valve covers to be certain that all old sealing material has been removed Use gasket remover lacquer thinner or paint remover to remove any remaining traces Clean the surfaces with isopropyl alcohol acetone lacquer thinner or electrical contact cleaner Typical Reassembly Sequence The following sequence is suggested for complete engine reassembly This procedure as
294. the retracted position by the anti drift spring Starter Drive Service Every 500 hours of operation or annually whichever occurs first clean and lubricate the splines on the starter drive shaft If the drive pinion is worn or has chipped or broken teeth it must be replaced See Figure 8 34 It is not necessary to completely disassemble the starter to service the drive components Style A Drive Service 1 Remove the starter from the engine and remove the dust cover 2 Hold the drive pinion in a vice with soft jaws when removing or installing the stop nut The armature will rotate with the nut until the drive pinion stops against internal spacers NOTE Do not over tighten the vise as this can distort the drive pinion 3 Remove the stop nut stop gear spacer anti drift spring dust cover spacer and drive pinion 4 Clean the splines on the drive shaft thoroughly with solvent Dry the splines thoroughly 5 Apply a small amount of Kohler electric starter drive lubricant see Section 2 to the splines The use of other lubricants may cause the drive pinion to stick or bind 6 Apply a small amount of Loctite No 271 to the stop nut threads 7 Install the drive pinion dust cover spacer anti drift spring stop gear spacer and stop nut Torque the stop nut to 17 0 19 2 N m 150 170 in lb Reinstall the dust cover Style A Style B Style A Style
295. the throttle control shaft to the control bracket 9 Assemble the choke control to the control bracket Figure 11 74 Installing Lower Support Control Bracket 7 Secure the control panel to the blower housing with the two screws Models without a Heavy Duty Air Cleaner See Figure 11 75 Bushing Lever Choke Linkage 11 22 Section 11 Reassembly Figure 11 76 Connecting Governor Spring to Governor Lever Install Throttle and Choke Controls 1 One Barrel Carburetor Models Connect the choke linkage to the carburetor and choke actuator lever 10 Connect the Oil Sentry Indicator light wires Attach governor spring to governor lever See Figure 11 76 and appropriate charts on pages 11 23 through 11 25 Figure 11 77 Standard Control Bracket 2 One Barrel Carburetor Models Install the standard throttle control bracket and the air cleaner support bracket if used to the cylinder heads using the four hex flange screws Torque the screws to 10 7 N m 95 in lb into new holes or 7 3 N m 65 in lb into used holes 11 23 Section 11 Reassembly 11 3 Connect the governor spring from the throttle control bracket to the appropriate hole in the governor lever as indicated in the applicable chart Note that hole positions are counted from the pivot point of the governor lever Governor Lever Governor Spring High Idle RPM Hole No Color Code 3801 4000 6 Clear 3601 3800 5 Clear 3451 3
296. to remove lifters Mark the lifters by location as either intake or exhaust and cylinder 1 or 2 Hydraulic lifters should always be reinstalled in the same position See Figure 9 44 Figure 9 44 Removing Hydraulic Lifters Disassemble Cylinder Heads 1 Remove the two hex flange screws rocker arm pivots and rocker arms from the cylinder head See Figure 9 45 Hydraulic Lifter Tool 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 as the cylinder heads may have different machining unique to each fastening method 1 Remove the four hex flange screws or hex nuts and washers securing each cylinder head See Figure 9 42 Discard the screws or nuts and washers once removed Do not reuse Studs if present should only be removed if damaged or if cylinder reconditioning is necessary Once removed they must be replaced 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 Figure 9 42 Removing Cylinder Head Fasteners 3 Carefully remove the push rods cylinder heads and head gaskets See Figure 9 43 Hex Flange Screws Hex Flange Nuts and Washers 9 13 Section 9 Disassembly 9 Figure 9 45 Removing Rocker Arm 2 Compress the valve springs using a valve spring compressor
297. tor outer surface The mica insulation must be lower than the commutator bars undercut to ensure proper operation of the commutator See Figure 8 57 Figure 8 58 Checking Armature 3 Check for continuity between the armature coil segments and the commutator segments See Figure 8 58 There should be no continuity If continuity exists between any two the armature is bad 4 Check the armature windings insulation for shorting Shift Fork Check that the shift fork is complete and the pivot and contact areas are not excessively worn cracked or broken Figure 8 57 Commutator Mica Inspection 2 Use an ohmmeter set to the Rx1 scale Touch the probes between two different segments of the commutator and check for continuity See Figure 8 58 Test all the segments Continuity must exist between all or the armature is bad Wear limit length 7 6 mm 0 300 in Commutator O D Mica Insulation Continuity Check Armature Coil Insulation Check Inspection Drive Pinion Check and inspect the following areas a The pinion teeth for abnormal wear or damage b The surface between the pinion and the clutch mechanism for nicks or irregularities which could cause seal damage c Check the drive clutch by holding the clutch housing and rotating the pinion The pinion should rotate in one direction only Brushes and Springs Inspect both the springs and brushes for wear fatigue or damage Measure the lengt
298. try will either shut off the engine or activate a warning signal depending on the application The pressure switch is designed to break contact as the oil pressure increases above 3 5 psi and make contact as the oil pressure decreases below 3 5 psi On stationary or unattended applications pumps generators etc the pressure switch can be used to ground the ignition module to stop the engine On vehicular applications lawn tractors mowers etc the pressure switch can only be used to activate a low oil warning light or signal NOTE Make sure the oil level is checked before each use and is maintained up to the FULL 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 9 Oil Sentry 7 1 Section 7 Retractable Starter 7 Section 7 Retractable Starter WARNING Spring Under Tension Retractable starters contain a powerful recoil spring that is under tension Always wear safety goggles when servicing retractable starters and carefully follow instructions in this section for relieving spring tension Handle with Rope Retainer Drive Cup Starter Housing Rope Pawl Springs Pawls Pawl Retainer Plain Washer Center Screw Brake Spring Brake Washer Pulley Spring and Keeper Hex Flange Screws Figure 7 1 Retractable Starter Exploded View To Remove
299. uit At high speeds loads the engine operates on the main circuit As a metered amount of air is drawn through the four air jets fuel is drawn through the main jets The air and fuel are mixed in the main nozzles and then enter the main body of airflow where further mixing of the fuel and air occurs This mixture is then delivered to the combustion chamber The carburetor has a fixed main circuit no adjustment is possible 5 21 Section 5 Fuel System and Governor 5 Adjustment NOTE Carburetor adjustments should be made only after the engine has warmed up The carburetor is designed to deliver the correct fuel to air mixture to the engine under all operating conditions The main fuel jet is calibrated at the factory and is not adjustable The idle fuel adjusting needle is also set at the factory and normally does not need adjustment Depending on model and application engines may also be equipped with a Governed Idle System If equipped with a Governed Idle System refer to Models with Governed Idle System when performing any carburetor adjustment as an additional step to the listed adjustment procedure s is required NOTE Engines operating at altitudes above approximately 1500 m 5000 ft may require a special high altitude main jet Refer to High Altitude Operation If however the engine is hard starting or does not operate properly it may be necessary to adjust or serv
300. un engine for about 5 minutes With the engine running disconnect the oxygen sensor lead from the wiring harness Set VOA meter for DC volts and connect the red lead to the disconnected sensor lead and the black lead to the sensor shell Look for a voltage reading from 0 2 v 1 0 v a If voltage is in the specified range go to Step 2 b If voltage is not in the specified range reconnect the oxygen sensor lead With the lead connected probe or connect the sensor connection with the red VOA meter lead Attach the black VOA meter lead to a good ground location Start and run the engine at 3 4 throttle and note the voltage reading being signaled by the oxygen sensor The reading should cycle between 0 2 v and 1 0 v which indicates the oxygen sensor is functioning normally and fuel delivery is within prescribed parameters If the voltage readings show a steady decline rev the engine and check the indicated reading again If the voltage momentarily increases and then again declines without cycling the engine may be running lean due to incorrect TPS initialization Shut off the engine perform TPS initialization and then repeat the test If TPS initialization cannot be achieved perform step c c Replace the oxygen sensor see next page Run the engine long enough to bring the new sensor up to temperature and repeat the output test from step 1 The cycling voltage from 0 2 to 1 0 v should be indicated 2 Move the black voltm
301. unted to the blower housing remove the two oil cooler mounting screws 7 Remove the blower housing mounting screws Note the location of the plated silver screw attaching the rectifier regulator ground lead Remove the blower housing 8 Thoroughly clean the area around and including the throttle body manifold and the injectors 9 Disconnect the throttle linkage and damper spring from the throttle lever Disconnect the TPS lead from the harness Check For Leaks 5B 17 Section 5B EFI Fuel System 5B Ignition System General A high voltage solid state battery ignition system is used with the EFI system The ECU controls the ignition output and timing through transistorized control of the primary current delivered to the coils Based on input from the speed sensor the ECU determines the correct firing point for the speed at which the engine is running At the proper instant it releases the flow of primary current to the coil The primary current induces high voltage in the coil secondary which is then delivered to the spark plug Each coil fires every revolution but every other spark is wasted Service Except for removing the spark plug lead by unscrewing it from the secondary tower see Figure 5B 20 no coil servicing is possible If a coil is determined to be faulty replacement is necessary An ohmmeter may be used to test the wiring and coil windings Figure 5B 20 Ignition Coil NOTE Do not ground
302. ure Regulator Details Service Depending on the application the regulator may be located in the fuel tank along with the fuel pump or outside the tank just down line from the pump The regulator is a sealed non serviceable assembly If it is faulty it must be separated from the base holder assembly and replaced as follows 1 Shut engine off make sure engine is cool and disconnect the negative battery cable 2 Depressurize fuel system through test valve in fuel rail see fuel warning on page 5B 2 3 Access the regulator assembly as required and clean any dirt or foreign material away from the area 4 External Regulator Based upon the style of regulator used See Figure 5B 27 General The fuel pressure regulator assembly maintains the required operating system pressure of 39 psi 3 A rubber fiber diaphragm see Figure 5B 26 divides the regulator into two separate sections the fuel chamber and the pressure regulating chamber The pressure regulating spring presses against the valve holder part of the diaphragm pressing the valve against the valve seat The combination of atmospheric pressure and regulating spring tension equals the desired operating pressure Any time the fuel pressure against the bottom of the diaphragm exceeds the desired top pressure the valve opens relieving the excess pressure returning the excess fuel back to the tank Figure 5B 28 Internal In Tank Regulator and Base Holder
303. ust the Low Idle Speed RPM to the specified setting Figure 5 39 Keihin Two Barrel Carburetor Carburetor Adjustment Low Idle Speed RPM Adjustment 1 Low Idle Speed RPM Setting Place the throttle control into the idle or slow position Set the low idle speed to 1200 RPM 75 RPM by turning the low idle speed adjusting screw in or out Check the speed using a tachometer Low Idle Fuel Adjusters with Limiters Low Idle Speed RPM Adjustment Screw Fuel Solenoid Bowl Drain Screw 5 22 Section 5 Fuel System and Governor Figure 5 41 Governed Idle Spring Location Figure 5 40 Optimum Low Idle Fuel Settings Models with Governed Idle System An optional governed idle control system is supplied on some engines The purpose of this system is to maintain a desired idle speed regardless of ambient conditions temperature parasitic load etc that may change Engines with this feature contain a small secondary spring connected between the governor lever and the lower adjustment tab of the main bracket See Figure 5 41 The system requires an additional procedure for setting the idle speed If speed adjustments are required proceed as follows 1 Make any necessary speed or control adjustments following the appropriate instructions covered in this section 2 Move the throttle control to the idle position Hold the governor lever away from the carburetor or hold the throttle lever so it is tight
304. wer housing and baffles See Figures 11 57 through 11 59 Figure 11 61 Tightening Short Screws for Outer Baffles 4 Tighten all of the shrouding fasteners Torque the blower housing screws to 6 2 N m 55 in lb in a new hole or to 4 0 N m 35 in lb in a used hole Torque the shorter M5 side baffle screws to 4 0 N m 35 in lb See Figure 11 61 Torque the M5 side baffle screws into cylinder head to 6 2 N m 55 in lb in a new hole or to 4 0 N m 35 in lb in a used hole Torque the two lower M6 baffle mounting screws to 10 7 N m 95 in lb in a new hole or to 7 3 N m 65 in lb in a used hole 5 If the engine had a plastic flywheel that overlaps the blower housing reinstall it now Torque the mounting screws to 4 0 N m 36 in lb For a metal screen apply Loctite No 242 to screw threads and torque the screws to 9 9 N m 88 in lb 6 Torque the four breather cover screws to 7 3 N m 65 in lb in the sequence shown in Figure 11 62 Figure 11 60 Tightening Outer Baffle Front Screws Figure 11 62 Breather Cover Fastener Torque Sequence 1 2 3 4 11 18 Section 11 Reassembly Figure 11 64 Rectifier Regulator Ground Details 2 Install the B terminal lead into the center position of the rectifier regulator plug and connect the plug to the rectifier regulator See Figure 11 65 Figure 11 63 Oil Sentry Switch Some Models Install Control Panel If So Equipped
305. wire bracket if used Secure with the four hex flange screws See Figures 11 21 and 11 22 Torque the screws to 7 3 N m 65 in lb Figure 11 21 Route Stator Leads in Groove Figure 11 24 Carefully Align Keyway to Key 1 Install the woodruff key into the keyway of the crankshaft Make sure that the key is properly seated and parallel with the shaft taper 11 8 Section 11 Reassembly Figure 11 26 Installing Fan 3 If the engine has a plastic grass screen snap the screen onto the fan See Figure 11 27 Due to the possibility of damaging the posts during removal install the retainers on different posts from which they were removed Start the retainers by hand then push them down with a 13 mm 1 2 socket until they lock If the engine has a metal screen it will be installed later NOTE Make sure the flywheel key is installed properly in the keyway The flywheel can become cracked or damaged if the key is not properly installed 2 Install the flywheel onto the crankshaft being careful not to shift the woodruff key See Figure 11 24 3 Install the hex flange screw and washer 4 Use a flywheel strap wrench or holding tool to hold the flywheel Torque the hex flange screw securing the flywheel to the crankshaft to 66 4 N m 49 ft lb See Figure 11 25 Figure 11 25 Installing and Torquing Flywheel Fastener Install Fan and Grass Screen 1 Install the fan onto the flywheel using the four hex fl
306. xygen Sensor 5 Code 32 Oxygen Sensor 6 Code 33 Fuel System temporary adaptation factor 7 Code 34 Fuel System permanent adaptation factor 8 Code 42 Engine Oil Temperature Sensor 9 Code 43 TPS Auto Learn Initialization Function Below Min Limit 32 Pin MSE 1 1 Plastic Cased ECU only 10 Code 44 TPS Auto Learn Initialization Function Above Max Limit 32 Pin MSE 1 1 Plastic Cased ECU only 11 Code 51 Injector 1 32 Pin MSE 1 1 Plastic Cased ECU only 12 Code 52 Injector 2 32 Pin MSE 1 1 Plastic Cased ECU only 13 Code 55 MIL Light 32 Pin MSE 1 1 Plastic Cased ECU only 14 Code 56 Pump Relay 32 Pin MSE 1 1 Plastic Cased ECU only 15 Code 61 End of Fault Blink Code Transmission Diagnostic Aid 3 RUN ON MIL remains on while engine is running Possible causes 1 Fault codes which turn on MIL when engine is running a Code 21 Engine Speed Synchronization b Code 22 Throttle Position Sensor TPS c Code 23 Engine Control Unit ECU d Code 31 Oxygen Sensor shorted e Code 34 Fuel System permanent adaptation at limit f Code 42 Engine Oil Temperature Sensor g Code 43 TPS Auto Learn Initialization Function Below Min Limit 32 Pin MSE 1 1 Plastic Cased ECU only h Code 44 TPS Auto Learn Initialization Function Above Max Limit 32 Pin MSE 1 1 Plastic Cased
307. y retracted the solenoid should be replaced Figure 8 76 Testing Hold In Coil Function Test 8 40 Section 8 Electrical System and Components Plunger Pushed In VOM Meter Leads 12 volt Test Leads Test 4 Solenoid Hold In Coil Contact Continuity Test Use an ohmmeter set to the audible or Rx2K scale and connect the two ohmmeter leads to the two large post terminals Perform the preceding test 3 and check for continuity See Figure 8 77 The meter should indicate continuity if no continuity is indicated the solenoid should be replaced Repeat test several times to confirm condition Figure 8 77 Testing Hold In Coil Solenoid Contact Continuity 9 1 Section 9 Disassembly 9 Section 9 Disassembly WARNING Accidental Starts Disabling engine Accidental starting can cause severe injury or death Before working on the engine or equipment disable the engine as follows 1 Disconnect the spark plug lead s 2 Disconnect negative battery cable from battery General Clean all parts thoroughly as the engine is disassembled Only clean parts can be accurately inspected and gauged for wear or damage There are many commercially available cleaners that will quickly remove grease oil and grime from engine parts When such a cleaner is used follow the manufacturer s instructions and safety precautions carefully Make sure all traces of the cleaner are removed before the engine is reassembled and plac

American Standard 6065161.002 Indoor Furnishings User Manual

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