Kohler Command CV17-750 Service Manual
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Kohler Command CV17-750 Service Manual

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S
M
ERVICE
ANUAL
COMMAND
CV17-750
V
C
ERTICAL
RANKSHAFT

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Summary of Contents for Kohler Command CV17-750

  • Page 1 ERVICE ANUAL COMMAND CV17-750 ERTICAL RANKSHAFT...
  • Page 2 Contents Section 1. Safety and General Information ................Section 2. Tools & 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.
  • Page 3 Section 1 Safety and General Information 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.

  • Page 4: Section 1 Safety And General Information

    Section 1 Safety and General Information WARNING WARNING WARNING Explosive Gas can cause fires and Carbon Monoxide can cause severe Explosive Fuel can cause fires severe acid burns. nausea, fainting or death. and severe burns. Charge battery only in a well Avoid inhaling exhaust fumes, and ventilated area.
  • Page 5 Section 1 Safety and General Information 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. Identification Decal The engine identification numbers appear on a decal, or decals, affixed to the engine shrouding.
  • Page 6 A logo or symbol on oil containers identifies the API service class and SAE viscosity grade. See Figure 1-3. 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...
  • Page 7 ¹Perform these maintenance procedures more frequently under extremely dusty, dirty conditions. ²Only required for Denso starters. Not necessary on Delco starters. Have a Kohler Engine Service Dealer perform this service. ³Cleanout Kits 25 755 20-S (black) or 25 755 21-S (gold) allow cooling areas to be cleaned without removing shrouds.
  • Page 8 Section 1 Safety and General Information Dimensions in millimeters. Inch equivalents shown in [ ]. Figure 1-4. Typical Engine Dimensions CV Series with Standard Flat Air Cleaner.
  • Page 9 Section 1 Safety and General Information Dimensions in millimeters. Inch equivalents shown in [ ]. Figure 1-5. Typical Engine Dimensions CV Series with Commercial Mower Air Cleaner.
  • Page 10 Section 1 Safety and General Information Dimensions in millimeters. Inch equivalents shown in [ ]. Figure 1-6. Typical Engine Dimensions CV EFI Series with Heavy-Duty Air Cleaner.
  • Page 11 Section 1 Safety and General Information General Specifications 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 ............................
  • Page 12 Section 1 Safety and General Information General Specifications 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 ....................
  • Page 13 Section 1 Safety and General Information Crankcase Governor Cross Shaft Bore I.D. 6 mm Shaft New ......................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 ................
  • Page 14 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 ............. 82.988/83.013 mm (3.2672/3.2682 in.) Max.
  • Page 15 Section 1 Safety and General Information 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 ..............
  • Page 16 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 ..................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) ...............
  • Page 17 Section 1 Safety and General Information Stator Mounting Screw Torque ................6.2 N·m (55 in. lb.) Valve Cover Valve Cover Fastener Torque Gasket 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/Flange Screws and Spacers ............
  • Page 18 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 10.9 12.9 Size 1.2 (11) 1.7 (15) 2.9 (26) 4.1 (36) 5.0 (44) 2.0 (18)
  • Page 19 Section 1 Safety and General Information English Fastener Torque Recommendations for Standard Applications Tightening Torque: N·m (in. lb.) + or - 20% Bolts, Screws, Nuts and Fasteners Grade 2 or 5 Assembled Into Cast Iron or Steel Fasteners Into Aluminum Grade 2 Grade 5 Grade 8...
  • Page 20 By using tools designed for the job, you can properly service engines easier, faster, and safer! In addition, you’ll increase your service capabilities and customer satisfaction by decreasing engine downtime. Here is the list of tools and their source. Separate Tool Suppliers: Kohler Tools SE Tools Design Technology Inc. Contact your source 768 Burr Oak Drive 415 Howard St.
  • Page 21 Section 2 Tools & Aids ) . t . l a t f i l l a c i l f i l . s r i t i & . s t l i o i f i i f i i f i .
  • Page 22 Section 2 Tools & Aids - l e ) t f i l i ® e t i . r e l i o s i s , s t s i l ® e t i s i r c i t e t i ®...
  • Page 23 4. Use a flat washer with the correct I.D. to slip on tooth segment of the ring gear as shown. the capscrew and approximately 1” O.D. (Kohler Part No. 12 468 05-S). Assemble the capscrew 2. Grind off any burrs or sharp edges.
  • Page 24 Section 3 Troubleshooting Section 3 Troubleshooting Troubleshooting Guide 10. Diode in wiring harness failed in open circuit mode. When troubles occur, be sure to check the simple causes which, at first, may seem too obvious to be Engine Starts Hard considered.

  • Page 25: Section 3 Troubleshooting

    Section 3 Troubleshooting Engine Will Not Idle Engine Uses Excessive Amount of Oil 1. Dirt or water in the fuel system. 1. Incorrect oil viscosity/type. 2. Stale fuel and/or gum in carburetor. 2. Clogged or improperly assembled breather. 3. Faulty spark plugs. 3.
  • Page 26 Section 3 Troubleshooting • Check the condition of the oil. Drain the oil into a To test the crankcase vacuum with the manometer: container - the oil should flow freely. Check for metal chips and other foreign particles. 1. Insert the stopper/hose into the oil fill hole. Leave the other tube of manometer open to atmosphere.
  • Page 27 Section 3 Troubleshooting No Crankcase Vacuum/Pressure in Crankcase Possible Cause Solution 1. Disassemble breather, clean parts thoroughly, 1. Crankcase breather clogged or inoperative. reassemble, and recheck pressure. 2. Replace all worn or damaged seals and gaskets. 2. Seals and/or gaskets leaking. Loose or Make sure all fasteners are tightened securely.
  • Page 28 Section 3 Troubleshooting Leakdown Test Results Air escaping from crankcase 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”...
  • Page 29 Section 4 Air Cleaner and Air Intake System Section 4 Air Cleaner and Air Intake System Service Air Cleaners Check the air cleaner daily or before starting the engine. Check for and correct any buildup of dirt and General debris, along with loose or damaged components. These engines are equipped with a replaceable, high- density paper air cleaner element.

  • Page 30: Section 4 Air Cleaner And Air Intake System

    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 Precleaner genuine Kohler element. Handle new elements carefully; do not use if the sealing surfaces are bent or damaged. Element 5.
  • Page 31 Section 4 Air Cleaner and Air Intake System Air Cleaner Base Spitback Cup Precleaner Spitback Cup Gasket Rubber Seal Air Cleaner Cover Element Knob Seal Element Element Cover Cover Nut Knob Figure 4-5. Air Cleaner System Components - Standard. *Plenum air cleaner system does not use a precleaner. Element Cover Nut Wing Nut Element Cover...
  • Page 32 Section 4 Air Cleaner and Air Intake System Air Cleaner Components 4. Remove the base and gasket. Carefully feed the Whenever the air cleaner cover is removed, or the breather hose through the base. paper element or precleaner are serviced, check the following: 5.
  • Page 33 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 Figure 4-9. Heavy-Duty Air Cleaner. required. Handle the new elements carefully; do...
  • Page 34 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.
  • Page 35 Gasohol (up to 10% ethyl alcohol, 90% unleaded equipped with a fuel pump, the fuel tank outlet is gasoline by volume) is approved as a fuel for Kohler located above the carburetor inlet allowing gravity to engines. Other gasoline/alcohol blends are not feed fuel to the carburetor.

  • Page 36: Section 5 Fuel System And Governor

    N11236 rated fuel line; certified to meet CARB requirements. SPEC. NO. Standard fuel line may not be used. Order SERIAL NO. replacement hose by part number through a Kohler BUILD DATE Engine Service Dealer. OEM PROD. NO. EMISSION COMPLIANCE PERIOD:...
  • Page 37 Section 5 Fuel System and Governor Fuel System Tests When the engine starts hard, or turns over but will not start, it is possible that the problem is in the fuel system. To find out if the fuel system is causing the problem, perform the following tests. Troubleshooting –...
  • Page 38 Section 5 Fuel System and Governor Fuel Pump 3. Remove the pulse line that connects the pump to the crankcase. General 4. Install a new pump using the hex flange screws. These engines are equipped with a pulse type fuel pump.
  • Page 39 Section 5 Fuel System and Governor Slow Circuit: (See Figure 5-3) At 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.
  • Page 40 Section 5 Fuel System and Governor 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.
  • Page 41 Section 5 Fuel System and Governor Troubleshooting – Carburetor Related Causes Condition Possible Cause/Probable Remedy 1. Engine starts hard, runs roughly 1. Low idle fuel mixture/speed improperly adjusted. Adjust the low or stalls at idle speed. idle speed screw, then adjust the low idle fuel needle. 2.
  • Page 42 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.
  • Page 43 Section 5 Fuel System and Governor 5. Low Idle Fuel Needle Setting: Place the throttle NOTE: The tip of the idle fuel adjusting needle is tapered to critical dimensions. into the “idle” or “slow” position. Turn the low Damage to the needle and the seat in the idle fuel adjusting needle in (slowly) until engine carburetor body will result if the needle speed decreases and then back out approximately...
  • Page 44 Section 5 Fuel System and Governor 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 Governed body. Idle Spring 16.5 mm (0.65 in.)
  • Page 45 Use the carburetor repair kit (and the float repair kit if solenoid-equipped carburetors. float components are to be replaced). Refer to Figure 5-10 for parts identification. The Kohler part number 4. Remove the screws holding the throttle plate to and the Nikki lot number are stamped on the choke the throttle shaft, pull the throttle shaft from the side flange on top of the carburetor body.
  • Page 46 Section 5 Fuel System and Governor 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.
  • Page 47 Section 5 Fuel System and Governor 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...
  • Page 48 Section 5 Fuel System and Governor 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.
  • Page 49 Section 5 Fuel System and Governor 2. Remove the float pin screw and lift out the old NOTE: The carburetor is now disassembled for float, pin, and inlet needle. See Figure 5-18. appropriate cleaning and installation of Discard all of the parts. The seat for the inlet the parts in the overhaul kit.
  • Page 50 Section 5 Fuel System and Governor 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 5-21. Installing Slow Jet. Figure 5-24.
  • Page 51 Section 5 Fuel System and Governor 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 5-28. Installing Idle Fuel Adjusting Screw and Spring.
  • Page 52 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 5-32. Check Valve and Retaining Ring Installed. 6. Notice the small alignment tab and the small Figure 5-30.
  • Page 53 Section 5 Fuel System and Governor 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.
  • Page 54 Section 5 Fuel System and Governor 9. Install the new return spring onto the new choke Carburetor shaft, so the upper leg of the spring is between the two formed “stops” on the end of the choke Keihin BK Two-Barrel Carburetor (CV750) shaft.
  • Page 55 Section 5 Fuel System and Governor Adjustment *NOTE: The actual low idle speed depends on the application. Refer to the equipment NOTE: Carburetor adjustments should be made only manufacturer’s recommendations. The low after the engine has warmed up. idle speed for basic engines is 1200 RPM. To ensure best results when setting the low idle The carburetor is designed to deliver the correct fuel- fuel needle, the low idle speed should be...
  • Page 56 Section 5 Fuel System and Governor Lean Lean Adjust to Adjust to Midpoint Governed Midpoint Idle Spring Rich Rich Left Side Right Side 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.
  • Page 57 Section 5 Fuel System and Governor Fuel Bowl Bowl Drain Screw Figure 5-43. Fuel Bowl Removed From Carburetor. Figure 5-45. Float and Inlet Needle Details. 3. Remove the float pin screw and lift out the old 6. Install the float and inlet needle down into the float, pin and inlet needle.
  • Page 58 Section 5 Fuel System and Governor Fuel Bowl Bowl Drain Screw Figure 5-49. Fuel Bowl Removed From Carburetor. Figure 5-47. Checking Float Height. NOTE: Further disassembly of the fuel bowl is NOTE: Be sure to measure from the casting not necessary unless the Fuel Solenoid surface, not the rubber gasket, if still Kit, or Fuel Bowl Kit (obtained attached.
  • Page 59 Section 5 Fuel System and Governor Slow (Idle Fuel) Jets Main Nozzles O-Ring Main Jets Figure 5-51. Main Jets and Nozzles Removed. Figure 5-53. Slow Jets and O-Ring Detail. 4. Remove the screw securing the flat washer and 5. Remove the idle speed (RPM) adjustment screw ground lead (if equipped), from the top of the and spring from the carburetor.
  • Page 60 Section 5 Fuel System and Governor Nozzle End with Two Shoulders (Out/Down) Main Jets Figure 5-56. Float and Inlet Needle Details. Figure 5-54. Installing Main Nozzles and Main Jets. 13. Install the float and inlet needle down into the 9. Make sure the O-Ring near the bottom of each seat and carburetor body.
  • Page 61 Section 5 Fuel System and Governor 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.
  • Page 62 Section 5 Fuel System and Governor ® 8. Turn the old bushing upside down and use it as a 11. Place a drop of Loctite on the threads of each driver to carefully press or tap the new bushing new screw. Position and install the new choke into the carburetor body until it bottoms.
  • Page 63 Section 5 Fuel System and Governor 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.
  • Page 64 Section 5 Fuel System and Governor Adjustments Governor General General The engine is equipped with a centrifugal flyweight The governed speed setting is determined by the position of the throttle control. It can be variable or mechanical governor. It is designed to hold the engine constant, depending on the engine application.
  • Page 65 Section 5 Fuel System and Governor Sensitivity Adjustment 1. With the engine running, move the throttle Governor sensitivity is adjusted by repositioning the control to fast. Use a tachometer to check the governor spring in the holes of the governor lever. If RPM speed.
  • Page 66 Section 5 Fuel System and Governor Choke Lever Choke Lever Detail Screw Washer Spring Washer Lock Spacer Bushing Fastener Choke Cable Choke Lever Linkage (See Detail at Left) Screw and Nut Control Bracket Control Lever Fastener Throttle Lock Nut Cable Clamp Blower Housing Washer...
  • Page 67 Section 5 Fuel System and Governor Screw Washer Spring Washer Spacer Lock Nut Bushing Choke Linkage Hex Nut Screw Choke Cable Throttle Control Lever Clamp and Screw Lock Nut Control Bracket Screw Washer Spring Throttle Bushing Cable Throttle Linkage Fuel Pump Clamp Linkage Spring Fuel...

  • Page 68: Table Of Contents

    Section 5B EFI Fuel System Section 5B Electronic 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) ........................

  • Page 69: Description

    Section 5B EFI Fuel System Description 2. For plastic-cased ECU’s below 24 584 28-S, the system can be primed by manually cycling the fuel pump. WARNING a. Turn the key switch to the “on/run” position. The fuel pump will run for about three seconds and stop.

  • Page 70: Efi Fuel System Components

    Gasohol (up to 10% ethyl alcohol, 90% unleaded tank through the fuel line and in-line fuel filter. A fuel gasoline by volume) is approved as a fuel for Kohler pressure regulator maintains a system operating EFI engines. Other gasoline/alcohol blends are not pressure of 39 psi and returns any excess fuel to the approved.

  • Page 71: Important Service Notes

    Section 5B EFI Fuel System During certain operating periods such as cold starts, • Never use a quick battery charger to start the warm up, acceleration, etc., an air/fuel ratio richer engine. than 14.7:1 is required and the system operates in an “open loop”...

  • Page 72: Engine Speed Sensor

    Section 5B EFI Fuel System Two different ECU styles have been used in CV EFI To prevent engine over-speed and possible failure, a production. Each has a plastic case, but they differ in “rev-limiting” feature is programmed into the ECU. If having a 24 pin or 32 pin connector block, and are the maximum RPM limit (4500) is exceeded, the ECU identified as MSE 1.0 or MSE 1.1 respectively.
  • Page 73 Section 5B EFI Fuel System General The engine speed sensor is essential to engine Dual Aligning Rails 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 Corresponds To Corresponds mounted 1.5 ±...
  • Page 74 Section 5B EFI Fuel System General 3. a. Use an ohmmeter and connect the ohmmeter The throttle position sensor (TPS) is used to indicate leads as follows to test: (See chart on page throttle plate angle to the ECU. Since the throttle (by 5B.26 or 5B.29.).
  • Page 75 Section 5B EFI Fuel System “24 Pin” (MSE 1.0) Plastic-Cased ECU: Pin 7. Locate the service connector plug in the wiring circuits #8 and #4. harness. Connect a jumper wire from the TPS initialization pin #24 (violet wire) to the battery “32 Pin”...

  • Page 76: Engine (Oil) Temperature Sensor

    Section 5B EFI Fuel System 11. Reconnect the battery cable and all external loads. 9. Shut off the engine. If the learn procedure was Remove the rubber band from the throttle lever. successfully completed, the external loads Readjust the idle speed to the equipment removed/disconnected in Step 2 may be manufacturer’s specified setting and recheck the reconnected.

  • Page 77: Oxygen Sensor

    Section 5B EFI Fuel System General Oxygen Sensor 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.
  • Page 78 Section 5B EFI Fuel System The oxygen sensor can function only after being declines, without cycling, the engine may be heated by exhaust temperatures to a minimum of running lean due to incorrect TPS initialization. 375°C (709°F). A cold oxygen sensor will require Shut off the engine, perform TPS initialization, approximately 1-2 minutes at moderate engine load to and then repeat the test.

  • Page 79: Electrical Relay

    Section 5B EFI Fuel System b. If the resistance is less than 1.0 MΩ Ω Ω Ω Ω , the 2. Loosen and remove the oxygen sensor from the sensor is bad, replace it. exhaust manifold/muffler assembly. 5. With the oxygen sensor disconnected and 3.

  • Page 80: Fuel Injectors

    Section 5B EFI Fuel System 2. Connect the black lead of VOA meter to a chassis Terminal #87 - Terminal #86 - Feed To ground location. Connect the red lead to the #86 Ignition Switch Ignition Coils, terminal in relay connector (see Figure 5B-12). Set Voltage Fuel Injectors, meter to test resistance (Rx1).
  • Page 81 Section 5B EFI Fuel System Figure 5B-15. Style 2 Fuel Injector. General The fuel injectors mount into the throttle body/intake Multi-Orifice manifold, and the fuel rail attaches to them at the top Director Plate With end. Replaceable O-Rings on both ends of the injector Calibrated Opening prevent external fuel leakage and also insulate it from heat and vibration.
  • Page 82 Section 5B EFI Fuel System a. If flashing occurs, use an ohmmeter (Rx1 Listen Here scale) and check the resistance of each injector across the two terminals. Proper resistance is 12-20 Ω Ω Ω Ω Ω . If injector resistance is correct, check whether the connector and injector terminals are making a good connection.
  • Page 83 Section 5B EFI Fuel System 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”...

  • Page 84: Ignition System

    Section 5B EFI Fuel System Ignition System 2. Disconnect connector from relay and locate terminal #87 in connector. General 3. Using an ohmmeter set on the Rx1 scale, check A high-voltage, solid-state, battery ignition system is the resistance in circuits as follows: used with the EFI system.

  • Page 85: Spark Plugs

    ® RC12YC performance. Corrosion, moisture, and poor (Kohler Part No. 12 132 02-S) resistor spark plugs. connections are more likely the cause of operating Equivalent alternate brand plugs can also be used, but problems and system errors than an actual must be resistor plugs or permanent damage to the component.

  • Page 86: Fuel Pressure Regulator

    Section 5B EFI Fuel System pump preventing the continued delivery of fuel. In b. If the voltage was below 7, test the wiring this situation, the MIL will go on, but it will go back harness and relay as covered in the off after 4 cranking revolutions if system function is ‘‘Electrical Relay’’...
  • Page 87 Section 5B EFI Fuel System a. Remove the two screws securing the General mounting bracket to the regulator housing. The fuel pressure regulator assembly maintains the Remove the O-Ring and pull the regulator out required operating system pressure of 39 psi ± 3. A of the housing.

  • Page 88: Fuel Filter

    Section 5B EFI Fuel System 6. Install the new regulator by carefully pushing Fuel Rail and rotating it slightly into the base or housing. a. External Regulators with Square Base Housing Only; Install a new O-Ring between Fuel Rail the regulator and the mounting bracket. Set the mounting bracket into position.

  • Page 89: Throttle Body/Intake Manifold Assembly

    Special Oetiker if worn or damaged. The appropriate “TPS clamps (Kohler Part No. 24 237 05-S) are used on all Initialization Procedure” must be performed after any fuel line connections to prevent tampering and safety throttle shaft service.

  • Page 90: Initial Governor Adjustment

    Section 5B EFI Fuel System Idle Speed Screw Linkage Throttle Bushing Linkage Damper Spring Figure 5B-34. Throttle Linkage/Governor Lever Connection. 2. Check if the engine has a high-speed throttle stop Figure 5B-33. Idle Speed Screw Details. screw installed in the manifold casting boss. See Figure 5B-35.
  • Page 91 Section 5B EFI Fuel System B. Setting the Initial Adjustment 1. Check the split where the clamping screw goes through the governor lever. See Figure 5B-38. There should be a gap of at least 1/32". If the tips are touching and there is no gap present, the lever should be replaced.

  • Page 92: Troubleshooting

    Section 5B EFI Fuel System 4. Verify that the governor has been set correctly. Engine starts hard or fails to start when hot With the linkage still retained in the “Full 1. Faulty spark plugs Throttle” position (Step 2), unsnap the bushing 2.

  • Page 93: Electrical System

    Section 5B EFI Fuel System Electrical System Cleaning the connectors and grounds will solve problems in many cases. In an emergency situation, The EFI system is a 12 VDC negative ground system, simply disconnecting and reconnecting the connectors designed to operate down to a minimum of 7.0 volts. may clean up the contacts enough to restore operation, If system voltage drops below this level, the operation at least temporarily.
  • Page 96 Section 5B EFI Fuel System “32 Pin” (MSE 1.1) Plastic-Cased ECU Systems Pin # Function Permanent Battery Voltage Switched Battery Voltage TPS Set; “Auto-Learn” Initialization Terminal Throttle Position Sensor (TPS) and Temperature Sensor Ground Not Used Oil Temperature Sensor Input Not Used Throttle Position Sensor (TPS) Input Speed Sensor Input (+)

  • Page 97: Fuel System

    Section 5B EFI Fuel System Fuel System Fault Codes The ECU continuously monitors engine operation WARNING: Fuel System Under Pressure! against preset performance limits. If the operation is The fuel system operates under high pressure. System outside the limits, the ECU activates the MIL and pressure must be relieved through the test valve in the fuel stores a diagnostic code in its fault memory.
  • Page 98 Section 5B EFI Fuel System Example of Diagnostic Display 1. Diagnostic display initiated through ignition key sequencing. Long Pause Short Pause Code 32 Long Pause Code 61 Long Pause Light remains on at end of transmission Figure 5B-40. After the problem has been corrected, the fault codes may be cleared as follows. 1.
  • Page 99 Section 5B EFI Fuel System Diagnostic Code Summary cont. 2 " " n 3 " " n c i l 3 " " n u l i i r c c i t c i t : t i : t i v i t y t i i n i...
  • Page 100 Section 5B EFI Fuel System Code: Code: Source: Engine Speed Sensor Source: Throttle Position Sensor (TPS) Explanation: ECU receiving inconsistent tooth Explanation: Unrecognizable signal is being sent count signals from speed sensor. from sensor (too high, too low, Expected Engine inconsistent).
  • Page 101 Section 5B EFI Fuel System Code: If the engine is still running rich Source: (laboring, short on power) or lean popping or misfiring), the fuel Explanation: ECU is unable to recognize or process signals from its memory. mixture is suspect, probably incorrect Expected Engine TPS initialization or low fuel pressure.
  • Page 102 Section 5B EFI Fuel System Code: Code: Source: Oxygen Sensor/Fuel System Source: Oxygen Sensor/Fuel System Explanation: “System too Rich” Temporary fuel Components adaptation control is at the upper Explanation: Long term fuel adaptation control is limit. at the upper or lower limit. Expected Engine Expected Engine Response:...
  • Page 103 Section 5B EFI Fuel System Code: 2. Engine Wiring Harness Related Source: Engine (Oil) Temperature Sensor a. Broken or shorted wire in harness. Explanation: Not sending proper signal to ECU. ECU pin 18 to TPS pin 1. Expected Engine ECU pin 4 to TPS pin 2. Response: Engine will be hard to start because ECU pin 8 to TPS pin 3.
  • Page 104 Section 5B EFI Fuel System 3. Fuel Pump Relay Related Expected Engine Response: a. Bad fuel pump relay. Engine will run normally if no other Primary side functional but pin 30 to pin 87 errors are present. remains open. Primary side pin 85 to pin 86 is either open, or shorted during engine Possible Causes: operation.

  • Page 105: Troubleshooting Flow Chart

    Section 5B EFI Fuel System Code: Troubleshooting Flow Chart Source: The following flow chart provides an alternative Explanation: Denotes the end of fault codes. If method of troubleshooting the EFI system. The chart signaled first, no other fault codes will enable you to review the entire system in about are present.
  • Page 106 Section 5B EFI Fuel System *Operate for an appropriate period of time based upon original fault codes. Figure 5B-41. 5B.39...

  • Page 107: Flow Chart Diagnostic Aids

    Section 5B EFI Fuel System Flow Chart Diagnostic Aids 14. Code 56 - Pump Relay, “32 Pin” (MSE 1.1) Plastic-Cased ECU only. Diagnostic Aid #1 “SYSTEM POWER” (MIL does not 15. Code 61 - End of Fault/Blink Code Transmission illuminate when key is turned “on”) Diagnostic Aid #3 “RUN/ON”...
  • Page 108 Section 5B EFI Fuel System Diagnostic Aid #5 “FUEL PUMP” (fuel pump not Diagnostic Aid #8 “FUEL SYSTEM-ELECTRICAL” (no fuel delivery) turning on) Possible causes: Possible causes: 1. Fuel pump fuse 1. No fuel 2. Fuel pump circuit problem 2. Air in fuel rail 3.
  • Page 109 Section 6 Lubrication System Section 6 Lubrication System General NOTE: Using other than service class SG, SH, SJ or higher oil, or extending oil change intervals This engine uses a full pressure lubrication system, longer than recommended can cause engine delivering oil under pressure to the crankshaft, damage.

  • Page 110: Section 6 Lubrication System

    Section 6 Lubrication System Checking Oil Level NOTE: To prevent extensive engine wear or damage, always maintain the proper oil level in the The importance of checking and maintaining the crankcase. Never operate the engine with the proper oil level in the crankcase cannot be oil level below the low mark or above the full overemphasized.
  • Page 111 In order to be effective, the oil cooler must be kept free (every 200 hours of operation). Always use a genuine of debris. 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;...
  • Page 112 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.
  • Page 113 Section 7 Retractable Starter 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. 2.

  • Page 114: Section 7 Retractable Starter

    Section 7 Retractable Starter 6. Tie a single knot in one end of the new rope. Pawls (Dogs) Replacement To replace the pawls, follow disassembly steps 1-4 7. Rotate the pulley counterclockwise (when and reassembly steps 3-8 on the following pages. A viewed from pawl side of pulley) until the spring pawl repair kit is available which includes the is tight (approximately 6 full turns of pulley).
  • Page 115 Return the pulley to the housing and repeat step 2. Replace all worn or damaged components. Use 5 before separating the pulley and housing. only genuine Kohler replacement parts as specified in the Parts Manual. All components shown in Figure 7-1 are available as service...
  • Page 116 Section 7 Retractable Starter 3. Do not attempt to rewind a spring that has come out of the keeper. Order and install a new spring Pawl and keeper assembly. 4. Clean all old grease and dirt from the starter components. Generously lubricate the spring and center shaft with any commercially available bearing grease.
  • Page 117 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- ®...

  • Page 118: Section 8 Electrical System And Components

    Section 8 Electrical System and Components Normal: A plug taken from an engine operating under Wet Fouled: A wet plug is caused by excess fuel or oil normal conditions will have light tan or gray colored in the combustion chamber. Excess fuel could be deposits.
  • Page 119 Section 8 Electrical System and Components Battery 2. Keep the cables, terminals, and external surfaces of the battery clean. A build-up of corrosive acid or grime on the external surfaces can cause the General battery to self-discharge. Self-discharge occurs A 12-volt battery with 400 cold cranking amps is rapidly when moisture is present.
  • Page 120 Section 8 Electrical System and Components Electronic CD Ignition Systems Carburetor Solenoid Starter and Ignition Spark Pressure Carburetor Module Advance Safety Green Solenoid Input Module Input White (Optional) Oil Pressure B+ and Spark Ignition Safety Input Carburetor Plugs Modules Solenoid Input Violet Rectifier-...
  • Page 121 Section 8 Electrical System and Components Kill Switch or Ignition ‘‘Off’’ Position of Modules Key Switch Spark Plug Magnet 0.28/0.33 mm (0.011/0.013 in.) Flywheel Air Gap Figure 8-4. Capacitive Discharge (Fixed Timing) Ignition System. The timing of the spark is controlled by the location of the flywheel magnet group as referenced to engine top dead center.
  • Page 122 Section 8 Electrical System and Components B. Capacitive Discharge with Electronic Spark Advance (SMART-SPARK ™ SMART-SPARK equipped engines utilize an ™ electronic capacitive discharge ignition system with electronic spark advance. A typical application (Figure 8-6) consists of the following components: •...
  • Page 123 2. Test for spark on both cylinders with Kohler CAUTION: High-Energy Electric Spark! ignition tester (see Section 2). Disconnect one The CD ignition systems produce a high-energy electric...
  • Page 124 Section 8 Electrical System and Components a. If one side is not firing, check all wiring, a. If the problem is gone, the electrical system on connections, and terminations on that side. If the unit is suspect. Check the key switch, wiring is okay, replace ignition module and wires, connections, safety interlocks, etc.
  • Page 125 All modules with vendor part numbers MA-2, MA-2A, or MA-2B (Kohler Part No. 24 584 03) should be replaced with 24 584 11 or 24 584 15-S. For small modules with vendor numbers MA-2C or MA-2D (Kohler Part No.
  • Page 126 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 24 584 03 or legs of the module. The ignition module 24 584 15-S or 24 584 11 air gap is critical to proper system 24 584 36-S...
  • Page 127 Section 8 Electrical System and Components a. If correct voltage is not measured, connect To Test – Using 25 761 21-S Tester black voltmeter lead directly to the negative (-) post of the battery and test voltage again ASAM (only) Test Procedure in both key positions.
  • Page 128 Section 8 Electrical System and Components Figure 8-12. Figure 8-13. ** The tester is powered by a 9-volt battery. Most 2. Check the SAM part number stamped on the side SAMs are designed to operate down to a minimum of the housing. Verify that you have an analog of 7.25 volts.
  • Page 129 Section 8 Electrical System and Components b. If it is a DSAM (all except 24 584 09 or To Test – Using 25 761 40-S Tester 24 584 10), connect the tester as follows: DSAM/ASAM Test Procedure • Yellow tester lead to the long yellow module lead.
  • Page 130 Section 8 Electrical System and Components 4. If you get a “-“ sign instead of the numerical ** The tester is powered by a 9-volt battery. Most sequence, and/or an “F” at the end of the test SAMs are designed to operate down to a minimum cycle, recheck all of the connections, check the of 7.25 volts.
  • Page 131 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. 8.15...
  • Page 132 Section 8 Electrical System and Components Figure 8-18. Wiring Diagram - 15/20/25 Amp Regulated Battery Charging System with Variable Ignition Timing SMART-SPARK ™ Figure 8-19. 15 Amp Stator and Rectifier-Regulator. Figure 8-20. 20 Amp Stator and Rectifier-Regulator. 8.16...
  • Page 133 Section 8 Electrical System and Components 1st Style 25 Amp Stator 2nd Style Figure 8-21. 25 Amp Stator and Rectifier-Regulators. 3 Amp Unregulated Charging System Ground-To-Kill Lead (White) Light Ignition (Blue) Modules Spark Spark (Red) Plug Plug Keyswitch (Black) Optional Diode 3 Amp/70 Watt Fuse...
  • Page 134 Section 8 Electrical System and Components 3 Amp Charging Stator Lighting Lead (Yellow) Diode Charging Lead (Black) Lighting Stator Figure 8-23. 3 Amp/70 Watt Stator. To Test – Stator NOTE: Disconnect all electrical connections attached The stator is mounted on the crankcase behind the to the rectifier-regulator.
  • Page 135 Section 8 Electrical System and Components 20/25 Amp Rectifier-Regulators 3. Plug the tester into the proper AC outlet/power supply for tester being used. Turn on the power 1. Connect the single lead adapter in between the B+ switch. See Figure 8-26. The ‘‘POWER’’ light (center) terminal of the rectifier-regulator being should be illuminated and one of the four status tested and the squared single end of the tandem...
  • Page 136 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.
  • Page 137 Section 8 Electrical System and Components 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.
  • Page 138 Section 8 Electrical System and Components Troubleshooting Guide 15/20/25 Amp Battery Charging Systems When problems occur in keeping the battery charged or the battery charges at too high a rate, the problem can usually be found somewhere in the charging system or with the battery. NOTE: Always zero ohmmeter on each scale before testing to ensure accurate readings.
  • Page 139 Section 8 Electrical System and Components Troubleshooting Guide 3 Amp Battery Charging System with 70 Watt Lighting Stator NOTE: Zero ohmmeters on each scale to ensure accurate readings. Voltage tests should be made with engine running at 3000 RPM - no load. Battery must be good and fully charged. Conclusion Problem Test...
  • Page 140 Section 8 Electrical System and Components NOTE: If the starter does not crank the engine, shut Electric Starting Motors off the starter immediately. Do not make Some engines in this series use inertia drive starting further attempts to start the engine until the motors while most use solenoid shift starters.
  • Page 141 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.
  • Page 142 7. The splines should have a light film of lubricant. ring in the inner groove (see Figure 8-36). Slide Relubricate as necessary with Kohler starter drive the collar over the inner halves to hold them in lubricant (see Section 2). Reinstall or replace the position.
  • Page 143 Section 8 Electrical System and Components Retaining Ring Installation Starter Disassembly 1. Position the retaining ring in the groove in one of 1. Remove the drive components following the the inner halves. Assemble the other half over the instructions for servicing the drive. top and slide on the outer collar.
  • Page 144 Section 8 Electrical System and Components NOTE: Use a brush holder tool to keep the 2. Insert the armature into the starter frame. Make brushes in the pockets. A brush holder sure the magnets are closer to the drive shaft end tool can easily be made from thin sheet of the armature.
  • Page 145 7. Lubricate the drive shaft with Kohler starter drive with the ring gear into the retracted position. lubricant (see Section 2). Install the drive components following the instructions for servicing the starter drive.
  • Page 146 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.
  • Page 147 Section 8 Electrical System and Components Phillips Head Screws Torx Head Screws Figure 8-45. Removing Solenoid Screws. Figure 8-46. Solenoid Removed from Starter. 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.
  • Page 148 Section 8 Electrical System and Components 7. Remove the drive lever pivot bushing and backing plate from the end cap. See Figure 8-51. Figure 8-48. Removing Thru Bolts. 5. Remove the commutator end plate assembly, Figure 8-51. containing the brush holder, brushes, springs, and locking caps.
  • Page 149 Section 8 Electrical System and Components Figure 8-53. Retaining Ring Detail. Figure 8-54. Removing Retaining Ring. 11. Remove the retainer from the armature shaft. 12. Remove the drive pinion assembly from the Save the stop collar. armature. NOTE: Do not reuse the old retainer. 13.
  • Page 150 Section 8 Electrical System and Components Inspection Commutator O.D. 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.
  • Page 151 The brushes and springs are serviced as a set (4). Use Clean the drive lever and armature shaft. Apply Brush and Spring Kit, Kohler Part No. 25 221 01-S, if Kohler electric starter drive lubricant (see Section 2) replacement is necessary.
  • Page 152 Section 8 Electrical System and Components 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 8-62.
  • Page 153 Section 8 Electrical System and Components Figure 8-66. Installing Thrust Washer. Figure 8-68. Removing Retaining Clips. 10. Starter reassembly when replacing the Brushes/ b. Position each of the brushes back in their slots Brush Holder Assembly: so they are flush with the I.D. of the brush holder assembly.
  • Page 154 Section 8 Electrical System and Components Figure 8-70. Installing Brush Holder Assembly Figure 8-72. Torquing Brush Holder Screws. using Tool with Extension. 13. Hook the plunger behind the upper end of the 11. Install the end cap onto the armature and frame, drive lever, and install the spring into the aligning the thin raised rib in the end cap with solenoid.
  • Page 155 Section 8 Electrical System and Components Solenoid Test Procedure 12 volt Test Leads Momentary Solenoid Shift Style Starters Connection Only Disconnect all leads from the solenoid including the positive brush lead attached to the lower stud VOM Leads terminal. Remove the mounting hardware and separate the solenoid from the starter for testing.
  • Page 156 Section 8 Electrical System and Components 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 VOM Meter continuity.
  • Page 157 Section 9 Disassembly Section 9 Disassembly 16. Remove valve covers. WARNING: Accidental Starts! 17. Remove ignition modules. Disabling engine. Accidental starting can cause severe 18. Remove intake manifold. injury or death. Before working on the engine or 19. Remove spark plugs. equipment, disable the engine as follows: 1) Disconnect the 20.

  • Page 158: Section 9 Disassembly

    Section 9 Disassembly 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.
  • Page 159 Section 9 Disassembly Figure 9-6. Removing Standard Element and Figure 9-8. Removing Commercial Mower Element and Precleaner. Precleaner. 3. Remove the element cover, element and precleaner. See Figure 9-6. Hex Flange Nuts (2) Lower Mounting Screws (Some Models) Figure 9-7. Removing Standard Air Cleaner Base. 4.
  • Page 160 Section 9 Disassembly 4. Remove the two upper screws securing the air Heavy Duty Air Cleaner cleaner mounting bracket to the blower housing 1. Disconnect the breather hose from the fitting in adapter or elbow. Remove the hex flange nuts and remove the air cleaner assembly.
  • Page 161 Section 9 Disassembly Pulse Hose Figure 9-14. Removing Throttle Control Bracket. Figure 9-16. Disconnecting Pulse Line from Crankcase. Fuel Pump Inlet Hose Outlet Hose (To Carburetor) Pulse Hose Mounting Screws Figure 9-15. Removing Control Panel. Figure 9-17. Pulse Fuel Pump Details. Remove Fuel Pump 2.
  • Page 162 Section 9 Disassembly Governor Lever Control Bracket Figure 9-18. Removing Control Bracket. Figure 9-20. Removing Governor Lever. Remove Carburetor Air Cleaner Brackets (Some Models) WARNING: Explosive Fuel! Gasoline may be present in the carburetor and fuel system. Gasoline is extremely flammable, and its vapors can explode if ignited.
  • Page 163 Section 9 Disassembly 5. If necessary, the carburetor, throttle linkage and 3. Remove the carburetor, throttle linkage and governor lever can be separated. Reattach the governor lever as an assembly. bushings to the linkage following separation to avoid losing them. Remove Electric Starter Motor 1.
  • Page 164 Section 9 Disassembly 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.
  • Page 165 Section 9 Disassembly 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 9-30. Removing Flywheel Screen. 6. Remove the remaining hex flange screws securing the blower housing.
  • Page 166 Section 9 Disassembly Figure 9-37. Removing Valve Cover. Figure 9-35. Break Breather Cover Seal. Remove Ignition Modules 5. Remove the breather cover and gasket (if used). 1. Disconnect the lead(s) from each ignition module. See Figure 9-36. See Figure 9-38. SMART-SPARK ™...
  • Page 167 Section 9 Disassembly Aluminum Intake Manifold 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.
  • Page 168 Section 9 Disassembly 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.
  • Page 169 Section 9 Disassembly Valve Keepers Retainer Spring Figure 9-45. Removing Rocker Arm. Figure 9-47. Valve Components. 2. Compress the valve springs using a valve spring compressor. See Figure 9-46. Valve Seal Figure 9-48. Intake Valve Seal Location. NOTE: These engines use valve stem seals on the Figure 9-46.
  • Page 170 Section 9 Disassembly Figure 9-49. Removing Plastic Grass Screen. Figure 9-51. Removing Flywheel Fastener Using Strap Wrench. 2. Remove the four hex flange screws or hex studs and washers. Remove the plastic fan from the 2. Remove the hex flange screw and washer. flywheel.
  • Page 171 Section 9 Disassembly 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.
  • Page 172 Section 9 Disassembly 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 9-57. Removing Governor Cross Shaft Hitch Pin (6 mm Shaft Design). Figure 9-60.
  • Page 173 Section 9 Disassembly 3. Repeat the above procedure for the other Remove Flywheel End Oil Seal connecting rod and piston assembly. 1. Remove the oil seal from the crankcase. See Figure 9-63. Remove Crankshaft 1. Carefully pull the crankshaft from the crankcase. See Figure 9-62.
  • Page 174 Section 10 Inspection and Reconditioning Section 10 Inspection and Reconditioning This section covers the operation, inspection, and Operation repair/reconditioning of major internal engine The ACR mechanism consists of a flyweight, spring components. The following components are not and pivoting control pin assembly attached to the gear covered in this section.

  • Page 175: Section 10 Inspection And Reconditioning

    Section 10 Inspection and Reconditioning Inspect the crankshaft bearing surfaces for scoring, The connecting rod journal can be ground one size grooving, etc. Measure the running clearance between under. When grinding the crankshaft, grinding stone the crankshaft journals and their respective bearing deposits can get caught in the oil passages, which bores.
  • Page 176 Check the size frequently. cylinder wall. It washes the necessary lubricating oils off the piston and cylinder wall. As raw fuel seeps NOTE: Kohler pistons are custom-machined to down the cylinder wall, the piston rings make metal exacting tolerances. When oversizing a to metal contact with the wall.
  • Page 177 Inspect the ring gear for cracks or damage. Kohler NOTE: Do not use a feeler gauge to measure piston- does not provide ring gears as a serviceable part.
  • Page 178 Section 10 Inspection and Reconditioning 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.
  • Page 179 Section 10 Inspection and Reconditioning Normal: Even after long hours of operation a valve Leakage: A poor grind on face or seat of valve will can be reconditioned and reused if the face and allow leakage resulting in a burned valve on one side margin are in good shape.
  • Page 180 Section 10 Inspection and Reconditioning Excessive Combustion Temperatures: The white Stem Corrosion: Moisture in fuel or from deposits seen here indicate very high combustion condensation are the most common causes of valve temperatures, usually due to a lean fuel mixture. stem corrosion.
  • Page 181 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 Valve Seat excessive oil consumption.
  • Page 182 Section 10 Inspection and Reconditioning Ring failure is usually indicated by excessive oil Detonation damage occurs when a portion of the fuel consumption and blue exhaust smoke. When rings charge ignites spontaneously from heat and pressure fail, oil is allowed to enter the combustion chamber shortly after ignition.
  • Page 183 Section 10 Inspection and Reconditioning 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.
  • Page 184 Check the base surface of the hydraulic lifters for wear Piston 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. Compression “Bleeding”...
  • Page 185 Section 10 Inspection and Reconditioning Disassembly Reassembly The governor gear must be replaced once it is 1. Install the locking tab thrust washer on the removed from the oil pan. governor gear shaft with the tab down. NOTE: The governor gear is held onto the shaft by 2.
  • Page 186 Section 10 Inspection and Reconditioning Piston Spring Roll Pin Figure 10-16. Oil Pump, Oil Pickup, and Relief Figure 10-18. Oil Pressure Relief Valve Piston and Valve (Original Style). 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.
  • Page 187 Section 10 Inspection and Reconditioning 5. After torquing, rotate the gear and check for freedom of movement. Make sure there is no binding. If binding occurs, loosen the screws, reposition the pump, retorque the hex flange screws and recheck the movement. Crankcase Breather System The breather system is designed to control the amount of oil in the head area and still maintain the necessary...
  • Page 188 Section 11 Reassembly Section 11 Reassembly General 16. Install blower housing and outer baffles. 17. Install Oil Sentry NOTE: Make sure the engine is assembled using all 18. Install control panel. specified torque values, tightening sequences, 19. Install valve covers. and clearances.

  • Page 189: Section 11 Reassembly

    Section 11 Reassembly Figure 11-4. Installing Governor Cross Shaft Hitch Figure 11-2. Installing Oil Seal in Crankcase. Pin (6 mm Shaft). Install Governor Cross Shaft 1. Lubricate the governor cross shaft bearing surfaces in the crankcase with engine oil. 2. Slide the small lower washer onto the governor cross shaft and install the cross shaft from the inside of the crankcase.
  • Page 190 Section 11 Reassembly Install Crankshaft 1. Stagger the piston rings in the grooves until the end gaps are 120° apart. The oil ring rails should 1. Carefully slide the flywheel end of the crankshaft also be staggered. through the main bearing in the crankcase. See Figure 11-7.
  • Page 191 Section 11 Reassembly 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.) Figure 11-12. Apply Camshaft Lubricant to Cam 6 mm Straight Shank Lobes.
  • Page 192 Section 11 Reassembly Governor Gear Assembly Determining Camshaft End Play The governor gear assembly is located inside the oil 1. Install the shim removed during disassembly onto the camshaft. pan. If service was required, and the governor was removed, refer to the assembly procedures under ‘‘Governor Gear Assembly’’...
  • Page 193 Section 11 Reassembly Install Oil Pan Assembly 6. Install the ten hex flange screws securing the oil pan to the crankcase. Torque the fasteners in the RTV sealant is used as a gasket between the oil pan sequence shown in Figure 11-18 to 24.4 N·m and the crankcase on CV17-23 engines.
  • Page 194 Section 11 Reassembly Install Flywheel WARNING: Damaging Crankshaft and Flywheel Can Cause Personal Injury! Using improper procedures to install the flywheel can crack or damage the crankshaft and/or flywheel. This not only causes extensive engine damage, but can also cause personal injury, since broken fragments could be thrown from the engine.
  • Page 195 Section 11 Reassembly 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.
  • Page 196 Section 11 Reassembly Figure 11-28. Installing Supports for Metal Grass Figure 11-30. Applying Camshaft Lubricant to Screen. Bottom of Lifters. 2. Tighten the supports with a torque wrench to 3. Note the mark or tag identifying the hydraulic 9.9 N·m (99 in. lb.). See Figure 11-29. The grass lifters as either intake or exhaust and cylinder 1 screen will be installed to the supports after the or cylinder 2.
  • Page 197 Section 11 Reassembly Intake Valve Seal Figure 11-32. Match Numbers on Cylinder Barrel Figure 11-34. Intake Valve Seal Location. and Head. Assemble Cylinder Heads 4. If the breather reeds and stops were removed Prior to installation, lubricate all components with from the crankcase, reinstall them at this time engine oil, paying particular attention to the lip of the and secure with the hex flange screw.
  • Page 198 Section 11 Reassembly Figure 11-36. Installing Valves with Valve Spring Figure 11-37. Torquing Cylinder Head Fasteners. Compressor. 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 Install Cylinder Heads (370 in.
  • Page 199 Section 11 Reassembly 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.
  • Page 200 Section 11 Reassembly 3. Install new plugs and torque to 24.4-29.8 N·m (18-22 ft. lb.). See Figure 11-44. Figure 11-42. Torquing Rocker Arm Screws. 4. Use a spanner wrench or rocker arm lifting tool Figure 11-44. Installing Spark Plugs. (see Section 2), to lift the rocker arms and position the push rods underneath.
  • Page 201 Section 11 Reassembly 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.
  • Page 202 Section 11 Reassembly 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.
  • Page 203 Section 11 Reassembly Install Blower Housing and Outer Baffles NOTE: Do not completely tighten screws until all items are installed to allow shifting for hole alignment. 1. Pull the wire harness and spark plug leads out through the appropriate openings in the shrouding.
  • Page 204 Section 11 Reassembly Figure 11-61. Tightening Short Screws for Outer Figure 11-59. Installing Blower Housing. Baffles. 3. Position the outer baffles and secure using the 4. Tighten all of the shrouding fasteners. Torque the four hex flange screws (two long, two short) in blower housing screws to 6.2 N·m (55 in.
  • Page 205 Section 11 Reassembly Install Oil Sentry™ (If So Equipped) 1. Apply pipe sealant with Teflon ® (Loctite ® 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.
  • Page 206 Section 11 Reassembly Gasket/RTV style cover ..... 3.4 N·m (30 in. lb.) Install Valve Covers Black O-Ring style cover Three valve cover designs have been used. The earliest w/shoulder screws ......5.6 N·m (50 in. lb.) type used a gasket and RTV sealant between the cover w/screws and spacers ....
  • Page 207 Section 11 Reassembly Figure 11-67. Installing Carburetor, Throttle Figure 11-70. Install Governor Lever to Shaft. Linkage, and Governor Lever. 2. Make sure the throttle linkage is connected to the governor lever and the throttle lever on the carburetor. See Figure 11-71. Figure 11-68.
  • Page 208 Section 11 Reassembly Bushing Choke Linkage Lever Figure 11-74. Installing Lower Support Control Figure 11-72. Choke Linkage Details (Two-Barrel Bracket. Models). 7. Secure the control panel to the blower housing with the two screws (Models without a Heavy- Duty Air Cleaner). See Figure 11-75. Figure 11-73.
  • Page 209 Section 11 Reassembly 10. Connect the Oil Sentry™ Indicator light wires. 2. One-Barrel Carburetor Models: Install the Attach governor spring to governor lever. See standard throttle control bracket and the air Figure 11-76 and appropriate charts on pages cleaner support bracket (if used) to the cylinder 11.23 through 11.25.
  • Page 210 Section 11 Reassembly Item Description Bracket, speed control Clamp, cable (some applications) Kill Switch (some applications) Lever, choke (top position) Lever, throttle control (middle) Linkage, choke control Lever, throttle actuator (bottom) Screw, M5x0.8x20 Washer, wave Washer, flat (3) Spring, choke return Nut, M5x0.8 lock Figure 11-78.
  • Page 211 Section 11 Reassembly 8 mm Governor Lever and Hole Position/RPM Chart Governor Lever CV18 Engines Intended Standard Engine Mounted Throttle Control Maximum RPM Throttle Control Pivot Shaft High Idle Spring Color Hole No. Spring Color Hole No. 3888 Green 3600 Orange 3780 3500...
  • Page 212 Section 11 Reassembly 8 mm Governor Lever and Hole Position/RPM Charts cont. CV26, CV745 EFI Engines Intended With WAWB (Wide Area Walk Standard Throttle Control Governor Shaft Maximum RPM Behind) Throttle Control Configuration Spring Color High Idle Spring Color Hole No. Hole No.
  • Page 213 Section 11 Reassembly 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.
  • Page 214 Section 11 Reassembly Lower Screws Figure 11-86. Tightening Lower Base/Bracket Figure 11-84. Breather Hose and Separator Details. Screws (Some Models). 2. Position a new gasket and the air cleaner base on 4. Install the air cleaner components as described in the studs while carefully pulling the loose end of Section 4.
  • Page 215 Section 11 Reassembly 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. Install the hex flange nuts to the exhaust studs. Torque hex flange nuts to 24.4.
  • Page 216 Section 11 Reassembly Prepare the Engine for Operation The engine is now completely reassembled. Before starting or operating the engine, be sure to do the following. 1. Make sure all hardware is tightened securely. 2. Make sure the oil drain plugs, oil sentry pressure switch, and a new oil filter are installed.
  • Page 217 FORM NO.: TP-2450-C ISSUED: 3/94 REVISED: 3/06 LITHO IN U.S.A. FOR SALES AND SERVICE INFORMATION IN U.S. AND CANADA, CALL 1-800-544-2444 ENGINE DIVISION, KOHLER CO., KOHLER, WISCONSIN 53044...

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