Operation Engine Models: KG6208 Naturally Aspirated Propane, Liquefied Petroleum Gas (LPG) Natural Gas (NG) Fueled TP-7095 4/18a
California Proposition 65 WARNING Engine exhaust from this product contains chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm. California Proposition 65 WARNING This product contains and/or emits chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm. Product Identification Information Product identification numbers determine service parts.
Table of Contents Safety Precautions and Instructions ........................................................................................................................................ 5 Introduction .............................................................................................................................................................................. 11 Service Assistance..............................................................................................................
Section 5. 5.1 5.2 5.3 5.4 5.5 Section 6. 6.1 6.2 6.3 6.4 6.5 4 Storage.................................................................................................................................................... 45 Preparation............................................................................................................................................................. 45 Short-Term Storage (Less than 30 Days).............................................................................
Safety Precautions and Instructions Read and follow all safety precautions and instructions. SAVE THESE INSTRUCTIONS. This manual has several types of safety precautions and instructions: Danger, Warning, Caution, and Notice. DANGER Danger indicates the presence of a hazard that will cause severe personal injury, death, or substantial property damage. WARNING Warning indicates the presence of a hazard that can cause severe personal injury, death, or substantial property damage.
Battery WARNING Sulfuric acid in batteries. Can cause severe injury or death. Wear protective goggles and clothing. Battery acid may cause blindness and burn skin. Battery electrolyte is a diluted sulfuric acid. Battery acid can cause severe injury or death. Battery acid can cause blindness and burn skin. Always wear splashproof safety goggles, rubber gloves, and boots when servicing the battery. Do not open a sealed battery or mutilate the battery case.
Engine Fluids and Chemical Products WARNING Handling caustic engine fluids and chemical products can cause severe chemical burns, nausea, fainting, or death. Most chemicals such as used engine oil, antifreeze/coolant, rustproofing agent, inhibiting oil, degreasing agent, spray paint, and adhesives are hazardous to health. Read and follow the user information found on the packaging. Avoid inhalation and skin contact. Use only in well-ventilated areas and use a protective mask when spraying.
Fuel System WARNING Explosive fuel vapors. Can cause severe injury or death. Use extreme care when handling, storing, and using fuels. The fuel system. Explosive fuel vapors can cause severe injury or death. Vaporized fuels are highly explosive. Use extreme care when handling and storing fuels. Store fuels in a well-ventilated area away from spark-producing equipment and out of the reach of children.
Hazardous Voltage/Moving Parts WARNING Moving parts. Can cause severe injury or death. Operate the engine only when all guards and electrical enclosures are in place. Stay away from moving parts while the engine is in operation. Servicing the engine when it is operating. Exposed moving parts will cause severe injury or death. Keep hands, feet, hair, clothing, and test leads away from the belts and pulleys when the engine is running. Replace guards, screens, and covers before operating the engine.
TP-7095 4/18
Introduction This manual provides operating and maintenance instructions for Kohler engines. Keep this manual with the equipment for future reference. Refer to the service manual for detailed information on adjusting and servicing the engine. Read this manual and carefully follow all procedures and safety precautions to ensure proper equipment operation and to avoid bodily injury. Read and follow the Safety Precautions and Instructions section at the beginning of this manual.
Service Assistance For professional advice and conscientious service, please contact your nearest Kohler distributor or dealer. • Visit the Kohler Co. website at KOHLERPower.com. • Look at the labels and decals on your Kohler product or review the appropriate literature or documents included with the product. • Call toll free in the US and Canada 1-800-544-2444. • Outside the US and Canada, call the nearest regional office.
Section 1. Components and Maintenance Locations 1.1 Model KG6208 Engine Side Views 4 3 5 6 2 11 10 8 7 12 9 13 14 15 1 15 21 20 18 23 24 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24.
1.2 Model KG6208 Top and Rear Views 4 1 2 5 16 3 6 7 8 9 15 10 13 14 12 11 3 GM100213 1. Crankcase breather hose 2. Engine bracket 3. Oil dipstick 4. Spark plug wires 5. Coolant temperature sender (only on units with Decision-Maker® 3000) 6. Alternator pulley 7. Drive belt 8. Water pump pulley 9. Drive belt tensioner 10. Coolant temperature sender 11. Positive crankcase ventilation (PCV) valve 12. TMAP sensor1 13. Oil filler cap 14. Engine mounting bracket 15. Flywheel 16.
Section 2. Operation 2.1 Introduction These four-stroke internal combustion engines are certified to operate on either Propane, Liquid Petroleum Gas (LPG) or Natural Gas (NG). System configuration is factory preset for NG. Instructions for switching to LPG are provided within this section. The fuel system on this engine is a closed loop design. As the engine runs, sensors located at various points within the system provide continuous operating feedback to the Engine Control Module (ECM).
Direct Acting Electronic Pressure Regulator Figure 4 Fuel Pressure Regulator The direct acting electronic pressure regulator (DEPR) controls the gaseous fuel pressure and fuel delivery. The DEPR receives fuel pressure commands from the ECM and modulates fuel pressure to the air-fuel mixer. The DEPR allows for fast and accurate gaseous fuel control to provide a combustible mixture to the engine.
Throttle Body Figure 6 Throttle Body The throttle body controls the operating speed of the engine according to input from the ECM. Defaults programmed into the ECM software, along with throttle position sensors, allow the ECM to control the overall operation of the engine in response to changing speeds and loads. Engine Control Module (ECM) Figure 7 Engine Control Module The ECM is a digital controller that oversees the various operating parameters of the engine.
Sensors Air Temperature / Manifold Absolute Pressure (TMAP) Sensor The Air Temperature / Manifold Absolute Pressure (TMAP) sensor monitors the absolute pressure in the intake manifold. This sensor also measures the temperature of the incoming air. Data returned by the TMAP sensor prompts the ECM to adjust the air-fuel mixture as needed. Camshaft Position Sensor The camshaft position sensor measures the rotary speed and camshaft turning angle.
2.2.2 Fuel Specifications Note: The fuel system installation must comply with applicable national, state, and local codes. Fuel Type Liquid Propane Gas (LPG) Natural Gas (NG) LPG and NG (both) Figure 8 TP-7095 Specification Item KG6208 Type HD-5 or HD-10 Maximum fuel pressure (engine OFF, no load) 11.0” W.C. Minimum fuel pressure (engine ON, full load) 5.0” W.C Supply Standard pipeline Approximate supply volume 37.257 kJ/m3 (1000 BTU/ft.3) Minimum flow 42.6 m3/hr. (1504 ft3/hr) @ 6.
2.2.3 Before Starting WARNING Accidental starting. Can cause severe injury or death. Disconnect the battery cables before working on the engine. Remove the negative (–) lead first when disconnecting the battery. Reconnect the negative (–) lead last when reconnecting the battery. Disabling the engine. Accidental starting can cause severe injury or death. Before working on the engine or connected equipment, disable the engine as follows: 1) Disconnect the ignition coil.
2.2.4 Starting The specific engine starting sequence varies depending on the equipment that this engine powers. For more information, refer to the Operation Manual for the equipment using this engine. WARNING Carbon monoxide. Can cause severe nausea, fainting, or death. The exhaust system must be leakproof and routinely inspected. Engine Operation. Carbon monoxide can cause severe nausea, fainting, or death. Engine exhaust gases contain poisonous carbon monoxide.
2.2.5 Cold Weather Starting WARNING Handling caustic engine fluids and chemical products can cause severe chemical burns, nausea, fainting, or death. Most chemicals such as used engine oil, antifreeze/coolant, rustproofing agent, inhibiting oil, degreasing agent, spray paint, and adhesives are hazardous to health. Read and follow the user information found on the packaging. Avoid inhalation and skin contact. Use only in well-ventilated areas and use a protective mask when spraying.
2.2.6 Monitoring Engine Operation WARNING Carbon monoxide. Can cause severe nausea, fainting, or death. The exhaust system must be leakproof and routinely inspected. Engine Operation. Carbon monoxide can cause severe nausea, fainting, or death. Engine exhaust gases contain poisonous carbon monoxide. Carbon monoxide is an odorless, colorless, tasteless, nonirritating gas that can cause death if inhaled for even a short time. Avoid breathing exhaust fumes when working on or near the engine.
TP-7095 4/18
Section 3. Maintenance 3.1 Introduction Preventive maintenance is critical to prolonging the life of the engine and keeping it in optimum working condition. As the engine runs, fasteners may loosen, parts may become worn, clearances change, and oil picks up dirt and contaminants. The engine may eventually become hard to start, or may exhibit other symptoms such as decreased power output or increased fuel consumption.
CAUTION Hazardous voltage. Electrical shock can cause injury. Do not touch wires while the engine is running. Stop the engine and disconnect the battery leads, negative (-) lead first, before servicing the engine. Servicing the engine when it is operating. Exposed moving parts will cause severe injury or death. Keep hands, feet, hair, clothing, and test leads away from the belts and pulleys when the engine is running. Replace guards, screens, and covers before operating the engine. WARNING Moving parts.
3.3 Fluid Specifications 3.3.1 Oil Recommendations Kohler recommends Kohler Genuine Oil, 10W-40 or equivalent. Kohler Genuine Oil is fully synthetic and engineered specifically for gaseous-fueled (NG/LPG) engines requiring SAE 10W-40 oil. The oil must meet the specifications for zinc, phosphorus and ash content listed in Figure 9. Oil Specifications Oil Type Kohler Genuine Oil, 10W-40 Zinc 1000-1200 ppm Phosphorous 1000-1200 ppm Sulfate Ash Content Figure 9 1.
3.4 Periodic Maintenance Schedule Engine parts experience wear at different rates. Technical maintenance tasks, therefore, are required at different intervals throughout the life of the engine. Tasks performed after the first 10 hours of operation, for example, must be repeated after 20 hours, 30 hours, and so forth. Perform and repeat these tasks according to the periodic schedule below. Daily (Before Starting) Check the engine oil level and replenish as needed.
3.5 Engine 3.5.1 Check Engine Oil Check the engine oil level daily before starting the engine. Inspect the oil for signs of deterioration, discoloration, thinning, or water contamination. If any of these conditions exist, the oil quality has been compromised and should be replaced. Required materials: • Clean, dry cloth. • Fresh engine oil. (See the section “Oil Recommendations”) Procedure: 1. Stop the engine and allow it to cool. 2. Pull out the oil dipstick. See Figure 10.
Oil fill cap Figure 12 3.5.2 Oil Fill Cap Change Engine Oil and Oil Filter Change the engine oil and filter every 150 hours of operation. Replace the engine oil and filter more often if the machine is being run in excessively dirty or dusty conditions. WARNING Accidental starting. Can cause severe injury or death. Disconnect the battery cables before working on the engine. Remove the negative (–) lead first when disconnecting the battery.
WARNING Explosive fuel can cause fires and severe burns. If a gaseous odor is detected, ventilate the area and contact an authorized service technician. The fuel system. Explosive fuel vapors can cause severe injury or death. Vaporized fuels are highly explosive. Use extreme care when handling and storing fuels. Store fuels in a well-ventilated area away from spark-producing equipment and out of the reach of children.
Change the engine oil and oil filter: 1. Stop the engine and allow it to cool. 2. Place a drop cloth and collection container beneath the oil drain valve. See Figure 13. Oil filler cap Oil drain valve Figure 13 Oil Fill and Drain Valve Location 3. Open the oil drain valve and allow the oil to drain into the container. 4. Using an oil filter wrench, remove the old oil filter. 5. Wipe the oil filter installation surface clean with a dry cloth. Inspect the installation surface for damage.
12. Start and run the engine without load for approximately 5 minutes. This will ensure that the fresh engine oil is distributed to each friction surface. Note: Dispose of used engine oil and oil filters in accordance with local environmental regulations. Full mark Add mark Figure 15 3.5.3 Oil Dipstick Check and Clean the Air Filter Refer to the Operation Manual for the equipment using this engine. 3.5.4 Replace the Air Filter Refer to the Operation Manual for the equipment using this engine. 3.
Procedure: 1. Stop the engine and allow it to cool. Note: Label or mark spark plug wires before disconnecting. Spark plug wires must be reconnected in the same order as removed. 2. Use a cloth to wipe dirt and oil away from the area around each of the four spark plug wires. See Figure 16. Spark plug wires Figure 16 Spark Plug Wires 3. Disconnect the spark plug wires. 4. Use a spark plug wrench to remove the spark plugs. 5.
Spark plug gap Figure 18 Spark Plug Gap 8. Thread the spark plugs into the cylinder head. 9. Tighten the spark plugs to specification. Spark Plug Torque KG6208 10. 3.5.6 27 Nm (20 ft. lb.) Reconnect the spark plug wires to the spark plugs. Ignition Timing The ignition system consists of a distributor and an ignition coil which provide voltage to the spark plugs. The ECM uses information from the camshaft and crankshaft position sensors to optimize ignition timing.
3.6 Electrical System 3.6.1 Check Battery and Connections WARNING Sulfuric acid in batteries. Can cause severe injury or death. Wear protective goggles and clothing. Battery acid may cause blindness and burn skin. WARNING Explosion. Can cause severe injury or death. Relays in the battery charger cause arcs or sparks. Locate the battery in a well‐ventilated area. Isolate the battery charger from explosive fumes. Battery electrolyte is a diluted sulfuric acid.
3.6.2 Check and Adjust the Drive Belt A worn, stretched, or damaged drive belt may fail, especially under heavy loads. Check the condition of the drive belt regularly and adjust belt tension as needed. WARNING Accidental starting. Can cause severe injury or death. Disconnect the battery cables before working on the engine. Remove the negative (–) lead first when disconnecting the battery. Reconnect the negative (–) lead last when reconnecting the battery. Disabling the engine.
Check drive belt condition: 1. Stop the engine and allow it to cool. 2. Locate the drive belt. See Figure 19. Drive belt Figure 19 3. Inspect the drive belt. Look for signs of cracking, separation, cuts, or other damage. See Figure 20. 4. If any abnormality is found, replace the drive belt.
3.6.3 Replace the Drive Belt WARNING Accidental starting. Can cause severe injury or death. Disconnect the battery cables before working on the engine. Remove the negative (–) lead first when disconnecting the battery. Reconnect the negative (–) lead last when reconnecting the battery. Disabling the engine. Accidental starting can cause severe injury or death. Before working on the engine or connected equipment, disable the engine as follows: 1) Disconnect the ignition coil.
Alternator pulley Tensioner pulley Water pump pulley Crank pulley Figure 22 Drive Belt Diagram 4. While using the socket wrench to turn the tensioner pulley clockwise, slip the belt around the tensioner pulley. Release the tensioner. 5. Make sure that the belt is properly aligned with the grooves on each pulley. See Figure 23. Incorrect Correct Figure 23 3.6.4 Belt Alignment Check Wiring and Electrical Connections CAUTION Hazardous voltage. Electrical shock can cause injury.
3.7 Cooling System WARNING 3.7.1 Hot coolant and steam. Can cause severe injury or death. Before removing the pressure cap, stop the engine and allow it to cool. Then loosen the pressure cap to relieve pressure. Check Coolant Level and Condition The engine coolant level should be checked daily before starting the engine. Insufficient coolant will cause the engine to overheat. 1. Open the radiator cap slowly in order to release the pressure in the system. 2.
3.8 Fuel System WARNING Explosive fuel vapors. Can cause severe injury or death. Use extreme care when handling, storing, and using fuels. The fuel system. Explosive fuel vapors can cause severe injury or death. Vaporized fuels are highly explosive. Use extreme care when handling and storing fuels. Store fuels in a well-ventilated area away from spark-producing equipment and out of the reach of children.
Section 4. Troubleshooting 4.1 Introduction The following chart will help you to identify and solve some of the basic operating problems that may occur while operating this engine. Do not attempt to service or replace major engine components, or any items that require special timing or adjustment procedures. This work should be performed only by a Kohler authorized distributor/dealer. 4.2 Troubleshooting Problem Will Not Start Possible Cause Check fuel supply.
Problem Possible Cause Solution Incorrect fuel Make sure fuel system is configured properly for LPG or NG supply. Engine overloaded Disconnect or reduce loads. Faulty spark plug or wire Inspect, adjust, or replace as needed. Dirty/restricted fuel system Check fuel system and clean components as needed. Dirty air filter Inspect and replace as needed. Boost pressure too high (if applicable) Check for stuck wastegate, check for leak in wastegate boost line (if applicable).
Section 5. Storage 5.1 WARNING Hot engine and exhaust system. Can cause severe injury or death. Do not work on the engine until it cools. WARNING Moving parts. Can cause severe injury or death. Operate the engine only when all guards and electrical enclosures are in place. Stay away from moving parts while the engine is in operation. CAUTION Hazardous voltage. Electrical shock can cause injury. Do not touch wires while the engine is running.
5.3 Long-Term Storage (More than 30 Days) In addition to the short-term tasks, perform the following tasks before placing the engine in storage: • Change the engine oil and filter. • Remove the drive belt. • Protect the cylinders from rust: o Disconnect the spark plug wires and remove the spark plugs. o Squirt approximately 30 ml (1 ounce) of fresh engine oil into each cylinder. o Manually rotate the crankshaft 10–15 times to distribute the oil evenly in the cylinders.
Section 6. Specifications 6.1 Engine Specifications Item Specifications Engine Model Block Type KG6208 V-8 Number of Cylinders 8 Cylinder Bore 101.6 mm (4 in.) Piston Stroke 95.25 mm (3.75 in.) Displacement 6.2 L (377 in.3) Rated Output @ 1800 rpm 75.0 kW (100.6 hp), NG 77.0 kW (103.3 hp), LPG Fuel Type Propane, Liquid Petroleum Gas (LPG) or Natural Gas (NG). See “Fuel Specifications.” Oil Type / Weight Kohler recommends Rotella® T4 15W40 or equivalent.
6.2 Main Components Specifications Specifications Item KG6208 Oil Filter/ Breather Paper, Rocker arm covers, Top oil filter Oil Pump Gear type Water Pump Centrifugal type; no fan Flywheel Flywheel with attachment provisions for flywheel adapter Thermostat Settings, Fully Open at 71°C (160°F) Alternator Rated voltage 14 V, rated current 130 A Electric Starter 1.
6.5 Standard Torque Specifications American Standard Fasteners Torque Specifications Assembled into Cast Iron or Steel Size Torque Measurement Grade 2 Grade 5 Grade 8 8-32 Nm (in. lb.) 1.8 (16) 2.3 (20) - 10-24 Nm (in. lb.) 2.9 (26) 3.6 (32) - 10-32 Nm (in. lb.) 2.9 (26) 3.6 (32) - 1/4-20 Nm (in. lb.) 6.8 (60) 10.8 (96) 14.9 (132) 1/4-28 Nm (in. lb.) 8.1 (72) 12.2 (108) 16.3 (144) 5/16-18 Nm (in. lb.) 13.6 (120) 21.7 (192) 29.8 (264) 5/16-24 Nm (in. lb.) 14.
TP-7095 4/18
TP-7095 4/18a © 2018 by Kohler Co. All rights reserved. KOHLER CO. Kohler, Wisconsin 53044 Phone 920-457-4441, Fax 920-459-1646 For the nearest sales/service outlet in the US and Canada, phone 1-800-544-2444 KOHLERPower.
