Kohler CH740S Troubleshooting
| Engine Model: Kohler Command CH740S |
| Engine Type: 4-cycle V-Twin cylinder horizontal shaft air-cooled gasoline |
| Total Displacement: 44 cu.in (725 cc) |
| Rated Engine Power: 25 Hp (18.6 kW) at 3600 rpm |
| Carburetor Type: One-barrel with fixed main jet |
____________________________________________________________________________________
| Engine difficult to start or won't start |
Gas tank is empty - Add gasoline.
Wrong grade of gasoline - Use quality fuel.
Air trapped in fuel system - Bleed air.
Faulty spark plug wire connection - Inspect the spark plug wire connection, replace or repair.
Spark plug is damaged - Replace spark plug.
Dirty fuel filter - Replace fuel filter.
Defective safety switch - Replace if required.
Carburetor malfunction - Check and repair as required.
Engine has low compression - Check cylinder block and replace defective parts.
Choke cable is worn or not adjusted properly - Change cable or adjust properly.
Air intake screen is plugged - Need to clean or wash.
Defective ignition - Inspect ignition system and change failed components.
Choke cable is stuck or defective - Clean or replace the cable.
Plugged air filter - Service or replace air filter.
Dirty or faulty fuel pump - Clean or replace fuel pump.
| Engine starts and then shuts off |
Spark plug is faulty - Install new spark plug.
Dirty or defective carburetor - Service or replace carburetor.
Ignition coil is damaged - Change ignition coil as required.
Valve springs are worn or loose - New valve springs need to be installed.
Valves are stuck - Clean the valves.
Engine oil level low - Check oil level and add oil as required.
Engine is overloaded - Reduce engine load.
Cooling fins are plugged - Need to clean or wash.
Too lean carburetor mixture - Make the correct settings.
Incorrect ignition timing - Set the ignition timing correctly.
Valve setting is improper - Set the valves correctly.
| Abnormal engine knocking or noise |
Stale or low octane fuel - Use correct gasoline.
Engine is running overloaded - Load reducing required.
Engine oil insufficient - Check and refill engine oil.
Improperly adjusted low idle speed - Correct the settings.
Dirty or damaged fuel pump - Service or replace fuel pump.
Main bearings or crankshaft are worn out - Worn parts replacement required.
Valve clearance is wrong - Adjust valve clearance.
Cylinder bore or piston rings are worn - Replace faulty components.
Improperly adjusted or dirty carburetor - Service or properly adjust carburetor.
Plugged air filter - Service or change air filter.
Dirty or faulty fuel pump - Test fuel pump and replace if necessary.
Ignition system is defective - Check ignition and replace faulty components.
Blown cylinder head gasket - Cylinder-head gasket replacement required.
Valves are burned or stuck - Clean or replace valves.
Push rod is bent or worn - Replace push rod.
Cylinder block components are worn - Change defective parts.
Oil filter element is plugged (if equipped) - Change or clean oil filter.
| Engine using too much gasoline |
Choke did not open fully - Change or adjust choke cable.
Improper carburetor main jet adjustment - Adjust the carburetor main jet correctly.
Loose or defective spark plug - Tighten or change the spark plug.
Stuck, burned, or worn valves - Replace or service valves.
Worn sleeve, piston, or rings - Replace defective components.
Valve clearance is wrong - Check and adjust.
| Engine using too much oil |
Gaskets or seals may be damaged - Replace to repair leaks.
Valve guides or stems are damaged - Replace the valves.
Damaged or seized piston rings - Have piston rings replaced.
Piston or cylinder liner is scuffed - Check piston and liner, install new parts as required.
Clogged breather hose or pipe - Clean or change.
____________________________________________________________________________________
| Small Engines Technical Specifications |
| Car Engines Technical Specifications |
| Outboard Engines Technical Specifications |
| Industrial Engines Technical Specifications |
