ENGINE TROUBLESHOOTING
ENGINE—KOHLER
Engine Has Low Power Is engine overheated?
YES NO
Is lubricating condition normal?
NO YES
Is black or blue smoke emitted out of muffler?
YES
NO
Is compression sufficient?
NO
• Excessive engine load. • Carburetor not properly adjusted (too lean). • Dirty or clogged air intake screen, shroud and engine fins. • Carbon deposit in combustion chamber. • Incorrect oil level.
Adjust load Adjust Clean
• Too much or too little oil in crankcase. • Excessively contaminated lubricating oil/filter. • Faulty oil pump.
Correct Change Replace
• Air cleaner clogged. • Carbon deposit in exhaust port and muffler. • Carburetor not properly adjusted. • Too much oil in crankcase. • Stale fuel.
Clean Clean Adjust Correct Fresh fuel
• Worn piston/piston rings. • Stuck piston rings.
Replace Clean or replace
• Worn cylinder bore.
Bore or replace Lap or grind Adjust
• Faulty contact of valve seat. • Misadjusted valves. • Warped cylinder head. • Broken valve spring. • Stuck valve. • Leaking head gasket.
Clean Adjust
Repair or replace Replace Clean or grind Replace
Fuel Consumption Is Excessive Is compression sufficient?
YES
NO
• Carburetor float or pilot air screw not properly adjusted. • Air cleaner clogged. • Fast idle speed excessive (too high). • Choke valve not fully open. • Leak in fuel system.
Adjust Clean Adjust Adjust Correct
• See Engine Has Low Power—Is compression sufficient? - NO, above.
3 - 14
3/6/02