Harbor Freight Tools 68122 - Manual (Page 16)

Page 16 For technical questions, please call 1-800-520-0882. Vertical Engine
Problem Possible Causes Probable Solutions
Engine misfires 1. Spark plug cap loose.
2. Incorrect spark plug gap or
damaged spark plug.
3. Defective spark plug cap.
4. Old or low quality gasoline.
5. Incorrect compression.
1. Check wire connections.
2. Re-gap or replace spark plug.
3. Replace spark plug cap.
4. Use only fresh 87+ octane unleaded gasoline.
5. Diagnose and repair compression.
(Use Engine will not start:
COMPRESSION RELATED section.)
Engine stops
suddenly
1. Low oil shutdown.
2. Fuel tank empty or full of impure
or low quality gasoline.
3. Defective fuel tank cap creating
vacuum, preventing proper fuel flow.
4. Faulty magneto.
5. Disconnected or improperly
connected spark plug cap.
1. Fill engine oil to proper level. Check
engine oil before EVERY use.
2. Fill fuel tank with fresh 87+
octane unleaded gasoline.
3. Test/replace fuel tank cap.
4. Have qualified technician service magneto.
5. Secure spark plug cap.
Engine stops when
under heavy load
1. Dirty air filter
2. Engine running cold. 1. Clean or replace element.
2. Allow engine to warm up prior
to operating equipment.
Engine knocks 1. Old or low quality gasoline.
2. Engine overloaded.
3. Incorrect spark timing, deposit
buildup, worn engine, or other
mechanical problems.
1. Fill fuel tank with fresh 87+
octane unleaded gasoline.
2. Do not exceed equipment’s load rating.
3. Have qualified technician diagnose
and service engine.
Engine backfires 1. Impure or low quality gasoline.
2. Engine too cold.
3. Intake valve stuck or overheated engine.
4. Incorrect timing.
1. Fill fuel tank with fresh 87+
octane unleaded gasoline.
2. Use cold weather fuel and oil
additives to prevent backfiring.
3. Have qualified technician diagnose
and service engine.
4. Check engine timing.
Follow all safety precautions whenever diagnosing or servicing the equipment or engine.