40
Troubleshooting
Problem: Engine will not start or is hard to start (Compression too low)
Condition
Remedy
1.
Gasoline
bad - contaminated
2.
Valve clearance
out of adjustment
3.
Valve guides
worn
4.
Valves
mistimed
5.
Piston rings
worn - broken
6.
Cylinder bore
worn
7.
Starter motor
cranks too slowly - does not turn
1. Drain gas - replace with clean gas
2. Adjust clearance
3. Replace cylinder head
4. Retime engine
5. Replace rings
6. Replace cylinder
7. See Electrical System
Problem: Engine will not start or is hard to start (No spark)
Condition
Remedy
1.
Spark plug(s)
fouled
2.
Spark plug(s)
wet
3.
Magneto
defective
4.
ECM
defective
5.
Ignition coil
defective
6.
High-tension lead open
- shorted
1. Clean - replace plug(s)
2. Clean - dry plug(s)
3. Replace stator coil
4. Replace ECM
5. Replace ignition coil
6. Replace high tension lead
Problem: Engine will not start or is hard to start (No fuel reaching the fuel injector)
Condition
Remedy
1.
Gas tank vent hose
obstructed
2.
Fuel hose
obstructed
3.
Fuel screens
obstructed
4.
Fuel pump
defective
1. Clean vent hose
2. Clean - replace hose
3. Clean - replace inlet screen
4. Replace fuel pump
Problem: Engine stalls easily
Condition
Remedy
1.
Gasoline
bad - contaminated
2.
Spark plug(s)
fouled
3.
Magneto
defective
4.
ECM
defective
5.
Fuel injector
obstructed
6.
Valve clearance
out of adjustment
1. Drain gas - replace with clean gas
2. Clean - replace plug(s)
3. Replace stator coil
4. Replace ECM
5. Replace fuel injector
6. Adjust clearance
Problem: Engine noisy (Excessive valve chatter)
Condition
Remedy
1.
Valve clearance
excessive
2.
Valve spring(s)
weak - broken
3.
Camshaft
worn
1. Adjust clearance
2. Replace spring(s)
3. Replace camshaft
Problem: Engine noisy (Noise seems to come from piston)
Condition
Remedy
1.
Piston - cylinder
worn
2.
Combustion chamber
carbon buildup
3.
Piston pin - piston pin bore
worn
4.
Piston rings - ring groove(s)
worn
1. Replace - service piston - cylinder
2. Clean cylinder head and piston
3. Replace - service pin - replace connecting rod
4. Replace rings - piston
Problem: Engine noisy (Noise seems to come from timing chain)
Condition
Remedy
1.
Chain
stretched
2.
Sprockets
worn
3.
Tension adjuster
malfunctioning
1. Replace chain
2. Replace sprockets
3. Repair - replace adjuster
Problem: Engine noisy (Noise seems to come from crankshaft)
Condition
Remedy
1.
Main bearing
worn - burned
2.
Lower rod-end bearing
worn - burned
3.
Rotor/flywheel
loose
1. Replace bearing
2. Replace bearing
3. Tighten - replace flywheel - crankshaft
Problem: Engine noisy (Noise seems to come from crankcase)
Condition
Remedy
1.
Gears
worn - chipped
2.
Splines
worn
3.
Bearings
worn
4.
Bushing
worn
1. Replace gears
2. Replace shaft(s)
3. Replace bearings
4. Replace bushing