20
Troubleshooting
Problem: Engine will not start or is hard to start (Compression too low)
Condition
Remedy
1.
Valve clearance
out of adjustment
2.
Valve guides
worn
3.
Valves
mistimed
4.
Piston rings
worn - broken
5.
Cylinder bore
worn
6.
Starter motor
cranks too slowly - does not turn
1. Adjust clearance
2. Repair - replace guides
3. Retime engine
4. Replace rings
5. Replace cylinder
6. 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.
Spark plug(s)
fouled
2.
Magneto
defective
3.
ECM
defective
4.
Fuel injector
obstructed
5.
Valve clearance
out of adjustment
1. Clean - replace plug(s)
2. Replace stator coil
3. Replace ECM
4. Replace fuel injector
5. Adjust clearance
Problem: Engine noisy (Excessive valve chatter)
Condition
Remedy
1.
Valve clearance
excessive
2.
Valve spring(s)
weak - broken
3.
Rocker arm
-
rocker arm shaft
worn
4.
Camshaft
worn
1. Adjust clearance
2. Replace spring(s)
3. Replace arm - shaft
4. 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 - bore
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.
Connecting rod side clearance
too large
4.
Centrifugal clutch
loose
5.
Rotor/flywheel
loose
1. Replace bearing
2. Replace crankshaft assembly
3. Replace crankshaft assembly
4. Tighten - replace clutch
5. Tighten - replace flywheel - crankshaft
Problem: Engine noisy (Noise seems to come from transmission)
Condition
Remedy
1.
Gears
worn - chipped
2.
Splines
worn
3.
Primary gears
worn - chipped
4.
Bearings
worn
5.
Bushing
worn
1. Replace gears
2. Replace shaft(s)
3. Replace gears
4. Replace bearings
5. Replace bushing