33
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.
Valve
timing incorrect
4.
Piston rings
worn excessively
5.
Cylinder bore
worn
6.
Spark plug
seating poorly
7.
Starter motor
cranks too slowly - does not turn
1. Adjust clearance
2. Replace cylinder head
3. Correct valve timing - check chain, sprockets, and cam chain
tensioner
4. Replace rings
5. Replace cylinder
6. Tighten plug
7. Check - replace starter motor
Problem: Engine will not start or is hard to start (No spark)
Condition
Remedy
1.
Spark plug
fouled
2.
Spark plug
wet
3.
Magneto
defective
4.
CDI unit
defective
5.
Ignition coil
defective
6.
High-tension lead
open - shorted
1. Clean - replace plug
2. Clean - dry plug
3. Replace stator coil
4. Replace CDI unit
5. Replace ignition coil
6. Replace high tension lead
Problem: Engine will not start or is hard to start (No fuel reaching the carburetor
Condition
Remedy
1.
Gas tank vent hose
obstructed
2.
Fuel hose
obstructed
3.
Fuel screens
obstructed
4.
Carburetor float valve
defective
1. Clean vent hose
2. Clean - replace hose
3. Clean - replace inlet screen - valve screen
4. Replace valve
Problem: Engine stalls easily
Condition
Remedy
1.
Spark plug
fouled
2.
Magneto
defective
3.
CDI unit
defective
4.
Valve clearance
out of adjustment
5.
Carburetor jets
obstructed
1. Clean plug
2. Replace stator coil
3. Replace CDI unit
4. Adjust clearance
5. Clean jets
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
5.
Valve tappets
worn
1. Adjust clearance
2. Replace spring(s)
3. Replace arm - shaft
4. Replace camshaft
5. Replace tappets
Problem: Engine noisy (Noise seems to come from piston)
Condition
Remedy
1.
Piston - cylinder
worn
2.
Combustion chamber
carbon buildup
3.
Piston pin bore
worn
4.
Piston pin
worn
5.
Piston rings - ring groove(s)
worn
1. Replace - service piston - cylinder
2. Clean chamber
3. Replace piston
4. Replace piston pin
5. 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.
Bearing
worn - burned
2.
Lower rod-end bearing
worn - burned
3.
Connecting rod side clearance
too large
1. Replace bearing
2. Replace crankshaft
3. Replace crankshaft