7-2
SERVICING INFORMATION
TROUBLESHOOTING
ENGINE
Complaint
Symptom and possible causes
Remedy
Engine will not
Compression too low
start, or is hard to
1. Worn cylinder.
Rebore or replace.
start.
2. Worn piston ring.
Replace.
3. Stiff piston ring.
Repair or replace.
4. Gas leaks from the joint in crankcase, cylinder or
Repair or replace.
cylinder head.
5. Loose spark plug.
Tighten.
6. Broken, cracked or damaged piston.
Replace.
Spark plug not sparking
1. Damaged spark plug.
Replace.
2. Damaged spark plug cap.
Replace.
3. Fouled spark plug.
Clean or replace.
4. Wet spark plug.
Clean and dry or replace.
5. Defective CDI/ignition coil unit.
Replace.
6. Open or short in high-tension cord.
Replace.
7. Defective generator coil.
Replace.
No fuel reaching the carburetor
1. Clogged fuel tank vent hose.
Clean or replace.
2. Clogged or defective fuel valve.
Clean or replace.
3. Defective carburetor needle valve.
Replace.
4. Clogged fuel hose.
Clean or replace.
5. Clogged fuel filter.
Clean or replace.
Engine stalls easily.
1. Fouled spark plug.
Clean or replace.
2. Defective CDI/Ignition coil unit.
Replace.
3. Clogged fuel hose.
Clean.
4. Clogged carburetor jets.
Clean.
5. Clogged exhaust pipe.
Clean.
6. Damaged cylinder head gasket.
Replace.
Engine is noisy.
Noise seems to come from the piston
1. Worn down piston.
Replace.
2. Worn cylinder.
Replace.
3. Carbon built-up in the combustion chamber.
Clean.
4. Worn piston pin, bearing or piston pin bore.
Replace.
5. Worn piston rings or ring grooves.
Replace.
Noise seems to come from the clutch
1. Weak clutch shoe spring.
Replace.
Noise seems to come from the crankshaft
1. Worn or burnt crank pin bearing.
Repalce.
2. Worn or burnt crankshaft bearing.
Replace.
Clutch slips.
1. Worn or damaged clutch shoe.
Replace.
2. Worn clutch drum.
Replace.
