7-2 SERVICING INFORMATION
TROUBLESHOOTING
ENGINE
Complaint Symptom and possible causes Remedy
Engine will not start or
is hard to start.
Compression too low
1. Worn cylinder.
2. Worn piston ring.
3. Worn valve guide or improper valve seating.
4. Loose spark plug.
5. Broken, cracked or damaged piston.
6. Slow cranking starter motor.
7. Mistimed valves.
8. Valve clearance out of adjustment.
Spark plug not sparking
1. Damaged spark plug.
2. Damaged spark plug cap.
3. Fouled spark plug.
4. Wet spark plug.
5. Defective ignition coil.
6. Open or short in high-tension cord.
7. Defective signal generator.
8. Defective ignitor.
No fuel reaching a carburetor
1. Clogged fuel tank vent hose.
2. Clogged or defective fuel valve.
3. Defective needle valve.
4. Clogged fuel hose.
5. Clogged fuel filter.
Rebore or replace.
Replace.
Repair or replace.
Tighten.
Replace.
See electrical section.
Adjust.
Adjust.
Replace.
Replace.
Clean or replace.
Clean and dry or replace.
Replace.
Replace.
Replace.
Replace.
Clean or replace.
Clean or replace.
Replace with needle
valve seat.
Clean or replace.
Clean or replace.
Engine stalls easily. 1. Fouled spark plug.
2. Defective signal generator.
3. Defective ignitor.
4. Clogged fuel hose.
5. Clogged carburetor jet.
6. Valve clearance out of adjustment.
Clean or replace.
Replace.
Replace.
Clean.
Clean.
Adjust.