Troubleshooting; Engine - Suzuki DR 125 Service Manual

7-2 SERVICING INFORMATION

TROUBLESHOOTING

ENGINE

Complaint
Engine will not start
or is hard to start.
Engine stalls easily.
Symptom and possible causes
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. Mistimed valves.
7. 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 generator.
8. Defective CDI unit.
No fuel reaching the carburetor
1. Clogged fuel tank vent hose.
2. Clogged or defective fuel valve.
3. Defective carburetor needle valve.
4. Clogged fuel hose.
5. Clogged fuel filter.
1. Fouled spark plug.
2. Defective generator.
3. Defective CDI unit.
4. Clogged or defective fuel valve.
5. Clogged carburetor jet.
6. Valve clearance out of adjustment.
Remedy
Replace.
Replace.
Repair or replace.
Tighten.
Replace.
Adjust.
Adjust.
Replace.
Replace.
Clean or replace.
Clean and dry or replace.
Replace.
Replace.
Replace.
Replace.
Clean or replace.
Clean or replace.
Replace.
Clean or replace.
Clean or replace.
Clean or replace.
Replace.
Replace.
Clean or replace.
Clean.
Adjust.