Troubleshooting; Engine - Suzuki DR-Z70 Service Manual

TROUBLESHOOTING

ENGINE

Complaint
Engine will not Compression too low
start, or is hard to
start.
Plugs not sparking
No fuel reaching the carburetors
Engine stalls often.
Noisy engine. Excessive valve chatter
Noise seems to come from piston
Symptom and possible causes
1. Valve clearance out of adjustment.
2. Worn valve guides or poor seating of valves.
3. Mistiming valves.
4. Excessively worn piston rings.
5. Worn-down cylinder bore.
6. Too slowly starter motor cranks.
7. Poor seating of spark plug.
8. Gas leaks from the joint in crankcase, cylinder or
cylinder head.
1. Fouled spark plug.
2. Wet spark plug.
3. Defective ignition coil.
4. Open or short in high-tension cord.
5. Defective pick-up coil or CDI unit.
6. Open or short circuited wiring connections.
1. Clogged hole in the fuel tank cap.
2. Defective carburetor needle valve.
3. Clogged fuel hose or fuel filter.
1. Fouled spark plug.
2. Defective pick-up coil or CDI unit.
3. Clogged fuel hose or fuel tank cap.
4. Clogged jets in carburetor.
5. Valve clearance out of adjustment.
6. Clogged exhaust pipe.
7. Open or short circuited wiring connection.
1. Too large valve clearance.
2. Weakened or broken valve springs.
3. Worn rocker arm or cam surface.
4. Worn or burnt camshaft bearings.
1. Worn down piston or cylinder.
2. Combustion chamber fouled with carbon.
3. Worn piston pin or piston pin bore.
4. Worn piston rings or ring grooves.
SERVICING INFORMATION
Remedy
Adjust.
Repair or replace.
Adjust.
Replace.
Replace or rebore.
See electrical section.
Retighten.
Repair or replace.
Clean.
Clean and dry.
Replace.
Replace.
Replace.
Repair or replace.
Clean or replace.
Replace.
Clean or replace.
Clean.
Replace.
Clean or replace.
Clean.
Adjust.
Clean.
Repair or replace.
Adjust.
Replace.
Replace.
Replace.
Replace.
Clean.
Replace.
Replace.
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