Suzuki AN650 2002 Service Manual page 410

11-6 SERVICING INFORMATION
Complaint
Noisy engine.
Engine runs poorly in
high speed range.
Symptom and possible causes
Excessive valve chatter
1. Too large tappet clearance.
2. Weakened or broken valve springs.
3. Worn tappet or cam surface.
4. Worn and burnt camshaft journal.
Noise seems to come from piston
1. Worn down pistons or cylinders.
2. Combustion chambers fouled with carbon.
3. Worn piston pins or piston pin bore.
4. Worn piston rings or ring grooves.
Noise seems to come from timing chain
1. Stretched chain.
2. Worn sprockets.
3. Tension adjuster not working.
Noise seems to come from clutch
1. Worn splines of countershaft or hub.
2. Worn teeth of clutch plates.
3. Distorted clutch plates, driven and drive.
4. Worn clutch release bearing.
5. Weakened clutch dampers.
Noise seems to come from crankshaft
1. Rattling bearings due to wear.
2. Worn and burnt big-end bearings.
3. Worn and burnt journal bearings.
4. Too large thrust clearance.
Noise seems to come from transmission
1. Worn or rubbing gears.
2. Worn splines.
3. Worn or rubbing primary gears.
4. Worn bearings.
Noise seems to come from water pump
1. Too much play on pump shaft bearing.
2. Worn or damaged impeller shaft.
3. Worn or damaged mechanical seal.
4. Contact between pump case and impeller.
Defective engine internal/electrical parts
1. Weakened valve springs.
2. Worn camshafts.
3. Valve timing out of adjustment.
4. Too narrow spark plug gaps.
5. Ignition not advanced sufficiently due to poorly working
timing advance circuit.
6. Defective ignition coil.
7. Defective crankshaft position sensor.
8. Defective ECM.
9. Clogged air cleaner element.
10. Clogged fuel hose, resulting in inadequate fuel supply
to injector.
11. Defective fuel pump.
12. Defective throttle position sensor.
Remedy
Adjust.
Replace.
Replace.
Replace.
Replace.
Clean.
Replace.
Replace.
Replace.
Replace.
Repair or replace.
Replace.
Replace.
Replace.
Replace.
Replace the primary driven
gear.
Replace.
Replace.
Replace.
Replace thrust bearing.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Adjust.
Adjust.
Replace ECM.
Replace.
Replace.
Replace.
Clean.
Clean and prime.
Replace.
Replace.