Suzuki TU250X Service Manual page 324

10-4 SERVICING INFORMATION
Complaint
Noisy engine
Symptom and possible causes
Excessive valve chatter
1. Too large valve clearance
2. Weakened or broken valve springs
3. Worn rocker arms or cam surfaces
4. Worn and burnt camshaft journal bearings
Noise seems to come from piston
1. Worn down piston or cylinder
2. Carbon combustion chamber fouled with carbon
3. Worn piston pin 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
Noise seems to come from crankshaft
1. Rattling bearings due to wear
2. Worn and burnt big-end bearing
3. Worn and burnt journal bearings
4. Too large thrust clearance
Noise seems to come from balancer
1. Weakened balancer driven gear springs
Noise seems to come from transmission
1. Worn or rubbing gears
2. Worn splines
3. Worn or rubbing primary gears
4. Worn bearings
Remedy
Adjust.
Replace.
Replace.
Replace.
Replace.
Clean.
Replace.
Replace.
Replace.
Replace.
Repair or replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.