Suzuki DR 125, Service Manual

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7-4 SERVICING INFORMATION
Complaint Symptom and possible causes Remedy
Transmission jumps
out of gear. 1. Worn gear.
2. Worn or distorted gearshift fork.
3. Weakened gearshift stopper spring.
4. Worn gearshift pawl. Replace.
Replace.
Replace.
Replace.
Engine idles poorly. 1. Valve clearance out of adjustment.
2. Improper valve seating.
3. Worn valve guide.
4. Worn camshaft.
5. Excessive spark plug gap.
6. Defective ignition coil.
7. Defective generator.
8. Defective CDI unit.
9. Incorrect float chamber fuel level.
10. Clogged carburetor jet.
Adjust.
Repair or replace.
Replace.
Replace.
Adjust or replace.
Replace.
Replace.
Replace.
Adjust float height.
Clean.
Engine runs poorly in
high-speed range. 1. Weak valve spring.
2. Worn camshaft.
3. Insufficient spark plug gap.
4. Mistimed valves.
5. Ignition not advanced sufficiently due to poorly working
timing advance circuit.
6. Defective ignition coil.
7. Defective generator.
8. Defective CDI unit.
9. Low float chamber fuel level.
10. Dirty air cleaner element.
11. Clogged fuel hose, resulting in inadequate fuel supply
to carburetor.
Replace.
Replace.
Regap or replace.
Adjust.
Replace CDI unit.
Replace.
Replace.
Replace.
Adjust float height.
Clean or replace.
Clean and prime.
Exhaust smoke is
dirty or thick. 1. Excessive amount of engine oil.
2. Worn cylinder.
3. Worn piston ring.
4. Worn valve guide.
5. Scored or scuffed cylinder wall.
6. Worn valve stem.
7. Defective valve stem oil seal.
8. Worn oil ring side rail.
C heck level and drain.
Replace.
Replace.
Replace.
Replace.
Replace valve.
Replace.
Replace oil ring.
Engine lacks power. 1.
Insufficient
valve clearance.
2. Weak valve spring.
3. Mistimed valves.
4. Worn cylinder.
5. Worn piston ring.
6. Improper valve seating.
7. Fouled spark plug.
8. Incorrect spark plug.
9. Clogged carburetor jet.
10. Incorrect float chamber fuel level.
11. Dirty air cleaner element.
12. Air leakage from intake pipe.
13. Excessive amount of engine oil.
Adjust.
Replace.
Adjust.
Replace.
Replace.
Repair or replace.
Clean or replace.
Replace.
Clean.
Adjust float height.
Clean or replace.
Tighten or replace.
C
heck level and drain.