Suzuki UF50, Service Manual

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SERVICING INFORMATION 7-3
Complaint Symptom and possible causes Remedy
Engine idles poorly. 1. Worn cylinder.
2. Worn piston rings.
3. Stiff piston ring.
4. Gas leaks from crankshaft oil seal.
5. Excessive spark plug gap.
6. Defective ignition coil.
7. Defective CDI unit.
8. Defective stator coil.
9. Incorrect float chamber fuel level.
10. Clogged carburetor jet.
11. Broken or damaged reed valve.
Replace.
Replace.
Replace.
Replace.
Adjust or replace.
Replace.
Replace.
Replace.
Adjust float height.
Clean.
Replace.
Engine runs poorly in
high-speed range. 1. Worn cylinder.
2. Worn piston rings.
3. Stiff piston ring.
4. Insufficient spark plug gap.
5. Ignition not advanced sufficiently due to poorly work-
ing ignition coil.
6. Defective CDI unit.
7. Defective stator coil.
8. Low float chamber fuel level.
9. Dirty air cleaner element.
10. Clogged fuel hose, resulting in inadequate fuel supply
to the carburetor.
11. Clogged fuel valve vacuum pipe.
Replace.
Replace.
Replace.
Regap or replace.
Replace.
Replace.
Replace.
Adjust float height.
Clean.
Clean and prime.
Clean.
Dirty or heavy
exhaust smoke. 1. Incorrect engine oil. Change.
Engine lacks power. 1. Worn cylinder.
2. Worn piston rings.
3. Stiff piston rings.
4. Gas leaks from crankshaft oil seal.
5. Insufficient spark plug gap.
6. Clogged carburetor jet.
7. Incorrect float chamber fuel level.
8. Clogged air cleaner element.
9. Fouled spark plug.
10. Air leakage from intake pipe.
11. Slipping or worn drive belt.
12. Damaged or worn rollers in the movable drive face.
13. Weakened movable drive face spring.
14. Rich air-fuel mixture due to defective starter system.
Replace.
Replace.
Replace.
Replace.
Regap or replace.
Clean.
Adjust float height.
Clean.
Clean or replace.
Tighten or replace.
Replace.
Replace.
Replace.
Replace.
Engine overheats. 1. Carbon build-up on piston crown.
2. Defective oil pump or clogged oil circuit.
3. Low float chamber fuel level.
4. Air leakage from intake pipe.
5. Incorrect engine oil.
6. Incorrect spark plug.
7. Clogged exhaust pipe/muffler. Clean.
Clean or replace.
Adjust float height.
Tighten or replace.
Change.
Change.
Clean or replace.