Valve Stem - HYOSUNG GF125 Service Manual

Complaint
Noisy engine.
Noise seems to come from transmission
1. Gears worn or rubbing.
2. Badly worn splines.
3. Primary gears worn or rubbing.
4. Badly worn bearings.
1. Clutch contorl out of adjustment or loss of play.
Slipping clutch.
2. Weakened clutch springs.
3. Worn or distorted pressure plate.
4. Distored clutch plates, driven and drive.
Dragging clutch. 1. Clutch control out of adjustment or too much play.
2. Some clutch spring weakened while others are not.
3. Distorted pressure plate or clutch plates.
Transmission will 1. Broken gearshift cam.
not shift.
2. Distorted gearshift forks.
3. Worn gearshift pawl.
1. Broken return spring on shift shaft.
Transmission will
not shift back.
2. Shift shafts are rubbing or sticky.
3. Distorted or worn gearshift forks.
Transmission jumps
1. Worn shifting gears on driveshaft or countershaft.
out of gear.
2. Distorted or worn gearshift forks.
3. Weakened stopper pawl spring on gearshift cam.
4. Worn gearshift pawl.
1. Valve clearance out of adjustment.
Engine idles
poorly.
2. Poor seating of valves.
3. Defective valve guides.
4. Worn rocker arm or arm shaft.
5. Defective pick up coil.
6. Defective C.D.I unit.
7. Spark plug gap too wide.
8. Defective ignition coil resulting in weak sparking.
9. Float-chamber fuel level out of adjustment in Carburetor.
10. Clogged jets.
1. Valve springs weakend.
Engine runs poorly
in speed range.
2. Valve timing out of adjustment.
3. Worn cams or rocker arms.
4. Spark plug gap too narrow.
5. Defective ignition coil.
6. Float-chamber fuel level too low.
7. Clogged air cleaner element.
8. Clogged fuel pipe, resulting in inadequate fuel supply to carburetor.
9. Defective pick up coil or C.D.I unit.
1. Too much engine oil in the engine.
Dirty or heavy
exhaust smoke.
2. Worn piston rings or cylinder.
3. Worn valve guides.
4. Cylinder wall scored or scuffed.
5. Worn valves stems.
6. Defective stem seals.
7. Worn side rails.
Symptom and possible causes
SERVICING INFORMA TION 7-2
Remedy
Replace.
Replace.
Replace.
Replace.
Adjust.
Replace.
Replace.
Replace.
Adjust
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Repair
Replace.
Replace.
Replace.
Replace.
Replace.
Adjust.
Replace.
Replace.
Replace.
Replace.
Replace.
Adjust or replace.
Replace.
Adjust.
Clean.
Replace.
Adjust
Replace.
Repair.
Replace.
Adjust.
Clean.
Clean and prime.
Replace.
Check with insection window, drain out excess
oil.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.