HYOSUNG RX 125 Service Manual page 153

Complaint
Noisy engine.
Slipping clutch.
Dragging clutch.
Transmission will
not shift.
Transmission will
not shift back.
Transmission
jumps out of gear.
Engine idles
poorly.
Engine runs
poorly in high
speed range.
Dirty or heavy
exhaust smoke.
Symptom and possible causes
Noise seems to come from transmission
1. Gears worn or rubbing.
2. Badly worn splines.
3. Primary gears worn or rubbing.
3. Badly worn bearings.
1. Clutch control out of adjustment or too much play.
2. Weakened clutch springs.
3. Worn or distorted pressure plate.
4. Distorted clutch plates, driven and drive.
1. Clutch control out of adjustment or too much play.
2. Weakened clutch springs.
3. Distorted clutch plates, driven and drive.
1. Broken gearshift cam.
2. Distorted gearshift forks.
3. Worn gearshift pawl.
1. Broken return spring on shift shaft.
2. Shift shafts are rubbing or sticky.
3. Distorted or worn gearshift forks.
1. Worn shifting gears on driveshaft or countershaft.
2. Distorted or worn gearshift forks.
3. Weakened stopper pawl spring on gearshift cam.
4. Worn gearshift pawl.
1. Valve clearance out of adjustment.
2. Poor seating of valves.
3. Defective valve guides.
4. Worn rocker arm or arm shaft.
5. Spark plug gap too wide.
6. Defective ignition coil resulting in weak sparking.
7. Float-chamber fuel level out of adjustment in carburetor.
8. Clogged jets.
1. Valve springs weakened.
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.
1. Too much engine oil in the engine.
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.
SERVICING INFORMATION 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.
Adjust or replace.
Replace.
Adjust.
Clean.
Replace.
Adjust.
Replace.
Repair.
Replace.
Adjust .
Clean.
Clean or replace.
Check with inspection win-
dow, drain out excess oil.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.