7-1 SERVICING INFORMATION
TROUBLESHOOTING
ENGINE
Complaint
Symptom and possible causes
Remedy
Engine will not
start, or is hard
to start.
Compression too low
1. Valve clearance out of adjustment.
2. Worn valve guides or poor seating of valves.
3. Valves mistiming
4. Piston rings excessively worn.
5. Worn-down cylinder bore.
6. Poor seating of spark plug.
7. Starter motor cranks but too slowly.
Plug not sparking
1. Fouled spark plug.
2. Wet spark plug.
3. Defective ignition coil.
4. Open or short circuit in high tension cord.
No fuel reaching the carburetor
1. Clogged hole in the fuel tank cap.
2. Clogged or defective fuel cock.
3. Defective carburetor float valve.
4. Clogged fuel pipe.
Adjust.
Repair or replace.
Adjust.
Replace.
Replace or rebore.
Retighten.
Consult
“electrical complaints”
Clean or replace.
Clean and dry.
Replace.
Replace..
Clean.
Clean or replace.
Replace.
Clean or replace.
Noisy engine.
Excessive valve chatter
1. Valve clearance too large.
2. Weakened or broken valve springs.
3. Worn down rocker arm or rocker arm shaft.
Noise appears to come from piston
1. Piston or cylinder worn down.
2. Weakened or broken valve springs.
3. Worn down rocker arm or rocker arm shaft.
4. Piston rings or ring groove worn.
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 cluth plates.
3. Distorted clutch plates, driven and drive.
Noise seems to come from crankshaft
1. Worn or broken bearings.
2. Big-end bearings worn and broken.
3. Thrust clearance too large.
Adjust.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Repair or replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Engine stalls
easily.
1. Fouled spark plug.
2. Clogged fuel hose.
3. Clogged jets in carburetor.
4. Valve clearance out of adjustment.
Clean.
Clean.
Clean.
Adjust.
Summary of Contents for RX 125 -
Page 1: ...SERVICE MANUAL 99000 97100 SERVICE MANUAL HYOSUNG MOTORS MACHINERY INC RX125 RX 125 ...
Page 5: ......
Page 29: ...PERIODIC MAINTENANCE 2 16 ...
Page 94: ...FUEL SYSTEM 4 12 Start motor Piston Cylinder Oil cooler Cylinder head Crankcase Transmission ...
Page 118: ...CHASSIS 6 6 FRONT BRAKE yyy yyy yyy yyy yy yy y y ...
Page 126: ...CHASSIS 6 14 FRONT FORK ...
Page 132: ...CHASSIS 6 20 STEERING STEM ...
Page 143: ...6 31 CHASSIS SUSPENSION Service limit 10 20 mm Service limit 14 20 mm Service limit 10 20 mm ...
Page 150: ...CHASSIS 6 38 SPACER Apply grease to the spacer when installing Super grease A ...