Suzuki RM125 - Troubleshooting

3-2 TROUBLESHOOTING
TROUBLESHOOTING
ENGINE
Complaint Possible Cause Remedy
Engine does not start
or hard to start
Fuel deterioration
No fuel flow to the carburetor
• Fuel valve clogged
• Fuel hose clogged
• Fuel tank cap breather hose clogged
• Carburetor float valve malfunction
Too rich air/fuel mixture in combustion chamber
Incorrect ignition timing
No spark at spark plug
Low compression
• Piston ring worn or stuck
• Cylinder worn
• Air leak from cylinder gasket
• Air leak from crankshaft oil seal
Replace
Clean
Clean or replace
Clean
Replace
Scavange
Adjust
13-6
Replace
Replace
Replace
Replace
Engine stalls Fuel deterioration
Fouled spark plug
Fuel hose clogged
Air cleaner clogged
Carburetor jets clogged
Low compression
• Piston ring worn or stuck
• Cylinder worn
• Air leak from cylinder gasket
• Air leak from crankshaft oil seal
Incorrect ignition timing
Replace
Clean or replace
Clean or replace
Clean or replace
Clean
Replace
Replace
Replace
Replace
Adjust
Insufficient power Fuel deterioration
Brake dragging
Exhaust pipe cracked or clogged with carbon
Exhaust valve maladjustment
Exhaust valve carbon deposits
Air cleaner element clogged
Carburetor jets clogged
Incorrect fuel level in carburetor
Incorrect spark plug gap
Cylinder or piston ring worn
Reed valve malfunction
Incorrect ignition timing
Replace
Adjust
Replace or clean
Adjust
Clean
Clean or replace
Clean or replace
Adjust
Adjust or replace
Replace
Replace
Adjust