Suzuki RM-Z250 - Engine

3-2 TROUBLESHOOTING
ENGINE
Complaint Symptom and possible causes Remedy
Engine will not start
or is hard to start.
Compression too low
• Valve clearance out of adjustment
• Worn valve guides or poor seating of valves
• Mistiming valves
• Excessively worn piston ring
• Worn-down cylinder bore
• Poor seating of spark plug
• Broken, cracked, or damaged piston
• Defective automatic decomp.
Plug not sparking
• Fouled spark plug
• Wet spark plug
• Incorrect spark plug gap
• Defective ignition coil/plug cap
• Defective CDI unit
• Open-circuited wiring connections
• Defective magneto
No fuel reaching the carburetor
• Clogged fuel tank vent hose
• Clogged or defective fuel valve
• Clogged fuel hose
• Defective carburetor float valve
Adjust
Repair or replace
Adjust
Replace
Replace
Retighten
Replace
Clean or replace
Replace
Clean and dry
Adjust
Replace
Replace
Repair or replace
Replace
Clean or replace
Clean or replace
Clean or replace
Clean or replace
Engine idles poorly. • Valve clearance out of adjustment
• Valve timing out of adjustment
• Poor seating of valves
• Worn valve guide
• Worn down camshafts
• Incorrect spark plug gap
• Defective ignition coil/plug cap
• Defective CDI unit
• Defective magneto
• Defective throttle position sensor
• Sucking air from intake pipe
• Insufficient throttle cable play
Adjust
Adjust
Repair or replace
Replace
Replace
Adjust
Replace
Replace
Replace
Adjust or replace
Retighten or replace
Adjust
Engine stalls often. • Dirty spark plug
• Defective ignition system
• Clogged fuel hose
• Valve clearance out of adjustment
Replace
Replace
Clean
Adjust