Poor Performance At High Speed - Honda CRF450X 2005 Service Manual

TROUBLESHOOTING
POOR PERFORMANCE AT HIGH SPEED
22-6
1. Fuel line Inspection
Disconnect fuel line 8t carburetor.
Does fuel flow freely ?
NO _ . Clogged fuel line
• Clogged fu el tank breath er
• Fau lty fuel valve
• Clogged the fuel strainer screen
YES - GO TO STEP 2.
2. Carburetor Inspection
Check carburetor for clogs .
Is the carburetor clogged?
YES - Carburetor not serviced frequently enough.
NO - GO TO STEP 3.
3. Ignition Timing Inspection
Check ignition timing .
Is the ignition timing correct?
NO _ . Faulty ignition control module
oeM)
• Faulty ignition pulse generator
YES - GO TO STEP 4.
4. Valve Timing Inspection
Check valve timing.
Is the valve timing correct?
NO - Cam chain not installed properly.
YES - GO TO STEP 5.
5. Valve Spring Inspection
Check valve springs.
Are the vslve springs weak?
YES - Faulty \181\18 spring .
NO - Not weak.