2007-2009 Honda TRX300EX TRX300X service manual, Page 354Get this manual
TROUBLESHOOTING
POOR PERFORMANCE AT HIGH SPEED
1Fuel Line Inspection
Disconnect fuel line at carburetorDoes fuel flow freely?
- Clogged fuel line
Clogged fuel fill cap breather Faulty fuel valve Clogged fuel strainer
- GO TO STEP 2
2Carburetor Inspection
Check carburetor for cloggingIs the carburetor clogged? YESCa rburetor not serviced frequently enough
- GO TO STEP 3
3Valve Timing Inspection
Check valve timingIs the valve timing correct?
- Camshaft not installed properly
- GO TO STEP 4