2005-2008 Honda ATV TRX500FA/FGA Fourtrax, Rubicon Factory Service Manual, Page 536Get this manual
TROUBLESHOOTING
POOR PERFORMANCE AT HIGH SPEED
1Fuel Line Inspection Disconnect fuel line at carburetorDoes fuel flow freely? NO YES Clogged fuel line Clogged fuel tank breather hose Faulty fuel valve Clogged fuel strainer
GO TO STEP 2
2Carburetor Inspection Check carburetor for cloggingIs the carburetor clogged? YES NO Carburetor not serviced frequently enough GO TO STEP 3
3Valve Timing Inspection Check valve timingIs the valve timing correct? NO YES Camshaft not installed properly GO TO STEP 4