2004-2009 Honda TRX450R/TRX450ER Service Manual, Page 515Get this manual
TROUBLESHOOTING
ENGINE DOES NOT START OR IS HARD TO START
1Fuel Line Inspection Check the fuel flow to the carburetorDoes the fuel reach the carburetor? YES NOGO TO STEP 4('04'05) GO TO STEP 2(After '05)Clogged fuel line or strainer Clogged fuel valve Clogged fuel fill cap breather hose 2Throttle Cable Conditon Inspection (After '05 only) Oprerate the throttle leverDo the throttle lever and throttle drum operate smoothly? YES NoGO TO STEP 3- Improper throttle lever free play adjustment Stuck throttle cable 3Closed Throttle Position Detection System Inspection (After '05 only) Check the throttle lever and carburetor switchesAre the throttle lever andor carburetor switches correct? Yes NoGO TO STEP 4- Faulty throttle lever switch Faulty carburetor switch 4Spark Plug Inspection Remove and inspect the spark plugIs the spark plug wet? YESFlooded carburetor Throttle valve open Dirty air cleaner Improperly adjusted pilot screw