2004-2009 Honda TRX450R/TRX450ER Service Manual, Page 125Get this manual
FUEL SYSTEM ('04-'05) Remove the two screws and the link arm with the spring from the throttle valveLINK ARM THROTTLE VALVE
Remove the jet needle from the throttle valveCheck the jet needle for stepped wear or damageCheck the throttle valve for scoring, scratches or damage
THROTTLE VALVE