2004-2009 Honda TRX450R/TRX450ER Service Manual, Page 157Get this manual
FUEL SYSTEM (After '05) Set the return spring to the throttle drum assemblyRETURN SPRING
::::;OTTLEDRUM ASSEMBLY
Set the thrust washer, nylon washer and throttle shift armAlign the flat side of Insert the throttle shaft through the thrust washer, the throttle shaft tip nylon washer and throttle shift armwith the throttle Turn the throttle drum and check for smooth operaposition sensor tiontabs