2004-2005 Honda TRX450R Factory Sevice Manual, Page 141Get this manual
CYLINDER HEADIVALVE Attach piece of -
cam sprocket (from the cam chain )
wireto the cam
chain to prevent it from falling into the crankcase
Shims may tick to the inside of the valve lif ters In the camsh aft holderDo not allow the shims to fall into the crankcase-
fo ur bolts (by loosening them in crisscross pattern in several stepscam shaft holder assembly