2004-2009 Honda TRX450R/TRX450ER Service Manual, Page 226Get this manual
CYLINDER HEADVALVE
CYLINDER HEAD COVER INSTALLATION
Clean the mating surfaces of the cylinder head and cover thoroughly, being careful not to damage themApply adhesive to the gasket groove in the cylinder head cover and install new gasketInstall new rubber seal into spark plug holeInstall the head cover by aligning the plug hole with the plug sleeve, being careful not to damage the rubber sealHEAD COVER