2004-2006 Honda FourTrax Rancher TRX350TE/TM/FE/FM Service Manual, Page 144Get this manual
CYLINDER HEADVALVE HEAD COVER Clean the mating surfaces of the head cover and cylinder headBlow through the oil passage in the head cove with compressed airInstall the follow ing: new gasket new O-ring (coat with engine oilRING
Insta ll the cy linder head cover and tighten the four bo ltsInstal the heat guard and fuel tank (page 6-21)