2001-2006 Honda TRX 300EX Sportrax 300EX Factory Service Manual, Page 127Get this manual
CYLINDER HEADVALVES Check thaI the O-rings are in good condi tion, and replece them if necessaryInstall the valve adjuster covers and tight en the bolts
Connect the cran kcase breather tube to the eylinder head cover
BREATHER
Insall rh6 ou-slde sealing washer
groove aligning
the Iockmg lab on