2006-2009 Honda TRX250EX/TRX250X Service Manual, Page 140Get this manual
CYLINDER HEADIVALVECAMSHAFT
CYLINDER HEAD INSTALLATION
Be careful not to damage the marmg surfaces
Clean the mating surfaces of the cylinder head and cylinder thoroughlyBlowout the oil passage in the cylinder head wi th compressed airInstall the dowel pins and new gasket
Install the cylinder head onto the cylinderApply engine oil to the threads and seating surfaces of the cylinder head nuts and install them with the washers