2006 Honda TRX680 Rincon Factory Service Manual, Page 215Get this manual
CYLINDER HEADVALVECAMSHAFT Take care not to tilt or lean the reamer in the guide while reamingUse cutting oil on the reamer during this operation
Ream the new valve guidesInsert the reamer from the combustion chamber side of the head and always rotate the reamer clockwiseTOOL: Valve guide reamer, 5.5 mm 07984-2000001 or 07984-200000D (U.S.Aonly)
Clean the cylinder head thoroughly to remove any metal particles after reaming and reface the valve seat (page 9-14)
VALVE SEAT INSPECTIONREFACING
INSPECTION
Clean all intake and exhaust valves thoroughly to remove carbon depositsApply light coat of Prussian Blue to each valve seatTap the valve against the valve seat several times without rotating the valve, to check for proper valve seat contact