1997-2004 Honda Fourtrax Recon TRX250TE/TM Service Manual, Page 124Get this manual
CYLINDER HEADCYLINDERPISTON Remove and inspect the valvesCAUTION :
The valves cannot be groundIf valve 'ace is burned or badly worn or if it contacts the seat
unevenly, replace the valve
Inspect the width of each valve seatSTANDARD: 1.2 mm (0.05 inl SERVICE LIMIT: 1.5 mm (0.06 in)
If the seat is too wide, too narrow or has low spots, the seat must be ground
VALVE SEAT REFACING
Follow the refaeer manufacturer's operating instruction
Reface the valve seat whenever the valve guide