2007-2009 Honda TRX300EX TRX300X service manual, Page 128Get this manual
CYLINDER HEADNALVE REFACING Follow th refacing manufacturer's operating instructions
Valve seat cuttersgrinders or equivalent valve seat refacing equipment are recommended to correct worn valve seats
If the contact area is too high on the valve, the seat must be lowered using 32 flat cutterIf the contact area is too Iowan the valve, the seat must be ra ised using 60 interior cutter
Rerace the seat Use 45 seat cutter to remove any roughness or with 45 curter irregularities from the seatwhenever valve guide is replacedTOOLS: