1999-2004 Honda TRX400EX FourTrax Service Manual, Page 99Get this manual
CYLINDER HEADVALVE REFACING NOTE:
Follow the refacing manufacturer's operating instructionsBe careful not to grind the seat more than necessary
If the contact area is too high on the valve, the seat must be lowered using 32" flat cutterIf the contact area is too low on the valve, the seat must be raised using 60" interior cutter
CONTACT TOO HIGH
CONTACT TOO LOW
OLD SEAT WIDTH
Using 45" seat cutter, remove any roughness or irregularities from the seat
OLD SEAT WIDTH