1986-1987 Honda TRX350 FourTrax 4X4, 1987-1989 TRX350D Foreman 4X4 Service Manual, Page 79Get this manual
CYLINDER HEADIV AL VES Apply thin coating of Prussian Blue to the valve seatInsert the valve through the valve guide until it seats to make clear pattern NOTE The location of the valve seat in relation to the valve face is very important for good sealingIf the contact area is too high on the valve, the seat must be lowered using 32 degree flat cutter
(1) CONTACT TOO HIGH
(2) OLD SEAT WIDTH
If the contact area is too low on the valve, the seat must be raised using 60 degree inner cutter
(1CONTACT TOO LOW
(21 OLD SEAT WIDTH
Refinish the seat to specifications, us ing 45 degree finish cutterAfter cutting the seat, apply lapping compound to the valve face, and lap the valve using hand lapping toolAfter lapping, wash all residual compound off the cylinder head and valveNOTE Do not allow lapping compound to enter the guides