1997-2001 Honda TRX250 Fourtrax Recon Service Manual, Page 114Get this manual
CYLINDER HEADCYLINDERPISTON Apply thin coaling of Prussian Blue to tile va lve seat, Press the valve through the valve guide and onto the seat to make clear pattern If the contact area is too high on the valve, the seat must be lowered using 32-degree flat cutter
The location of the valve seat in relation to the valve face is very Impor tant for good sealing
CONTACT TOO HIGH
If the contact area is too low on the valve, the seat must be ra ised using 60-degree inner cutter