Note - Honda 2000 XR50R Service Manual

Use a 6O-degree cutter to remove the bottom 1/4 of
the old seat.
Remove the cutter and inspect the area you have
retaced.
Install a 45-degree finish cutter and cut the seat to
the proper width.
Make sure that all pitting and irregularities
BTe
re-
moved.
Refinish if necessary.
Apply
8
thin ,coati ng of Prussian Bl ue to the valve
seat.
Press the valve through the valve guide and onto
the seat to make a clear pattern.
NOTE :
The location of the valve seat in relation to the
valve face is very important for good sealing.
If the contact areB is too high on the valve, the seat
must be lowered using
8
32-degree flat cutter.
If the contact area is too low on the valve, the seat
must be raised using a 50-degree inner cutter.
Refinish the seat to specifications, using a 45·
degree finish cutter.
CYLINDER HEAD/VALVES
CONTACT TOO HIGH
-
CONTACT TOO LOW
OLD SEAT WIDTH
45·
OLD SEAT
WIDTH
7-11