Polaris TRAIL BOSS 325 2001 Manual page 84

ENGINE
VALVE SEAT RECONDITIONING, CONT.
7. Remove valve and check where the Prussian Blue¥
or black marker indicates seat contact on the valve
face. The valve seat should contact the middle of the
valve face or slightly above, and must be the proper
width (A).
SIf the indicated seat contact is at the top edge of the
valve face and contacts the margin area(B) it is
too high on the valve face. Use the 30q cutter to
lower the valve seat.
SIf too low use the 60q or 75q cutter to raise the seat.
When contact area is centered on the valve face,
measure seat width.
SIf the seat is too wide or uneven, use both top and bot-
tom cutters to narrow the seat.
SIf the seat is too narrow, widen using the 45q cutter
and re-check contact point on the valve face and
seat width after each cut.
NOTE:When using an interference angle, the
seat contact point on the valve will be very narrow,
and is a normal condition. Look for an even and
continuous contact point on the black marker, all
the way around the valve face.
Valve Seat Width:
Intake Std: .039I (1.0 mm)
Limit: .055I (1.4 mm)
Exhaust Std: .059I (1.4 mm)
Limit: .071I (1.8 mm)
8. Clean all filings from the area with hot soapy water,
rinse, and dry with compressed air.
9. Lubricate the valve guides with clean engine oil, and
apply oil or water based lapping compound to the face
of the valve. Lapping is not required with an
interference angle.
3.28
Proper Seat Contact On Valve Face
Bottom - 60q or 75q
Seat - 45q or 46q
(B)
(A)
Seat
Width
Top - 30q