Honda TRX400EX FOURTRAX 1999, Service Manual

Page: 101 / 263

CYLINDER
Using a 60" interior cutter, remove of the existing
valve seat material.
TOOLS:
Interior cutter, 30 mm 07780-0014000
Cutter holder, 5.5
mm
07781 -0010101
or
equivalent commercially available in
Using a 45" seat cutter, cut the seat to the proper
width.
VALVE SEAT
WIDTH:
1.0
-
1.1 (0.039
-
0.043
Make sure that a l l pitting and irregularities are
removed.
OLD SEAT WIDTH
1.0 - 1.1 mm
(0.039
-
0.043 in)
After cutting the seat, apply lapping compound to the
valve face, and lap the valve using light pressure.
CAUTION
Excessive lapping pressure may deform or dam-
age the seat.
Change the angle of lapping t o o l frequently t o
prevent uneven seat wear.
Do n o t a l l o w lapping compound t o enter t h e
guides.
After lapping, wash any residual compound
off
the
cylinder head and valve and recheck the seat contact.
7-1