Valve Seat Inspection And Refacing; Seat Width - Honda CH250 Elite 1986 Service Manual

CYLINDER HEAD/VALVES
NOTE
• After the in, check the for dall1age,
Cvlinljer head heat should still be at 100°C (212°FI for in-
stallation of the new
the valve driver so that the valve is 12
mm (0.47 in),
Drive a new guides into the cylinder head from the rocker arm
side,
Let the head cool to room temperature and ream the
new valve guides,
NOTE
• Use oil on the reamer this operation.
• Rotate the reamer in the same direction when inserting and
removing it,
Reface the valve seat and clean the cylinder head thoroughly
to remove any metal particles.
VALVE SEAT INSPECTION AND REFACING
Clean all intake and exhaust valves thoroughly to remove
carbon deposits.
a
coating of valve compound to each valve
face. Lap each valve and seat using
a
rubber hose or other
hanCl-ialDplno tool.
NOTE
Do not allow the to enter between the valve
stem and After lapping, wash out the compound
cOlmp,letely and apply a coat of oil to the valve face
and set.
Remove the valve and inspect the face,
CAUTION
• The valves cannot be If the '-"~.I
_,.,
is burned, worn
unevenly, or
if
it
contacts the seat the valve must
be
the valve seat.
If the seat is too wide, too narrow, or has low spots, the seat
must be ground.
SEAT WIDTH:
Service limit: 1.8 mm 10,07 in)
(1) VALVE GUIDE REAMER
07984- MA60000
*=@~~~~~~~
(1)
SEAT WIDTH
6-9