Valve Seats Inspection; Valve Guide Reaming - Honda Motorcycle Service Manual

CYLINDER HEAD
While the cylinder head is still heated, drive a new valve guide
in from valve spring side until the exposed height is the same
as was measured for the old guide.
Let the cylinder head cool to room temperature and ream the
new valve guide.
VALVE GUIDE REAMING
When reaming new valve guides, insert the valve guide reamer
from the combustion chamber side.
NOTE
.
Take care not t o tilt or lean the reamer in the guide
while reaming
.
If reaming is irreguler, oil will leak past the valve stem
seal. It could cause improper seat contact that cannot be
corrected by refacing.
Use cutting oil on the reamer during this operation.
Rotate the reamer clockwise, never counterclockwise
when inserting and removing
Reface the valve seats and clean the cylinder head thoroughly
to remove any metal particles.
VALVE SEATS
INSPECTION
Clean all intake and exhaust valves thoroughly to remove car-
bon deposits.
Apply a light coating of Prussian Blue to each valve face.
Tap the valve against the valve seat several times with your
finger, without rotating the valve, t o check for proper valve
seat contact.
Remove the valve and inspect the valve seat face.
The valve seat contact should be within the specified width and
even all around the circumference. (Refer to the model
VALVE GUIDE
REMOVER or
I
1 5
VALVE GUIDE REAMER
VALVE
I/
specific manual for the seat width.)
If the valve seat width is not within specification, reface
the valve seat (page 9-1 2).
NOTE
-
Most valve faces and stem tips are coated with a thin
layer of stellite so they cannot be ground. If a valve face
or stem tip is rough, worn unevenly, or contacts the seat
improperly, the valve must be replaced.
Date of Issue: March. 1995
O
HONDA MOTOR CO.,LTD.
9-1
5