Valve Seat Inspection/Refacing - Honda TRX680FA Service Manual

CYLINDER HEAD/VALVE/CAMSHAFT
Take care not to tilt
or lean the reamer
in the guide while
reaming.
Use cutting oil on
the reamer during
this operation.
Ream the new valve guides.
Insert the reamer from the combustion chamber
side of the head and always rotate the reamer clock-
wise.
REAMER
TOOL:
Valve guide reamer, 5.5 mm 07984-2000001 or
07984-200000D
(U.S.A. only)
Clean the cylinder head thoroughly to remove any
metal particles after reaming and reface the valve
seat (page 9-14).
VALVE SEAT INSPECTION/REFACING
INSPECTION
Clean all intake and exhaust valves thoroughly to
remove carbon deposits.
Apply a light coat of Prussian Blue to each valve
seat.
Tap the valve against the valve seat several times
without rotating the valve, to check for proper valve
seat contact.
The valve cannot be
ground. If the valve
face is burned or
badly worn or if it
contacts the seat
unevenly, replace
the valve.
Remove the valve and inspect the valve seat face.
The valve seat contact should be within the speci-
fied width and even all around the circumference.
STANDARD: 1.0 - 1.1 mm (0.039 - 0.043 in)
SERVICE LIMIT: 1.4 mm (0.06 in)
If the valve seat width is not within specification,
reface the valve seat.
¥
mmmmawK
' I SEAT WIDTH
Inspect the valve face for:
• Damaged face:
- Replace the valve and reface the valve seat.
• Uneven seat width:
- Replace the valve and reface the valve seat.
DAMAGED FACE
UNEVEN SEAT WIDTH
9-13