Valve Seat Inspection/Refacing Inspection - Honda 2003 NPS50 Ruckus Service Manual

CYLINDER HEAD/VALVES
Drive the new guides into the cylinder head from
the camshaft side while the cylinder head is still
heated.
TOOL:
Valve guide driver, 4.5 mm
VALVE GUIDE PROJECTION:
IN/EX: 9.05 - 9.35 mm (0.356 - 0.368 in)
Let the cylinder head cool to room temperature.
Ream the new valve guides after installation.
T ake care not to tilt Insert the reamer from the combustion chamber
or lean the reamer side of the head and also always rotate the reamer
in the guide while clockwise.
reaming.
TOOL:
Use cutting oil on
Valve guide reamer, 4.508 mm 07HMH-ML00101 or
the reamer during
this operation.
Clean the cylinder head thoroughly to remove any
metal particles after reaming and reface the valve
seat as described below.
VALVE SEAT INSPECTION/REFACING
INSPECTION
Clean the intake and exhaust valves thoroughly to
remove carbon deposits.
Apply a light coating of Prussian Blue to the valve
seats.
Tap the valve against the valve seat several times
using a hand-lapping tool, without rotating the
valve, to make a clear pattern.
Remove the valve and inspect the valve seat face.
The valves cannot
The valve seat contact should be within the speci­
be ground. ff the
fied width and even all around the circumference.
valve face is burned
or badly worn or if it
ST ANDARD:
contacts the seat
SERVICE LIMIT: 1.5 mm (0.06 in)
unevenly. replace
the valve.
If the valve seat width is not within specification,
reface the valve seat (page 9-14).
9-14
07HMD-ML00101
07HMH-ML0010B o r
07HMH-ML0010A
(U.S.A. only)
1.0 mm (0.04 in)
REAMER
SEAT WIDTH