Valve Seat Inspection/Refacing; Seat Width - Honda PCX150 2013 Service Manual

CYLINDER HEADNAlVES
The valves cannot
be ground. If the
valve face is
burned, badly worn
or if it contacts the
seat unevenly,
replace the valve.
10-18
VALVE SEAT INSPECTION/REFACING
INSPECTION
Disassemble the cylinder head (page 10-14 ).
Clean the intake and exhaust valves thoroughly to
remove carbon deposits.
Apply a light coat 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 valve seat contact should be within the specified
width and even all around the circumference.
STANDARD: 0.90-1.10 mm (0.035- 0.043 in)
SERVICE LIMIT: 1.5 mm (0.06 in)
If the valve seat width is not within specification, reface
the valve seat.
Inspect the valve seat face for:
• Damaged face:
- Replace the valve and reface the valve seat
• Uneven seat width:
- Bent or collapsed valve stem; Replace the valve
and reface the valve seat
Contact area too low or too high:
- Reface the valve seat
SEAT WIDTH
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