Valve Seat Inspection/Refacing - Honda Transalp XL700V Manual

CYLINDER HEAD/VALVES

VALVE SEAT INSPECTION/REFACING

INSPECTION
Clean all intake and exhaust valves thoroughly to
remove carbon deposits.
Apply a thin coat of Prussian Blue to each valve
face.
Tap the valve against the valve seat several times
using a hand-lapping tool, without rotating valve, to
make a clear pattern.
Remove the valve and inspect the valve seat face.
• The valve cannot be ground. If the valve face is
burned or badly worn or if it contacts the seat
unevenly, replace the valve.
Inspect the valve seat face for:
• Uneven seat width:
– Replace the valve and reface the valve seat.
• Damaged face:
– Replace the valve and reface the valve seat.
• Contact area (too high or too low area):
– Reface the valve seat.
Inspect the width of the valve seat.
The valve seat contact should be within the speci-
fied width and even all around the circumference.
STANDARD:
SERVICE LIMIT: 1.5 mm (0.06 in)
If the valve seat width is not within specification,
reface the valve seat.
8-20
0.90 – 1.10 mm (0.035 – 0.043 in)
LAPPING TOOL
DAMAGED FACE
TOO LOW
UNEVEN SEAT
WIDTH
TOO HIGH
VALVE SEAT
CONTACT WIDTH