E
CAMSHAFT AND VALVES
POWR
Valve seat refacing
NOTE:
After refacing the valve seat or replacing
the valve and valve guide, lap the valve
seat and valve face.
c
C
8
To prevent chatter marks, turn the
valve seat cutter clockwise with an
even, downward pressure (4 ~ 5 kg).
8
Rotate the cylinder head to maintain
an even.
9
Refer to the following chart to deter-
mine the appropriate valve seat cut-
ter.
5-28
Valve seat cutter set:
YM-91043-C/90890-06803
Valve seat lapper:
N.A./90890-06805
A
B
C
Valve seat area
Valve cutter
A
90°
B
45°
C
30°
Valve seat cutting guidelines
1
The valve seat is centred on the valve face,
but is too wide.
Valve seat cutter set
Desired result
First:
Use
90° cutter
To reduce the
lightly
Second:
valve seat width.
30° cutter
1
