Yamaha YFZ450S 2003 Service Manual page 82

ADJUSTING THE VALVE CLEARANCE
6. Adjust:
• valve clearance
M MMM M MMM M M MMM
a. Remove the valve lifter 1 and the valve pad
2 with a valve lapper 3.
Valve lapper
90890-04101
NOTE:
_
• Cover the timing chain opening with a rag to
prevent the valve pad from falling into the
crankcase.
• Make a note of the position of each valve
lifter 1 and valve pad 2 so that they can be
installed in the correct place.
b. Select the proper valve pad from the follow-
ing table.
Valve pad thickness
range
Nos. (0.047) ~
120 ~ 240 2.40 mm
(0.094 in)
NOTE:
_
• The thickness a of each valve pad is
marked in hundredths of millimeters on the
side that touches the valve lifter.
• Since valve pads of various sizes are origi-
nally installed, the valve pad number must be
rounded in order to reach the closest equiva-
lent to the original.
c. Round off the original valve pad number
according to the following table.
Last digit
0 or 2
5
8
3 - 10
CHK
ADJ
M M MMM M M MMM M
Available valve pads
1.20
25 thicknesses in
0.05 mm (0.002 in)
increments
Rounded value
0
5
10
M MMM M MMM