Yamaha YZ250F(D), Owner'S Service Manual

Page: 62 / 198

3-12
ENGINE
c. Select the proper pad using the
pad selecting table.
The thickness "a" of each pad is indi-
cated in hundredths of millimeters on
the pad upper surface.
d. Round off the last digit of the in-
stalled pad number to the nearest
increment.
EXAMPLE:
Installed pad number = 148
Rounded off value = 150
Pads can only be selected in 0.05
mm increments.
e. Locate the rounded-off value and
the measured valve clearance in
the chart "PAD SELECTION TA-
BLE". The field where these two
coordinates intersect shows the
new pad number to use.
Use the new pad number only as a
guide when verifying the valve clear-
ance adjustment.
f. Install the new pads "3" and the
valve lifters "4".
• Apply the engine oil on the valve lift-
ers.
• Apply the molybdenum disulfide oil
on the valve stem ends.
• Valve lifter must turn smoothly
when rotated with a finger.
• Be careful to reinstall valve lifters
and pads in their original place.
g. Install the camshafts (exhaust
and intake).
Refer to "CAMSHAFTS" section
in the CHAPTER 4.
Pad range
Pad Availabili-
ty: 25 incre-
ments
No.
120–
No.
240
1.20
mm–
2.40
mm
Pads are avail-
able in 0.05 mm
increments
Last digit of pad
number
Rounded valve
0, 1 or 2 0
4, 5 or 6 5
8 or 9 10