Yamaha TMAX 2020 Service Manual page 99

A
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A. Front
d. To measure the valve clearances of the
other cylinders, starting with cylinder #1 at
TDC, turn the crankshaft clockwise as
specified in the following table.
A
#1
B
#2
A. Degrees that the crankshaft is turned
clockwise
B. Cylinder
C. Combustion cycle
Cylinder #2
6. Remove:
• Camshaft
TIP
• Refer to "CAMSHAFTS" on page 5-12.
• When removing the timing chain and cam-
shafts, fasten the timing chain with a wire to re-
trieve it if it falls into the crankcase.
7. Adjust:
• Valve clearance
a. Remove the valve lifter and the valve pad
with a valve lapper.
Valve lapper (ø14)
90890-04101
Valve lapping tool (14mm)
YM-A8998
0˚ 360˚ 720˚
C
C
360
PERIODIC MAINTENANCE
TIP
• 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
and valve pad so that they can be installed in
the correct place.
b. Calculate the difference between the spec-
ified valve clearance and the measured
valve clearance.
Example:
Specified valve clearance = 0.15–0.22 mm
(0.0059–0.0087 in)
Measured valve clearance = 0.25 mm
(0.0098 in)
0.25 mm (0.0098 in) - 0.22 mm (0.0087 in)
= 0.03 mm (0.001 in)
c. Check the thickness of the current valve
pad.
TIP
The thickness "a" of each valve pad is marked in
hundredths of millimeters on the side that touch-
es the valve lifter.
Example:
If the valve pad is marked "155", the pad
thickness is 1.55 mm (0.061 in).
a
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d. Calculate the sum of the values obtained in
steps (b) and (c) to determine the required
valve pad thickness and the valve pad num-
ber.
Example:
1.55 mm (0.061 in) + 0.03 mm (0.001 in) =
1.58 mm (0.062 in)
The valve pad number is 158.
e. Round off the valve pad number according
to the following table, and then select the
suitable valve pad.
3-7