Adjusting The Valve Clearance - Yamaha YJ125S Service Manual

ADJUSTING THE VALVE CLEARANCE

2
1
2
b
1
a
3
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a. Turn the crankshaft counterclockwise.
b. When the piston is at TDC on the compres-
sion stroke, align the punch mark in the
camshaft sprocket with the stationary on the
cylinder head.
c. Align the TDC mark 1 on the magneto ro-
tor with the stationary pointer 2 on the
crankcase.
d. Measure the valve clearance with a thick-
ness gauge.
Out of specification
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4. Adjust:
8 valve clearance
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a. Loosen the locknut 1.
b. Insert a thickness gauge 2 between the
end of the adjusting screw and the valve
tip.
c. Turn the adjusting screw 3 in direction a
or b until the specified valve clearance is
obtained.
Direction a
Valve clearance is increased.
Direction b
Valve clearance is decreased.
Tappet adjusting tool
90890-01311 (YM-08035-A)
d. Hold the adjusting screw to prevent it from
moving and tighten the locknut to specifi-
cation.
8 locknut
7 Nm (0.7 m • kg, 5.1 ft • lb)
e. Measure the valve clearance again.
f. If the valve clearance is still out of specifi-
cation, repeat all of the valve clearance ad-
justment steps until the specified clearance
is obtained.
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3-8
CHK
ADJ
Adjust.