Yamaha TT-R90(S) Owner's Service Manual page 144

VALVE CLEARANCE ADJUSTMENT
1
3 2
1
4. Check:
Valve clearance
G
Out of specification → Adjust.
Valve clearance (cold):
Intake valve:
0.05 ~ 0.09 mm
(0.0020 ~ 0.0035 in)
Exhaust valve:
0.08 ~ 0.12 mm
(0.031 ~ 0.047 in)
Checking steps:
Turn the crankshaft counterclockwise with
G
a wrench.
Align the T.D.C. mark a on the rotor with
G
the align mark b on the crankcase cover
when piston is at T.D.C. on compression
stroke.
Measure the valve clearance using a
G
feeler gauge 1.
Out of specification → Adjust clearance.
5. Adjust:
Valve clearance
G
Adjustment steps:
Loosen the locknut 1.
G
Turn the adjuster 3 in or out with the
G
valve adjusting tool 2 until specified clear-
ance is obtained.
Turning in →
Valve clearance is decreased.
Turning out →
Valve clearance is increased.
Valve adjusting tool:
YM-8035/90890-01311
Hold the adjuster to prevent it from moving
G
and tighten the locknut.
Measure the valve clearance.
G
If the clearance is incorrect, repeat above
G
steps until specified clearance is obtained.
3 - 9
INSP
ADJ
7 Nm (0.7 m · kg, 5.1 ft · lb)