Yamaha RS90GTZ Service Manual page 34

VALVE CLEARANCE ADJUSTMENT
2-11
5. Measure:
• Valve clearance
Out of specification → Adjust.
Valve clearance (cold):
Intake valve:
0.15 ~ 0.22 mm
(0.0059 ~ 0.0087 in)
Exhaust valve:
0.21 ~ 0.25 mm
(0.0083 ~ 0.0098 in)
Checking steps:
• Turn the crankshaft clockwise.
• When piston #3 is at TDC on the compres-
sion stroke, align the TDC mark
magneto rotor with the mark
magneto cover.
TIP
TDC on the compression stroke can be found
when the camshaft lobes are turned away from
each other.
• Measure the valve clearance with a feeler
gauge set (thickness gauge)
Feeler gauge set:
YU-26900-9
Thickness gauge:
90890-03180
TIP
• If the valve clearance is incorrect, record the
measured reading.
• Measure the valve clearance in the following
sequence.
Valve clearance measuring sequence
Cylinder #3 → #2 → #1
INSP
ADJ
on the AC
on the AC
.