Yamaha RS90K Manuel D'atelier page 737

Model
Valve spring:
Free length
Intake
<Limit>
Exhaust
<Limit>
Installed length (valve closed)
Intake
Exhaust
Compressed spring force (installed)
Intake
Exhaust
Spring tilt
Intake
Exhaust
Winding direction (top view)
Intake
Exhaust
Valve lifter:
Valve lifter outside diameter
Intake
<Limit>
Exhaust
<Limit>
Valve lifter hole inside diameter
Intake
<Limit>
Exhaust
<Limit>
Piston:
Piston size (D)
Measuring point (H)
Piston to-cylinder clearance
<Limit>
Piston pin bore off set
Off-set direction
Piston pin bore inside diameter
Piston pin:
Piston pin outside diameter
Piston pin length
Piston pin to piston pin bore clearance
<Limit>
MAINTENANCE SPECIFICATIONS
RS90/RS90R/RSG90/RS90M/RST90/RST90TF
39.73 mm (1.56 in)
37.7 mm (1.48 in)
39.73 mm (1.56 in)
37.7 mm (1.48 in)
33.0 mm (1.30 in)
33.0 mm (1.30 in)
136 ~ 158 N (13.9 ~ 16.1 kg, 30.6 ~ 35.5 lb)
136 ~ 158 N (13.9 ~ 16.1 kg, 30.6 ~ 35.5 lb)
2.5°/1.7 mm (0.07 in)
2.5°/1.7 mm (0.07 in)
Clockwise
Clockwise
24.482 ~ 24.488 mm (0.9639 ~ 0.9641 in)
24.457 mm (0.9629 in)
24.482 ~ 24.488 mm (0.9639 ~ 0.9641 in)
24.457 mm (0.9629 in)
23.15 ~ 23.30 mm (0.9114 ~ 0.9173 in)
23.33 mm (0.9185 in)
23.15 ~ 23.30 mm (0.9114 ~ 0.9173 in)
23.33 mm (0.9185 in)
78.935 ~ 78.950 mm (3.1077 ~ 3.1083 in)
5.0 mm (0.20 in)
H
0.050 ~ 0.075 mm (0.0020 ~ 0.0030 in)
D
0.120 mm (0.0047 in)
0.5 mm (0.0197 in)
Exhaust side
19.004 ~ 19.015 mm (0.7482 ~ 0.7486 in)
18.991 ~ 19.000 mm (0.7477 ~ 0.7480 in)
52.9 ~ 53.0 mm (2.0827 ~ 2.0866 in)
0.004 ~ 0.024 mm (0.0002 ~ 0.0009 in)
0.074 mm (0.0029 in)
9-6
SPEC