Yamaha RS90GTZ Service Manual page 264

VALVES AND VALVE SPRINGS
11.Measure:
• Valve spring free length
Out of specification → Replace the valve
spring.
12.Measure:
• Compressed valve spring force
Out of specification → Replace the valve
spring.
Installed length
13.Measure:
• Valve spring tilt
Out of specification → Replace the valve
spring.
14.Inspect:
• Valve lifter
Damage/scratches → Replace the valve
lifters and cylinder head.
5-39
ENG
Valve spring free length (intake
and exhaust):
40.14 mm (1.58 in)
<Limit>: 38.14 mm (1.50 in)
Compressed valve spring force
(installed):
103.40 ~ 119.00 N at 34.60 mm
(10.54 ~ 12.13 kgf at 34.60 mm,
23.24 ~ 26.75 lbf at 1.36 in)
Maximum valve spring tilt:
2.5°/1.8 mm (2.5°/0.07 in)