Yamaha GRIZZLY Ultramatic YFM660FP, Service Manual

Page: 173 / 408

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ENG
VALVES AND VALVE SPRINGS
11.Measure:
●
Compressed spring force
a
Out of specification
→
Replace.
b
Installed length
Compressed spring force:
Intake:
100.0 ~ 115.7 N at 27.5 mm
(10.20 ~ 11.80 kg,
22.48 ~ 26.01 lb at 1.08 in)
Exhaust:
120.6 ~ 138.3 N at 31.0 mm
(12.30 ~ 14.10 kg,
27.11 ~ 31.09 lb at 1.22 in)
12.Measure:
●
Spring tilt
a
Out of specification
→
Replace.
Spring tilt limit:
Intake:
2.5°/1.4 mm (0.06 in)
Exhaust:
2.5°/1.6 mm (0.06 in)
INSTALLING THE VALVE AND VALVE
SPRING
1.Apply:
●
Molybdenum disulfide oil
(onto the valve stem and valve stem seal)
2.Install:
●
Valve spring seats
●
Valve stem seals
●
Valves
●
Valve springs
●
Valve spring retainers
NOTE:
Install the valve springs with the larger pitch
a
facing upwards.
b
Smaller pitch
New