Yamaha YFM25RY Automobile User Manual


 
VALVES AND VALVE SPRINGS
5-21
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EAS24310
CHECKING THE VALVE SPRINGS
The following procedure applies to all of the
valve springs.
1. Measure:
Valve spring free length “a”
Out of specification Replace the valve
spring.
2. Measure:
Compressed valve spring force “a”
Out of specification Replace the valve
spring.
3. Measure:
Valve spring tilt “a”
Out of specification Replace the valve
spring.
Inner spring
Free length (intake)
36.17 mm (1.42 in)
Free length (exhaust)
36.17 mm (1.42 in)
Outer spring
Free length (intake)
36.63 mm (1.44 in)
Free length (exhaust)
36.63 mm (1.44 in)
a. Compressed valve spring force
b. Installed length
Inner spring
Installed compression spring
force (intake)
75.00–91.70 N (7.65–9.35 kgf,
16.86–20.61 lbf)
Installed compression spring
force (exhaust)
75.00–91.70 N (7.65–9.35 kgf,
16.86–20.61 lbf)
Installed length (intake)
30.50 mm (1.20 in)
Installed length (exhaust)
30.50 mm (1.20 in)
Outer spring
Installed compression spring
force (intake)
128.50–157.90 N (13.10–16.10
kgf, 28.89–35.50 lbf)
Installed compression spring
force (exhaust)
128.50–157.90 N (13.10–16.10
kgf, 28.89–35.50 lbf)
Installed length (intake)
32.00 mm (1.26 in)
Installed length (exhaust)
32.00 mm (1.26 in)