Checking The Valve Springs - Yamaha WR250R Service Manual

h. Install the valve into the cylinder head.
i. Press the valve through the valve guide and
onto the valve seat to make a clear impres-
sion.
j. Measure the valve seat width "c" again. If the
valve seat width is out of specification, reface
and lap the valve seat.
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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"
G
Out of specification → Replace the valve
spring.
Valve spring free length
Free length (intake)
36.03 mm (1.42 in)
Limit
34.23 mm (1.35 in)
Free length (exhaust)
36.03 mm (1.42 in)
Limit
34.23 mm (1.35 in)
VALVES AND VALVE SPRINGS
2. Measure:
Compressed valve spring force "a"
G
Out of specification → Replace the valve
spring.
a. Compressed valve spring force
b. Installed length
Installed
force (intake)
147.00–169.00 N (33.05–37.99
lbf) (14.99–17.23 kgf)
Installed
force (exhaust)
147.00–169.00 N (33.05–37.99
lbf) (14.99–17.23 kgf)
Installed length
31.00 mm (1.22 in)
3. Measure:
Valve spring tilt "a"
G
Out of specification → Replace the valve
spring.
Spring tilt limit
Spring tilt (intake)
2.5 °/1.6 mm
Spring tilt (exhaust)
2.5 °/1.6 mm
5-22
compression spring
compression spring