Checking The Valve Springs - Yamaha VMX12 2001 Service Manual

VALVES AND VALVE SPRINGS
g. Apply Mechanic's blueing dye (Dykem) b
h. Install the valve into the cylinder head.
i. Press the valve through the valve guide and
j. Measure the valve seat width c again. If
EAS00241

CHECKING THE VALVE SPRINGS

The following procedure applies to all of the
valve springs.
1. Measure:
2. Measure:
b Installed length
4 - 30
onto the valve face.
onto the valve seat to make a clear impres-
sion.
the valve seat width is out of specification,
reface and lap the valve seat.
• valve spring free length a
Out of specification → Replace the valve
spring.
Valve spring free length limit
(intake and exhaust)
Inner valve spring
37.45 mm
Outer valve spring
38.90 mm
• compressed valve spring force
Out of specification → Replace the valve
spring.
Compressed valve spring force
(installed)
Intake and exhaust inner valve
spring
6.29 ~ 7.39 kg at 31.8 mm
Intake and exhaust outer valve
spring
13.3 ~ 15.7 kg at 33.8 mm
ENG