Suzuki UY125 Service Manual page 64

3-30 ENGINE
VALVE SPRING INSPECTION
The force of the coil spring keeps the valve seat tight. A weak-
ened spring results in reduced engine power output and often
accounts for the chattering noise coming from the valve mecha-
nism.
Check the valve springs for proper strength by measuring their
free length and also by the force required to compress them. If
the spring length is less than the service limit or if the force
required to compress the spring does not fall within the specified
range, replace both the inner and outer springs as a set.
& Valve spring free length (IN. & EX.)
Service Limit: 32.9 mm
$ 09900-20102: Vernier calipers
& Valve spring tension (IN. & EX.)
Standard: 118 N (12.0 kgf)/26.8mm
CAMSHAFT CAM WEAR
Check for abnormal surface damage or wear on the cam face.
Measure the cam height H with a micrometer.
Replace the camshaft if found worn down to the service limit.
& Cam height H
Service Limit (IN.) : 27.62 mm
(EX.) : 27.47 mm
$ 09900-20202: Micrometer (25 – 50 mm)
CAMSHAFT BEARING
Rotate the camshaft bearing outer race by finger to inspect for
abnormal play, noise and smooth rotation.
Replace the bearing in the following procedure if there is any-
thing unusual.
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118 N (12.0 kgf)
26.8 mm