HYOSUNG RX 125 Service Manual page 47

3-17 ENGINE
VALVE SPRINGS
Check the springs for strength by measuring their
free lengths and also the force required to com-
press them. If the limit indicated below is exceed-
ed by the free length reading or if the measured
force does not fall within the range specified,
replace with a HYOSUNG spring as a set.
Valve spring free length
Valve spring free length
IN. & EX.
Valve spring tension(Assembly condition)
Valve spring tension
IN. & EX.
CYLINDER DISTORTION
Check the gasketed surface of the cylinder for dis-
tortion with a straightedge and thickness gauge,
taking a clearance reading at several places as
indicated. If the largest reading at any position of
the straightedge exceeds the limit, replace the
cylinder.
Cylinder distortion
CYLINDER BORE
Measure the cylinder bore diameter at six places. If
any one of the measurements exceeds the limit,
overhaul the cylinder and replace the piston with an
oversize, or replace the cylinder.
Cylinder gauge set : 09900-20508
Cylinder bore diameter
PISTON DIAMETER
Using a micrometer, measure the piston outside
diameter at the place 15 mm from the skirt end as
shown in Fig. If the measurement is less than the
limit, replace the piston.
Micrometer (50~75 mm) : 09900-20203
Piston diameter
Piston oversize
CAUTION
Using a soft-metal scraper, decarbon the crown
of the piston. Clean the ring grooves similarly.
Service limit
41.65 mm
Standard
13.6~16.6 kg / 36.6 mm
Service limit 0.05 mm
Service limit 57.080 mm
Service limit 56.880 mm
0.5, 1.0 mm
15 mm