HYOSUNG RX 125 Service Manual page 43

3-13 ENGINE
VALVE HEAD RADIAL RUNOUT
Place the dial gauge at right angles to the valve head,
and measure the valve head radial runout.
If it measures more than limit, replace the valve.
Valve head radial runout
VALVE GUIDE-VALVE STEM
CLEARANCE
Measure the clearance in two directions, "X"and "Y" ,
perpendicular to each other, by rigging up the dial
gauge as shown. If the clearance measured exceeds
the limit specified below, then determine whether the
valve or the guide should be replaced to reduce the
clearance to within the standard range:
valve Standard
IN 0.010~0.037 mm
EX 0.030~0.057 mm
VALVE STEM WEAR
If the valve stem is worn down to the limit, when measured
with a micrometer, and the clearance is found to be in
excess of the limit previously indicated, replace the valve, if
the stem is within the limit, then replace the valve guide. After
replacing valve or guide, be sure to recheck the clearance.
Micrometer (0~25 mm) : 09900-20205
VALVE STEM O.D.
● Check face into end of valve stem and wear.
valve
IN
EX
CAUTION
Inspect the valve stem end face for pitting and wear. If
pitting or wear of the stem end face are present, the
valve stem end may be resurfaced, providing that the
length ① will not be reduced to less than 3.38 mm. If
this length becomes less than 3.38 mm, the valve must
be replaced. After installing a valve whose stem end
has been ground off as above, check to ensure that the
face ② of the valve stem end is above the cotters ③.
Service limit 0.03 mm
Service limit
0.35 mm
0.35 mm
Standard
4.975~4.990 mm
4.955~4.970 mm