HYOSUNG MS3 250 Sercie Manual page 63

▣ ▣ VALVE HEAD RADIAL RUNOUT
Support the valve using a V-block and measure the
valve head radial runout using the dial gauge, as
shown. If the runout exceeds the service limit,
replace the valve with a new one.
Valve head radial
Cylinder head
runout (IN. & EX.) distortion
Dial gauge : 09900-20606
Magnetic stand : 09900-20701
V-block : 09900-21304
▣ ▣ VALVE STEM DEFLECTION
Lift the valve about 10 mm (0.39 in) from the valve
seat. Measure the valve stem deflection in two direc-
tions, "X" and "Y", perpendicular to each other.
Position the dial gauge as shown.
If the deflection exceeds the service limit, determine
whether the valve or the guide should be replaced
with a new one.
Valve stem deflection
IN.
EX.
Dial gauge : 09900-20606
Magnetic stand : 09900-20701
▣ ▣ VALVE STEM DIAMETER
Measure the valve stem outside diameter using the
micrometer.
If the diameter measured exceeds the standard,
replace the valve.
Valve stem
diameter
4.465 ~ 4.480 mm
IN.
(0.1758 ~ 0.1764 in)
4.455 ~ 4.470 mm
EX.
(0.1754 ~ 0.1760 in)
Micrometer(0~25 mm) : 09900-20201
Service limit
0.03 mm (0.0012 in)
Service limit
0.35 mm
(0.014 in)
0.35 mm
(0.014 in)
Standard
4.475 ~ 4.490 mm
(0.1762 ~ 0.1768 in)
4.455 ~ 4.470 mm
(0.1754 ~ 0.1760 in)
ENGINE 3-20