HYOSUNG 2010 ST7, Service Manual

Page: 72 / 298

3-25 ENGINE
Valve head radial
runout
Service limit
0.03 mm (0.0012 in)
Valve guide-valve stem clearance
Standard
0.020~0.047 mm
(0.0008~0.0019 in)
0.030~0.057 mm
(0.0012~0.0022 in)
Valve stem diameter
4.465~4.480 mm (0.1758~0.1764 in)
4.455~4.470 mm (0.1754~0.1760 in)
IN.
EX.
VALVE HEAD RADIAL
RUNOUT
Place a dial gauge as shown and measure valve
head radial runout.
If the service limit is exceeded, replace the valve.
VALVE STEM DIAMETER
Measure the valve stem outside diameter.
If the diameter measured exceeds the standard, replace
the valve.
VALVE GUIDE-VALVE STEM
CLEARANCE
Measure the clearance in the valve guide-valve stem, by
rigging up the dial gauge as shown. If the clearance is
measured exceeds the limit specified below, then deter-
mine whether the valve or the guide should be replaced
to reduce the clearance to within the standard range :
EX.
IN.
Inspect the tappet for wear and scratch.
If modification or scratch is present, replace the tap-
pet.
When you checked the valve clearance, if the valve
clearance is wide please replace the present shim
into thick one, if the valve clearance is narrow please
replace the present shim into thin shim.
(Refer to page 9-39 40)
SHIM KIND
There are 41 kinds of shim which thickness is increased
by each 0.025 mm from 1.20 mm to 2.20 mm.
Standard
Dial gauge : 09900-20606
Magnetic stand : 09900-20701
V-block : 09900-21304
Dial gauge : 09900-20606
Magnetic stand : 09900-20701
Micrometer(0~25 mm) : 09900-20201