HYOSUNG MS3 250 Sercie Manual page 62

3-19 ENGINE
▣ ▣ VALVE STEM RUNOUT
Check the valve stem for abnormal wear or bend.
Support the valve using a V-blocks and measure the
valve stem runout using the dial gauge, as shown.
If the service limit is exceeded or abnormal condition
exists, replace the valve with a new one.
Valve stem runout
Cylinder head
(IN. & EX.) distortion
Dial gauge : 09900-20606
Magnetic stand : 09900-20701
V-block : 09900-21304
▣ ▣ TAPPET & SHIM WEAR
When measuring the valve clearance, the clearance
should be within the standard range.
Valve clearance
Intake valve
Exhaust valve
● Inspect the tappet for wear and scratch.
If modification or scratch is present, replace the
tappet.
● 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 nar-
row please replace the present shim into thin
shim. (Refer to page 9-37∙38)
▣ ▣ 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.
Service limit
0.05 mm (0.002 in)
Standard (When cold)
0.1 ~ 0.2 mm
(0.004 ~ 0.008 in)
0.2 ~ 0.3 mm
(0.008 ~ 0.012 in)