HYOSUNG 2010 ST7, Service Manual

Page: 70 / 298

3-23 ENGINE
Remove the crankshaft by using the special tool.
Cylinder head
distortion
Service limit
0.05 mm (0.002 in)
Valve head thickness
Service limit
0.5 mm (0.02 in)
Valve stem runout
Service limit
0.05 mm (0.002 in)
ENGINE COMPONENT
INSPECTION AND SERVICE
VALVE FACE WEAR
Visually inspect each valve face for wear. Replace any
valve with an abnormally worn face. The thickness of
the valve face decreases as the face wears. Measure
the valve head thickness . If it is out of specification,
replace the valve with a new one.
VALVE STEM RUNOUT
Check the valve stem for abnormal wear or bend.
Place the valve on V-blocks and measure runout.
If the service limit is exceeded or abnormal condi-
tion exists, replace the valve.
CYLINDER HEAD DISTORTION
Decarbonate in combustion chamber.
Check the gasket surface of the cylinder head for distor-
tion with a straightedage 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 head.
Crankcase separator : 09920-13120
Dial gauge : 09900-20606
Magnetic stand : 09900-20701
V-block : 09900-21304
CAUTION
Be sure to identify each removed part as to its
location, and lay the parts out in groups desig-
nated as Front cylinder , Rear cylinder ,
E x h a u s t , Intake , so that each will be
restored to the original location during assembly.
Thickness gauge : 09900-20806
Vernier calipers : 09900-20101