Cylinder Head Inspection; Valve/Valve Guide Check; Valve Spring Check - KYMCO DINK 125 Service Manual

6
. CYLINDER HEAD/VALVES
INSPECTION
Remove carbon deposits from the exhaust
port and combustion chamber.
＊
Be careful not to damage the cylinder
head mating surface.
Valve /Valve guide
Inspect each valve for bending, burning,
scratches or abnormal stem wear.
If any defects are found, replace the valve
with a new one.
Check valve movement in the guide.
Measure each valve stem O.D.
Measure each valve guide I.D.
Subtract each valve stem O.D. from the
corresponding guide I.D. to obtain the
stem-to-guide clearance.
Service limits:
＊
If the stem-to-guide clearance exceeds
the service limits, replace the cylinder
head is necessary.
Valve spring
Measure the free length of the inner and outer
valve springs.
Service Limit:
Inner: 29.3 mm (1.172 in)
Outer: 32 mm (1.28 in)
6-17
IN: 0.08 mm (0.0032 in)
EX: 0.1 mm (0.004 in)
DINK 50/ 125
Combustion Chamber
Exhaust Port