10.3 Inspection
VALVE SPRING FREE LENGTH
Measure the free length of the valve springs.
Service limit
HRA536 - HRD536/K1/K2
HRD535/K1/K2
IN / EX: 32.5 mm
IN / EX: 29 mm
If the spring free length is shorter than service limit, replace the valve spring.
VALVE SEAT WIDTH
Measure the valve seat width.
Service limit
IN / EX: 2.0 mm
If the valve seat width is over the service limit, recondition the valve seat (ch. 10.5).
CYLINDER HEAD WARPAGE
Remove the carbon deposits from the combustion chamber.
Clean off any gasket material from the cylinder head surface.
Check the spark plug hole and valve areas for cracks. Check the cylinder head for warpage
with a straight edge and a feeler gauge.
Service limit
0.10 mm
VALVE STEM O.D.
Inspect each valve for face irregularities, bending or abnormal stem wear. Replace the
valve if necessary.
Measure and record each valve stem O.D.
Service limit
IN: 5.318 mm
EX: 5.275 mm
Replace the valves if their O.D. is smaller than the service limits.
[1]
STRAIGHT EDGE
[2]
FEELER GAUGE
- 68 -
HRA536 - HRD535 - HRD536
- CYLINDER HEAD / VALVES
[1]
[2]