3. TROUBLESHOOTING
47
Valve spring retainer
：
Push down the valve spring and move the retainer to the side so that valve stem slips through
the side hole.
Do not remove the valve spring
retainers while the cylinder head is
attached to the cylinder, or the valves
will drop into the crankcase.
2
）
Inspect/ Service/ Repair
：
①
Valve stem outside diameter
Inspect the valve stem outside diameter with the
micrometer, if finding out of the standard or service limit,
or if visually inspecting the burn and damaged on the
valve face, please replace with new one.
Standard
Service limit
5.48mm
（
IN
）
5.44mm
（
EX
）
5.318
（
IN
）
5.275
（
EX
）
②
Valve spring free length
Measure the free length of the valve springs. If out of the standard or service limit. Please
replace the spring
Standard
Service limit
34mm
32.5mm
