Shindaiwa AH254 - Manual (Page 16)

16
Maintenance (continued)
135-Hour Maintenance
Combustion chamber should be
■
decarbonized, and the valve clear-
ance should be adjusted. It is highly
recommended that this is done
by a Shindaiwa-trained service
technician.
Replace the spark plug annually:
■
Use only the type recommended in
the ”Specifications” section or an
equivalent resistor type spark plug
of the correct heat range. Set spark
plug electrode gap to 0.6 mm.
IMPORTAnT!
If a new gasket is not available and/
or the old gasket is not damaged, the
old gasket may be reused. Never use
cracked or damaged gaskets!
Turn engine over several times, 6.
and return to TDC-compression.
Recheck with proper feeler gauge to
make sure clearance adjustment did
not change as a result of tightening
the locknut. Readjust as necessary.
Replace rocker arm cover gasket 7.
to assure proper sealing and install
cover.
Remove cylinder cover, rocker arm 1.
cover, and spark plug. Rotate the
crankshaft while observing the pis-
ton through the spark plug open-
ing. When the piston is at the top of
the compression stroke (TDC), the
valves can be adjusted.
Loosen adjuster locknut so that the 2.
2.5 mm Allen socket head adjustment
screw can turn freely.
Insert 0.10 mm feeler gauge between
3.
valve stem tip and rocker arm.
Turn adjustment screw (clockwise =
4.
tighter, counter-clockwise = looser)
until feeler gauge is almost snug.
Back off just enough to allow gauge
to slip out with limited resistance.
While holding the adjustment screw
5.
in place with the Allen driver, tighten
the locknut with a wrench.
CAUTIOn!
Performing a valve adjustment
■
incorrectly may cause hard
starting and/or can damage the
engine.
If you are unfamiliar with this
■
engine or uncomfortable with
this procedure, consult with an
authorized Shindaiwa servicing
dealer.
Valve Adjustment