Shindaiwa M254 Owner's/Operator's Manual page 15

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.
The valve clearance should be adjusted. It is highly recommended that this
is done by a Shindaiwa-trained service technician.
Valve adjustment
1. Remove cylinder cover, rocker arm
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.
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.
■
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!
2. Loosen adjuster locknut so that the
2.5 mm Allen socket head adjustment
screw can turn freely.
3. Insert 0.10 mm (0.004") feeler gauge
between valve stem tip and rocker
arm.
4. Turn adjustment screw (clockwise =
tighter, counter-clockwise = looser)
until feeler gauge is almost snug. Back
off just enough to allow gauge to slip
out with limited resistance.
5. While holding the adjustment screw in
place with the Allen driver, tighten the
locknut with a wrench.
6. Turn engine over several times, 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.
7. Replace rocker arm cover gasket
to assure proper sealing and install
cover.
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!
15