13
Gearcase Protector (P/N
72958-16210)
Nut
Inspect the Gearcase Protector
The metal gearcase protector (p/n 72958-
16210) is installed to protect the gearcase
flange from damage when working close to
sidewalks or other abrasive surfaces, and
should be routinely inspected for damage
or excessive wear.
When replacing the protector, inspect to be
sure that both of the protector mounting
screws are firmly tightened and each screw
is locked in place with a nut as shown.
CAUTION!
The D-shaped shim washer must be
positioned with its at edge toward the
shaft tube.
D-shaped Shim
Washer
Flat (toward
tube)
Shaft
Tube
Gearcase
26024
Figure 23
Figure 24
139/150-Hour Maintenance
Maintenance after rst 139-hours,
then every 150-hours thereafter.
Combustion chamber should be decar-
bonized, and the valve clearance should
be adjusted. It is highly recommended
that this is done by a Shindaiwa-trained
service technician.
Replace the spark plug annually: Use
only NGK CMR5H or equivalent resis-
tor type spark plug of the correct heat
range. Set spark plug electrode gap to
0.024-0.028 inch (0.6 -0.7 mm).
NOTE:
The NGK CMR5H also meets the requirements
for electro magnetic compliance (EMC).
Valve Adjustment
1. Remove cylinder cover, rocker arm cover,
and set piston at TDC-compression.
2. Loosen adjuster locknut so that the 2.5
mm Allen socket head adjustment screw
can turn freely.
3. Insert feeler gauge .004” (0.10 mm) for
both intake and exhaust 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.
7. Replace rocker arm cover gasket to as-
sure proper sealing and install cover.
IMPORTANT!
If new gasket is not available and/or old
gasket is not damaged, old gasket may be re-
used. Never use cracked or damaged gaskets!
CAUTION!
Performing a valve adjustment incor-
rectly 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.
5. While holding adjustment screw in place with
Allen driver, tighten locknut with 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 locknut. Readjust
as necessary.
50-Hour Maintenance (continued)