Sears 770-7387F 247.78089 - Manual (Page 11)

When engine is drained of all oil, replace drain piug
securely.
• Refill with fresh oil. Above 32°, use oil labeled SAE
30W or 10W30. Below 32°, use oil labeled 5W20.
Capacity is approximately 1V2 pints. Refer to “Gas
and Oil Fill-Up” on page 8.
• Replace oil fill plug.
AIR CLEANER
The air cleaner prevents damaging dirt, dust, etc., from
entering the carburetor and being forced into the engine
and is important to engine life and performance.
Never run your engine without air cleaner complete­
ly assembled.
To Service Air Cleaner:
Clean cartridge at three month intervals or every 25
hours, whichever occurs first. See figure 15. Service
more often under dusty conditions.
• Loosen screws and tilt cover as illustrated.
• Carefully remove pre-cleaner and cartridge.
• Clean cartridge by tapping gently on a flat surface.
If very dirty, replace cartridge and pre-cleaner or
clean as follows:
Wash in a low or non-sudsing detergent and warm
water solution.
CAUTION: Do not use petroleum
solvents such as kerosene to clean cartridge.
Rinse thoroughly with flowing water from inside out
until water is clear.
Allow cartridge to stand and air dry thoroughly
before using. DO NOT OIL CARTRIDGE OR PRE­
CLEANER. DO NOT USE PRESSURIZED AIR TO
CLEAN OR DRY CARTRIDGE.
• Install cartridge and pre-cleaner. Then close cover
and fasten screws securely.
Foam
Filter
Cover
Wing
Nut
Paper
Filter
FIGURE 15.
CLEAN ENGINE
Clean engine periodically. Remove dirt and debris from
the cooling fins, air intake screen, and levers and
linkage with a cloth or brush. See figure 16. Cleaning
with a forceful spray of water is not recommended as
water could contaminate the fuel system.
A
WARNING: PERIODICALLY CLEAN MUF­
FLER AREA TO REMOVE ALL GRASS,
DIRT AND COMBUSTIBLE DEBRIS.
Air Intake
Screen
Levers
and Linkage
Coolingi
Fins
FIGURE 16.
SPARK PLUG
The spark plug should be cleaned and the gap reset
to .030" at least once a season or every 50 hours of
operation. See figure 17. Spark plug replacement is
recommended at the start of each season. Refer to
engine parts list for correct spark plug type.
NOTE: Do not wire brush or sandblast spark plug.
Spark plug should be cleaned by carefully scraping
electrodes.
MUFFLER
Do not operate the chipper-shredder without a muffler
or tamper with the exhaust system. Damaged mufflers
or spark arresters could create a fire hazard. Inspect
periodically, and replace if necessary. If your engine
is equipped with a spark arrester screen assembly,
remove every 25 hours for cleaning and inspection.
Replace if damaged.
CLEANING
• The chipper-shredder may be cleaned by running
water from a hose through the hopper assembly and
chipper chute with the engine running. Allow the
chipper-shredder to dry thoroughly.
• Wash the bag periodically with water. Allow to dry
thoroughly in the shade. Do not use heat.
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