Craftsman 917.388820 Owner's Manual page 12

LAWN MOWER
Always observe safety rules when per-
forming any maintenance.
TIRES
• Keep tires free of gasoline, oil, or insect
control chemicals which can harm rubber.
• Avoid stumps, stones, deep ruts, sharp
objects and other hazards that may
cause tire damage.
BLADE CARE
For best results, mower blade must be kept
sharp. Replace a bent or damaged blade.
TO REMOVE BLADE
1. Disconnect spark plug wire from spark
plug and place wire where it cannot
come in contact with plug.
2. Turn lawn mower on its side. Make
sure air filter and carburetor are up.
3. Use a wood block between blade and
mower housing to prevent blade from
turning when removing blade bolt.
NOTE: Protect your hands with gloves
and/or wrap blade with heavy cloth.
4. Remove blade bolt by turning counter-
clockwise.
5. Remove blade and attaching hardware
(bolt, lock washer and hardened washer).
TO REPLACE BLADE
1. Position blade on the blade adapter
aligning the two (2) holes in the blade
with the raised lugs on the adapter.
2. Be sure the trailing edge of blade (oppo-
site sharp edge) is up toward the engine.
3. Install the blade bolt with the lock
washer and hardened washer into
blade adapter and crankshaft.
4. Use block of wood between blade and
lawn mower housing and tighten the
blade bolt, turning clockwise.
• The recommended tightening torque is
35-40 ft. Ibs.
IMPORTANT: Blade bolt is heat treated.
If bolt needs replacing, replace only with
approved bolt shown in the Repair Parts
section of this manual.
Blade adapter Crankshaft
Key _ keyway
Blade
Blade
bolt /
washer Trailing edge
TO SHARPEN BLADE
NOTE: We do not recommend sharpening
the blade - but if you do, be sure the blade
is balanced. Care should be taken to
keep the blade balanced. An unbalanced
blade will cause eventual damage to lawn
mower or engine.
• The blade can be sharpened with a file
or on a grinding wheel. Do not attempt
to sharpen while on the mower.
• To check blade balance, drive a nail into
a beam or wall. Leave about one inch of
the straight nail exposed. Place center
hole of blade over the head of the nail.
If blade is balanced, it should remain in
a horizontal position. If either end of the
blade moves downward, sharpen the
heavy end until the blade is balanced.
GRASS CATCHER
• The grass catcher may be hosed with
water, but must be dry when used.
• Check your grass catcher often for dam-
age or deterioration. Through normal
use it will wear. If catcher needs replac-
ing, replace only with approved replace-
ment catcher shown in the Repair Parts
section of this manual. Give the lawn
mower model number when ordering.
ENGINE
Maintenance, repair, or replacement of
the emission control devices and systems,
which are being done at the customers ex-
pense, may be performed by any non-road
engine repair establishment or individual.
Warranty repairs must be performed by an
authorized engine manufacturer's service
outlet.
LUBRICATION
Use only high quality detergent oil rated
with API service classification SF-SJ.
Select the oil's SAE viscosity grade
according to your expected operating
temperature.
SAE VISCOSITY GRADES
"F -20 0 80 _ 40 60 80 100
_MPERATURE RANGE ANTICIPATED BEFORE NEXT OIL CHANGE
NOTE: Multi-viscosity oils (5W30, 10W30
etc.) improve starting in cold weather, and
you should check your engine oil level fre-
quently to avoid possible engine damage
from running low on oil.
Change the oil after every 25 hours of
operation or at least once a year if the
shaft lawn mower is not used for 25 hours in
\
Blade adapter 12 °ne year.