Blade Care - Craftsman 917.388590 Owner's Manual

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, Iock 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
Lockwasher
Blade
/
, /
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
LUBRICATION
Use only high quality detergent oil rated with
API service classification SG-SL. Select the
oil's SAE viscosity grade according to your
expected operating temperature.
SAE VISCOSITY GRADES
20 ¢ 30 32 40 60 80 100
30 _0 0 0 10 20 30 40
TEMPERATURE RANGE ANTIC PATED BEFORE NEXT OIL CHANGE
NOTE: Although multi-viscosity oils
(5W30, 10W30 etc.) improve starting in
cold weather, these multi-viscosity oils will
result in increased oil consumption when
used above 32°R Check your engine oil
level more frequently to avoid possible
engine damage from running low on oil.
Check the crankcase oil level before
starting the engine and after each five (5)
hours of continuous use. Tighten oil plug
securely each time you check the oil level.
Blade
bolt
\
shaft
Hardene ..
washer Trailing edge Blade adapter 12