Craftsman 917.387470 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 rub-
ber.
• 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 bent or damaged
blades.
TO REMOVE BLADE
1. Disconnect spark plug wire from spark
plug and place wire where Stcannot
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 hard-
ware (bolt, lock washer and hardened
washer).
NOTE: Remove the blade adapter and
check the key inside hub of blade adapter.
The key must be in good condition to work
properly. Replace adapter if damaged.
TO REPLACE BLADE
1. Position the blade adapter on the en-
gine crankshaft. Be sure key in adapter
and crankshaft keyway are aligned.
2. Position blade on the blade adapter
aligning the two (2) holes in the blade
with the raised lugs on the adapter.
3. Be sure the trailing edge of blade (op-
posite sharp edge) is up toward the
engine.
4. Install the blade bolt with the lock
washer and hardened washer into
blade adapter and crankshaft.
5. 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 shaft
bolt / \
washer Trailing edge Blade adapter
TO SHARPEN BLADE
NOTE: We do not recommend sharpening
blade - but if you do, be sure the blade is bal-
anced. 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
(If purchased as an accessory)
• The grass catcher may be hosed with
water, but must be dry when used.
• Checkyour grass catcher often for damage
or deterioration. Through normal use it will
wear. If catcher needs replacing, replace
only with approved replacement 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 SF-SJ. Select the
oil's SAE viscosity grade according to your
expected operating temperature.
SAE VtSCOSITY GRADES
lO0
TEMPERATURE RANGE ANTICIPATED BEFORE NEXT G_L CHANGE
NOTE: Although multi-viscosity oils (5W30,
10W30 etc.) improve starting in cold weather,
they will result in increased oil consumption
when used above 32°F. Check your engine
oil level more frequently to avoid possible
12engine damage from running low on oil.