Blade Care - Craftsman 917.370928 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.
DRIVE WHEELS
Check rear drive wheels each time before
you mow to be sure they move freely.
The wheels not turning freely means trash,
grass cuttings, etc. are in the drive wheel area
and must be cleaned to free drive wheels.
If necessary to clean the drive wheels, be
sure to clean both rear wheels.
BLADE CARE
For best results, mower blade must be
kept sharp. Replace a bent or damaged
blade.
A CAUTION: Use only a replacement
blade approved by the manufacturer of
your mower. Using a blade not approved
by the manufacturer of your mower is
hazardous, could damage your mower
and void your warranty.
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, hardened washer).
6. Remove debris shield.
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
engine crankshaft. Be sure key in
adapter and crankshaft keyway are
aligned; and that the drive belt is
inside the tab of the belt retainer.
2. Install debris shield.
3. Position blade on the blade adapter.
IMPORTANT: To ensure proper assembly,
center hole in blade must align with star
on blade adapter.
14
4. Be sure the trailing edge of blade (oppo-
site sharp edge) is up toward the engine.
5. Install the blade bolt with the lock
washer and hardened washer into
blade adapter and crankshaft.
6. 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.
Belt
adapter
z z_1
Crank-
shaft
keyway
Trailing
shield edge
washer
Lockwasher
Blade bolt
TO SHARPEN BLADE
NOTE: We do not recommend sharpening
blade - but if you do, be sure the blade is
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, you will need
a 5/8" diameter steel bolt, pin, or a cone
balancer. (When using a cone balanc-
er, follow the instructions supplied with
balancer.)
NOTE: Do not use a nail for balancing
blade. The lobes of the center hole may
appear to be centered, but are not.
• Slide blade on to an unthreaded portion
of the steel bolt or pin and hold the
bolt or pin parallel with the ground. 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.
Center hole
5/8" bolt or pin
Blade