Push Lawn Mower Operator's Manual

15
SECTION 8: SERVICE AND MAKING ADJUSTMENTS
Blade Care
Periodically inspect the blade adapter and pulley for
cracks, especially if you strike a foreign object. Replace
when necessary.
WARNING: When removing the cutting
blade for sharpening or replacement,
protect hands by using heavy gloves or a
thick rag to grasp the cutting blade.
• Disconnect spark plug wire from spark plug.
• Turn mower on its side making sure that the air filter
and the carburetor are up.
To Remove Blade
• Remove the bolt and bell washer that hold the
blade-pulley assembly to the engine crankshaft.
See Figure 20. Remove the assembly from the
crankshaft.
• Remove the two bolts and lock nuts from the blade
assembly.
• Remove the blade from the blade adapter and
pulley.
To Replace Blade:
• Before reinstalling the blade-pulley assembly to the
unit, lubricate the engine crankshaft and the inner
surface of the blade adapter with light oil or engine
oil.
• Also lubricate the bolt holes, bolt and the inner
surface of the nuts.
• Install the blade adapter on the pulley with the “star”
away from the pulley. See Figure 20.
Figure 20
• Place the new blade on the blade adapter with the
side marked bottom (has a part number) facing
away from the adapter.
• Secure the blade to the assembly with two hex
bolts and lock nuts. Tighten the hex bolts to the
recommended torque. Refer to ‘Blade Mounting
Torque’ section below.
• Install the blade assembly on the engine
crankshaft. Secure with the hex bolt and bell
washer (cupped side of washer to blade) and
tighten to the recommended torque. Refer to ‘Blade
Mounting Torque’ section below.
IMPORTANT: The bolt used to secure the blade to the
engine is specially heat-treated. Do not substitute. To
order replacement bolt, refer to the parts list in the back
of this manual.
WARNING: To ensure safe operation of
your unit, all nuts and bolts must be
checked periodically for correct tightness.
To Sharpen Blade:
• The blade can be sharpened with a file or on a
grinding wheel. Do not attempt to sharpen the
blade while it is still on the mower.
• Follow the original angle of grind as a guide. Make
sure that each cutting edge receives an equal
amount of grinding to prevent an unbalanced blade.
An unbalanced blade will cause excessive vibration
when rotating at high speeds, may cause damage to
the mower and could break, and may causing personal
injury. Test the blade by balancing it on a round shaft
screwdriver or a blade balancer.
• If the blade is not balanced, remove metal from the
heavy side until it balances evenly.
Blade Mounting Torque:
Blade adapter bolts: 120 in.lbs. minimum, 150 in.lbs.
maximum.
Center bolt: 450 in.lbs. minimum, 600 in.lbs. maximum.
Battery Pack Replacement
(Electric Start Units Only)
Remove the battery pack from the handle panel for
replacement only. Do not separate the batteries for any
reason. Dispose of batteries properly.
WARNING: Batteries contain sulfuric acid
which may cause burns. Do not short
circuit or mutilate batteries in any way. Do
not put batteries in fire as these may burst
or release toxic materials.
Lock Nut
Lock Nut
Pulley
Assembly
Blade
Adapter
Blade
Bell
Washer
Hex Bolt
Hex Bolt
Hex Bolt