MTD 979K Operator's Manual page 13

Lubrication
Refer to the lubrication chart in Figure 13.
BladeControlHandle
• Lubricate the pivot points on the blade control
handle at least once a season with light oil. The
blade control must operate freely in both directions.
Rear DischargeDoor
• Lubricate the torsion spring and the pivot point on
each end of the rear discharge door using a light oil.
This will prevent rusting of the discharge door.
Wheels
• Lubricate the wheels and bearings, if so equipped,
at least once a season with light oil or engine oil.
Also, if the wheels are removed for any reason,
lubricate the surface of the axle bolt and the inner
surface of the wheel with light oil.
Engine
• Follow the engine manual instructions and
recommended schedule for lubricating engine
components.
Lubricate
Lubricate
Lubricate
Figure 13
SECTION 8: SERVICING THEMOWER
WARNING:
Always stop the engine and
disconnect the spark plug wire before
performing any maintenance work or
adjustments on your lawn mower.
BladeCare
WARNING: When removing the cutting
blade for sharpening or replacement, protect
your hands with a pair of heavy gloves or use a
heavy rag to hold the blade.
Periodically inspect the blade adapter for cracks,
especially if you strike a foreign object. Replace when
necessary.
Removingthe Blade
• Disconnect spark plug wire from spark plug.
• Turn mower on its side making sure that the air filter
and the carburetor are up.
• Remove the bolt and the blade bell support which
hold the blade and the blade adapter to the engine
crankshaft. See Figure 14.
• Remove the blade and the adapter from the
crankshaft.
Sharpeningthe 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.
_ ARNING: An unbalanced blade will cause
excessive vibration when rotating at high
speeds. It may cause damage to the mower,
and could break causing personal injury.
Balancingthe Blade
• The blade can be tested by balancing it on a round
shaft screwdriver. Remove metal from the heavy
side until it balances evenly. It is recommended that
the blade always be removed from the adapter
when testing for balance.
Installing the Blade
• Before reinstalling the blade and the blade adapter
to the unit, lubricate the engine crankshaft and the
inner surface of the blade adapter with light oil.
• Be sure to install the blade with the side of the
blade marked "Bottom" (or with part number) facing
the ground when the mower is in the operating
position.
13