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MAINTENANCE
Place the new blade on the shaft against the fan assembly.
Make sure it is installed with the curved ends pointing
up toward the mower deck and not down toward the
ground.
Replace the blade insulator and spacer, then thread the
blade nut on the shaft and finger tighten.
NOTE:
Make certain all parts are replaced in the exact
order in which they were removed.
Torque the blade nut down using a torque wrench
(not provided) to ensure the bolt is properly tightened.
The recommended torque for the blade nut is 450-
600 in. lbs.
SHARPENING THE BLADE
See Figure 14.
For best mowing performance, the mower blade must be
kept sharp. A dull blade does not cut grass evenly and over-
loads the motor. Under normal circumstances, sharpening
the blade twice during the mowing season is usually suf-
ficient. However, if your lawn has sandy soil, more frequent
sharpenings may be required.
Following the instructions in the
Replacing the Cutting
Blade
section, remove the mower blade. DO NOT attempt
to sharpen the blade while it is attached to the mower.
WARNING:
When removing, inspect the blade carefully. If blade is
bent or damaged, replace immediately with a new blade.
Failure to replace a bent or damaged blade could cause
an accident resulting in possible serious injury.
Using a fine-tooth file or stone, sharpen cutting edges
on both ends of the blade, removing equal amounts of
material from both ends.
BALANCING THE BLADE
See Figure 15.
When sharpening, care should be taken to keep the blade
balanced. An unbalanced blade will cause excessive vibra-
tion when the mower is running. This vibration will eventually
cause damage to the mower, especially the motor.
To check the blade balance:
Clamp a screwdriver horizontally in a vise as shown.
NOTE:
If a vise is not available, a straight nail can also
be used.
Place the center hole of blade on the screwdriver (or nail)
shank.
If blade is balanced, it will remain in a horizontal position.
If either end of the blade drops downward, sharpen the
heavy side until the blade is balanced.
Fig. 13
Fig. 14
Fig. 15
BLADE INSULATOR
BLADE NUT
SPACER
BLADE
SHAFT
FAN ASSEMBLY
Summary of Contents for UT13218
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