Ferris 300e Operator's Manual page 21

• The air lifts are worn (B, Figure 32) and the notch (C)
is .25" (6,35 mm) deep or greater.
• The mower blade is broken or bent.
3. If the mower blades are not sharp but are in good
condition, sharpen the mower blades. See Mower Blade
Sharpening.
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Mower Blade Sharpening
WARNING
Fire and Thrown Objects Hazard
Grinding mower blades throws sparks and fine metal particles
that are capable of igniting flammable materials and vapors,
and that can injure unprotected eyes.
• Remove all flammable materials from the area where
grinding will occur.
• Always wear safety glasses or goggles when grinding
mower blades.
1. Sharpen mower blades with a grinder, hand file, or
electric blade sharpener.
2. Sharpen the blade by removing an equal amount of
material from the cutting edge of each end of the blade.
3. Keep the original cutting edge angle (A, Figure 33) when
grinding. DO NOT change the angle of the cutting edge.
4. The mower blade should have a maximum of 1/64" (0,40
mm) cutting edge (B) or less.
33
Mower Blade Balancing
WARNING
Thrown Objects Hazard
An unbalanced mower blade can create excessive vibration
and damage the unit, or cause mower blade failure resulting
in thrown debris.
• Make sure that the mower blade is balanced before
installation.
1. Clean the mower blade to remove any debris.
2. Tighten a nail in a bench vise. Hang the mower blade on
the nail, and set the blade in a level, horizontal position
as shown in Figure 34.
3. If either end of the mower blade moves downward, that
end is heavier than the other. Sharpen the heavy end
until the blade stays in the level, horizontal position. See
Mower Blade Sharpening.
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