Gravely Promaster 320 Owner/Operator And Parts Manual page 14

2. Sharpen mower blade by removing an equal amount of
material from each end of mower blade. DO NOT
change angle of cutting edge or round the corner of the
mower blade.
3. Check mower blade balance.
Slide mower blade on an unthreaded bolt. A balanced
blade should remain in a horizontal position. If either
end of mower blade moves downward, sharpen the
heavy end until blade is balanced.
4. Install mower blade(s) on unit (See Mower Blades on
page 13).
ADJUSTING ANTI-SCALP ROLLERS
The anti-scalp rollers are set at the factory for typical
mowing height, but can be adjusted for high or low cutting
conditions.
Rollers are intended to prevent lawn scalping, not to control
cutting height.
For a very high cutting height, set the rollers in their lowest
position on the bracket (figure 14).
For a very low cutting height, set the rollers in their highest
position on the bracket.
All rollers should be set at the same height.
LEVELING THE MOWER DECK
These adjustments should be made on a level surface with
the tires inflated to the correct air pressure.
Check Blade Level and Pitch
1. Raise mower deck to a 3 in. (7.62 cm) cutting height.
2. Shut off engine. Engage parking brake. Remove the
ignition key.
NOTE: Place blocks under the bottom edge of the deck, not
under the reinforcement bar welded along deck face
(Figure 15).
Lowest
Mowing
Position
Highest
Mowing
Position
Figure 14
DO NOT place
blocks under
reinforcement bar.
Figure 15
3. Place blocks at each corner of the deck to support the
weight of the deck.
4. Turn the blades so the blade ends point left to right
across the width of the deck.
5. Measure the distance between the ground and cutting
edge of the blade on the left blade (Left position in
figure 16) and on the right blade (Right position in
figure 16). Distances should be within 3/16 in. (4.7 mm).
If they are not, raise the low side of the deck using the
height adjusters on the deck lift brackets (see figure 17).
6. After deck is level side to side, check the deck front to
back pitch.
7. Turn the blades so the blade ends point front to back as
shown in figure 16.
8. Measure the distance between the ground and the
cutting edge of the middle blade at the front of the deck
(Front position in figure 16) and between the ground the
cutting edge of the left and right blades at the rear of the
deck (Rear position in figure 16).
9. The cutting edge at the front of the deck (Front position
in figure 16) should be 1/8 in. (3.18 mm) lower than the
cutting edges at the rear of the deck (Rear position in
figure 16).
10. If measurements are out of range, raise the low side of
the deck using the height adjusters on the deck lift
brackets (see figure 17). Be sure to raise the deck
evenly to keep the deck level side to side.
NOTE: Pitching the front of the blades lower than the rear
provides a balance between cut quality and the power
needed to cut grass. Certain cutting conditions require the
deck to be pitched with the rear of the blades lower than the
OF3160 front. Heeling the deck this way requires more engine power
but can provide better cut quality.
11. Remove the blocks from under the deck.
OD5255
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