GENERAL OPERATION
Operation - 17
Cutting Height Adjustment
Always set the parking brake, shut off the tractor
engine, remove the ignition key, and ensure all
moving parts have stopped before checking
mower deck or blade condition, or attempting
any repair or adjustment.
The cutting height of the mower decks is controlled
by the setting of the mower front wheels and the
deck rear rollers.
1. Lift the mower decks to the service position.
(Refer to the “Deck Flip-up Procedure” in the
service section of this manual.)
2. Determine the desired cutting height. Refer to
the decals located on the left and right sides of
the MJ840 for the settings required to obtain the
desired cutting height.
3. Remove the 4 front wheel axle bolts, and rein-
stall the wheels at the appropriate setting.
Torque bolts to 31 ft-lbs (42 Nm).
4. Remove the 2 bolts holding the roller brackets
to the decks (1 bolt on both sides of each roller).
Reinstall the bolts at the desired cutting height.
Torque bolts to 31 ft-lbs (42 Nm).
Mower Front Wheel Path Adjustment
Always set the parking brake, shut off the tractor
engine, remove the ignition key, and ensure all
moving parts have stopped before checking
mower deck or blade condition, or attempting
any repair or adjustment.
The front caster wheels on the left and right sides
can be repositioned for different applications.
For maximum deck overhang, move the caster
wheels to the furthest inboard position.
For maximum pass-to-pass consistency, and to
achieve the best cut quality, move the caster wheels
to the furthest outboard position.
The left and right wheels may be set differently from
each other as the application requires.
Upon repositioning the front caster wheels, torque
the mounting bolts to 31 ft-lbs (42 Nm).
Anti-Scalp Roller Adjustment
There are three positions for mounting the MJ840
anti-scalp rollers. The five rollers should all be
mounted at the same height.
1
2
3
When cutting between 3/4” (19 mm) and 1-1/4” (32
mm), install the anti-scalp rollers in position 1 for
best performance.
When cutting between 1-1/2” (38 mm) and 2-1/4”
(57 mm), install the anti-scalp rollers in position 2 for
best performance.
When cutting between 2-1/2” (64 mm) and 3-1/2”
(89 mm), install the anti-scalp rollers in position 3 for
best performance.
Upon repositioning the anti-scalp rollers, torque the
mounting bolts to 75 ft-lbs (102 Nm).
Mulching Kit (Optional Accessory)
Mulching procedures may vary greatly due to cli-
mate, type of grass, and soil conditions. It is gener-
ally best to mow frequently and in dry conditions.
Leaves are usually mulched and dispersed better
when some grass is cut with the leaves.
Mulching often requires more power than normal
mowing. When mulching wet and/or thick grass,
more frequent cleaning of the underside of the deck
is necessary.
Blades must be sharp and in good condition for
best results.
