BBM MZ SERIES ZERO-TURN MOWER. Manual - part 9

SECTION 6: CUTTING DECK

Deck belt removal:

Deck belt installation: 

1) Follow steps 1 and 2 from the deck removal section.

2) Take off both pulley covers and route the belt by

following the belt route sticker.

3) The easiest way to finish running the belt is routing

the belt through the deck pulleys and carefully
slipping the belt onto the clutch in the rear of the
engine.

4) Verify that the belt is routed properly as improper

routing can damage the spindles as well as the
engine.

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4

Remove Pulley Cover

Belt Route

1) Remove ignition key.

2) Raise the deck to its highest position.

3) Remove the right pulley cover.

4) While lifting up on the belt (as shown in the

photograph), rotate the pulley until the belt is free of
the pulley. Exercise caution while performing this step
as fingers can easily become caught between the belt
and pulley.

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35

Leveling the Deck: 

1)

Start on a flat, level surface and set the air pressure

in all four tires to 12 psi.

2)

Loosen the four bottom deck hanger bolts using a
9/16” wrench.

3)

Using the deck adjustment foot assist pedal, raise
the deck as high as it will go.  Place two 2x4s, with
2” side facing up, to create 4” of space underneath
the deck.  Make sure the 2x4s are long enough to
support both the front and back of the deck AND are
away from deck wheels.  Place a ¼” spacer on each
2x4 under the REAR of the deck to obtain proper
pitch.

4)

With the deck still raised, turn the height adjustment
knob to 3.5 and lower deck onto the 2x4s.

5)

With deck still on 2x4s, tighten the four deck hanger
bolts while pressing down on the deck to reduce any
slack.

6)

Remove 2x4s.  Measure all four corners to ensure
deck is now level.  The rear should measure 4” with
the front measuring 3 ¾”.

7)

Raise the deck up and ensure the height adjustment
knob makes a full rotation.  If full rotation is made,
the deck is now level.

Line Setting Up with Side 
of Tank

The deck spring tension is critical. if the tension is too 
high, premature failure of the deck belt and blade 
spindles can occur. If the tension is too low, the belt can 
"jump off" or slip on the pulleys. This results in reduced 
cut quality and early belt failure.

Spring tension adjustments can be made by sliding the 
bolt shown above forward or backward in the slot of the 
deck. Belt tension should be 60-65 lbs. with the deck at its 
lowest setting.

Use a belt tension gauge to ensure the proper tension. Your 
dealer or service center will have a belt tension 
gauge or you can buy one (Part Number 041-9999-00).

Blade Shapening:

The blade on the top (see photo) was utilized long after 
replacement was required. In addition to a decline in cut 
Quality, failure to replace a worn or damaged blade creates 
a major safety hazard. Bad Boy recommends that blade 
sharpening be performed by a professional.

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37

Blade Removal:
To change blades, it may be easier to use a piece of wood to 
keep the blade from turning so that the bolt can be loosened. 
Use a 15/16" socket and impact drill, or a wrench and an 
extension to gain more leverage. You might need to put a 3/4" 
wrench on top of the pulley bolt to keep the blade from 
spinning. Bolts used have right-handed threads.

Re-torque the blade bolts to 90-110 lbs.

The blade spindles contain a sealed ball earing inside the top 
and bottom of the spindle. The bearings are replaceable for a 
more cost effective repair.