Cutting Decks - MTD Garden Tractors User Manual

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CUTTING DECK PERFORMANCE
Operation * Problems * Solutions
WALK-BEHINDS AND LAWN AND GARDEN TRACTORS
THE FOLLOWING CONDITIONS CAN AFFECT THE QUALITY OF
TIRE PRESSURE VARIATION: The air pres-
sure should be equal on both front and rear
tires, approximately 12-13 lbs. air pressure
regardless of the size tire on lawn and garden
tractors.
DECK WHEELS INCORRECTLY SET: The
deck wheels should be set evenly so that the
pitch of the cutting blades will not be affected.
If any difference is required for a better cut on
some walk-behind mowers, the front height
adjuster can be one position lower to assure
that you are cutting with the front of the blade.
If the deck is slightly lower in the rear you will
tend to cut the grass at the rear of the mower.
This causes the grass to be thrown to the rear
wheels and causes a rough or irregular cut.
DECK WHEEL ADJUSTMENT: The deck
wheels on all lawn and garden tractors should
be adjusted so they will be 1/2" to 1" off the
ground at all times. All cutting decks are float-
ing so that they can cut evenly over the
ground. The angle from front to rear is built into
the assembly on lawn tractors. Check to be
certain the distance from the bottom edge of
the deck to the ground is the same on both
sides of the deck. If it is not, adjust the links on
the left side of the unit. The linkage is adjust-
able on garden tractors. After you have leveled
the deck to the ground, you must adjust the
linkage up 1/2" to 1" above the ground.
Check to be certain the front of the deck is 1/4"
to 3/8" lower in the front of the deck than from
the rear of the deck. If it is not, adjust the two
front links to obtain this distance. This is of
most importance. You must keep in mind that if
the deck is riding on the ground and you want
to make a turn with the tractor the cutting deck
still wants to travel straight if the wheels are on
the ground and then as you turn, the cutting
deck will be dragged sideways. This then dam-
ages the wheels or the rollers.
The deck doesn't turn because there is no dif-
ferential on the rear axle assembly. This condi-
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CUTTING DECKS

CUTTING GRASS
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tion will also damage or bend the deck hangers
or deck links. From then on till the problems
are corrected the quality of cut is affected.
When the wheels are set to run on the ground,
the deck drive belt is also subjected to exces-
sive load conditions. This causes the belt to
become very tight and then loose repeatedly
during the course of mowing and again this
condition is magnified when making turns,
causing premature wearing on the belt. Bent or
uneven deck links can cause cutting problems.
Deck links should move freely and not bind
against the frame of the tractor or other com-
ponent parts.
CUTTING BLADES: First of all the blades
must be the correct part number for the mower
and original equipment style, according to the
owner's manual. The blade part number is
stamped and is found stamped into the back
side of the blade. MTD blades are tempered
and designed only to bend on impact and not
to break. They are tested for this properly and
upon impact with an object. Nothing can come
off the mower. The only time a blade breaks is
when first it is bent and the person operating
the mower chooses not to do anything about it.
With the blade now vibrating it will crack at the
mounting bolt holes. You may vision this as to
when you take a piece of metal and bend it
back and forth. Many times it will break in two
pieces. This condition on a mower blade can
easily be detected by looking at the crack. The
first part of the crack will be rusting and the
final stage of breaking will be shining and not
rusted.
The blade adapter will often also show evi-
dence as either being cracked or one of the
mounting ears bent upward. Blades are
designed to be high lift, therefore meaning that
they are made with a raised area, behind the
cutting tips which create a lifting action, pulling
the grass up to the blade. The proper lift is
more important to the cutting quality than even
a sharp edge. The blades must be run at full
throttle position on the mower. To assure this,
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