MTD 609 Operator's Manual page 20

Cutting Blades
WARNING:
Be sure to shut the engine off,
remove ignition key, disconnect the spark
plug wire(s) and ground against the engine to
prevent unintended starting before removing
the cutting blade(s) for sharpening or
replacement. Protect your hands by using
heavy gloves or a rag to grasp the cutting
blade.
A
WARNING: Periodically inspect the blade
adapter and/or spindlefor cracks or damage,
especially if you strike a foreign object.
Replace immediately if damaged.
The blades may be removed as follows.
Remove the deck from beneath the tractor, (refer to
CuttingDeck Removalon page 19) then gently flip the
deck over to expose its underside.
Place a block of wood between the center deck
housing baffle and the cutting blade to act as a
stabilizer. See Figure 15.
Hex Flange Nut
/
Spindle Assembly
Figure 15
Use a 15/16" wrench to remove the hex flange nut
that secures the blade to the spindle assembly. See
Figure 15.
To properly sharpen the cutting blades, remove equal
amounts of metal from both ends of the blades along
the cutting edges, parallel to the trailing edge, at a 25 °
to 30 ° angle. See Figure 16.
IMPORTANT: If the cutting edge of the blade has already
been sharpened to within 5/8" of the wind wing radius,
or if any metal separation is present, replace the blades
with new ones. See Figure 16.
Blade Separation
/
Worn Blade Edge
Wind Wing
__ rnia#.u m
Sharpen Edge Evenly
Figure 16
It is important that each cutting blade edge be ground
equally to maintain proper blade balance.
A poorly balanced blade will cause excessive vibration
and may cause damage to the tractor and result in
personal injury.
The blade can be tested by balancing it on a round
shaft screwdriver. Grind metal from the heavy side until
it balances evenly.
When replacing the blade, be sure to install the blade
with the side of the blade marked "Bottom" (or with a
part number stamped in it) facing the ground when the
mower is in the operating position.
IMPORTANT: Use a torque wrench to tighten the blade
spindle hex flange nut to between 70 foot-pounds and
90 foot-pounds.
Fuses
Two fuses are installed in your tractor's wiring hamess
to protect the tractor's electrical system from damage
caused by excessive amperage.
If the electrical system does not function, or your
tractor's engine will not crank, first check to be certain
that the fuse has not blown.
One can be found under the hood mounted behind the
top of the dash panel on the support bar.
The other can be found under the seat mounted to the
inside of the tractor frame next to the battery tray. Pull
the fuse out and inspect it to determine if it is good or
blown.
WARNING: Always use a fuse with the
same amperage capacity for replacement.
2O