Craftsman 247.370480 Operator's Manual page 14

bLADE CARE
WARNING
When removing the cutting blade for sharpening or replacement,
protect your hands with a pair of heavy gloves or use a heavy rag to
hold the blade. Be certain to stop motor and remove key.
Periodically inspect the blade adapter for cracks, especially if you
strike a foreign object. Replace when necessary. Follow the steps
below for blade service.
blade Removal
1. Stop the motor and remove ignition key. Turn the mower on its
side.
2. Place a 2x4 block of wood approximately 8.5" long between the
deck housing and the cutting blade to act as a stabilizer. See
Figure 12.
Block of Locking
Wood Plate
3. Loosen and remove the blade bolt, locking plate, and blade. See
Figure 12.
SERVICE AND MAINTENANCE
Blade
Blade
Bolt
Figure 12
blade Sharpening
IMPORTANT: If any metal separation is present, replace the blades
with new ones.
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 13.
NOTE: 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 mower 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.
An unbalanced blade will cause excessive vibration when rotating
at high speeds. It may cause damage to mower and could break
causing personal injury.
blade Installation
1. Place the cutting blade, locking plate, and blade bolt on the motor
shaft and thread the blade bolt in finger tight.
NOTE: Make certain to replace the parts in the exact order in which
they were removed. When installing the cutting blade, be sure it is
installed with the curved ends pointing towards the mower deck and
not towards the ground.
2. Torque the blade bolt down using a torque wrench to assure the
bolt is tightened properly. The recommended torque for the blade
bolt is 170-220 in. lbs.
To ensure safe operation of your mower, periodically check the blade
bolt for correct torque.
The blade hardware is not only used to attach the blade assembly,
but is also an insulated safety device and should never be altered in
any way. If replacement is necessary, use original equipment parts as
shown in the parts list.
14
Figure 13
WARNING
WARNING