Yard-Man 970 Series Owner's Manual page 18

CUTTING BLADE REMOVAL, REPLA _EMENT AND SHARPENING
Blade
Adapter ""
Blade Bell
Support
Figure 13
• When removing the cutting blade for Sh_Lrpening or replacement, protect hands with heavy gloves or a rag
before grabbing the blade.
• Remove the bolt and blade bell support \ zhich hold the blade and adapter to the engine crankshaft.
• Remove the blade and adapter from the _rankshaft.
_, WARNING:
Periodically inspect th_ blade adapter for cracks, especially if you strike a foreign object.
Replace when necessary,
When sharpening the blade, follow the origin _1angle of grind as a guide. It is extremely important that each
cutting edge receives an equal amount of gri _ding to prevent an unbalanced blade. An unbalanced blade will
cause excessive vibration when rotating at hig 1 speeds. It may cause damage to the mower, and it could break
causing personal injury.
The blade can be tested by balancing it on a r_und shaft screwdriver. Remove metal from the heavy side until it
balances evenly. It is recommended that the bade always be removed from the adapter for the when testing for
balance,
Before reinstalling the blade and the blade aJapter to the unit, lubricate the engine crankshaft and the inner
surface of the blade adapter with light oil.
• Be sure to install the blade with the site of the blade marked "Bottom" (or with part number) facing the
ground when the mower is in the operatil _gposition.
• Slide blade adapter onto engine cranksh #t.
• Place blade on adapter, Be certain the L lade is aligned with and seated onto the blade adapter flanges.
• Place blade bell support on blade. Mak ; sure the notches on the blade bell support are aligned with the
small holes in the blade.
• Replace hex bolt.
• Tighten hex bolt to torque: 450 in. Ibs. n'in., 600 in. Ibs, max.
NOTE:
To ensure safe operation of your unit, the blade bolt must be checked periodically for correct torque.
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