Yard Machines 570 - Manual (Page 17)

17
To Remove Blade
• Remove the bolt and blade bell support which hold the blade and adapter to the engine crankshaft. See
Figure 15A.
• Remove the blade and adapter from the crankshaft.
To Replace Blade:
• Before reinstalling the blade and the blade adapter to the unit, lubricate the engine crankshaft and the inner
surface of the blade adapter with light oil.
• Install the blade adapter on the crankshaft with the “star” away from the engine. See Figure 15A.
FIGURE 15
• Place the new blade with the side marked bottom (or with part number) facing away from the adapter.
• Place the bell support next. Make sure to align the tabs in the holes of the blade with the hole in the bell
support.
• Insert the hex bolt through the blade assembly. See Figure 15A for assembly.
• Use block of wood to hold blade again while you tighten the bolt clockwise. Follow the recommended
torque for the bolt which is 450-600 in.-lbs.
IMPORTANT: The bolt, used to secure the blade to the engine, is specially heat-treated. Do not substitute. To order
replacement bolt, refer to the Parts List section of this manual.
WARNING: To ensure safe operation of your unit, all nuts and bolts must be checked periodically for
correct tightness.
To Sharpen Blade:
• The blade can be sharpened with a file or on a grinding wheel. Do not attempt to sharpen while operator is
on the mower.
• Follow the original angle of grind as a guide. Make sure that each cutting edge receives an equal amount of
grinding to prevent an unbalanced blade.
NOTE: An unbalanced blade will cause excessive vibration when rotating at high speeds, may cause damage to the
mower and could break, causing personal injury. Test the blade by balancing it on a round shaft screwdriver or a
blade balancer. See Figure 15B. If the blade is not balanced, remove metal from the heavy side until it balances
evenly.
Replacing Rear Flap
The rear flap is attached to the rear of the mower deck, and is designed to minimize the possibility of objects being
thrown from the rear of the mower towards the operator. If the rear flap is damaged in any way, replace as follows:
• To remove the old flap, compress the hinge clips and remove from the slots on the deck. Place new spring
clips in the slots on the new flap. Compress the spring clips and reinsert flap in slots on deck.
Adjusting Cutting Height
Your mower is designed to operate at three settings of cutting height. Make sure to disconnect the spark plug wire
before starting the adjustment job. To change the cutting height, proceed as follows:
Blade
Blade Bell
Support
Hex Bolt
Blade
Crankshaft
1. Insert screw driver through hole
2. Blade should be parallel to ground
Screw
Driver
Ground
Blade
A B
Adapter
(Torque: 450 - 600 in.-lbs.)