Yard Machines 520 Lawn Mower User Manual


 
14
Transmission
The transmission is pre-lubricated and sealed at the
factory. It does not require checking. If
disassembled for any reason, fill with 2 ounces of
Alvania grease, part number 737-0168.
WARNING: Be sure to disconnect and
ground the spark plug wire before
performing any repairs or maintenance.
NOTE: When tipping the unit, empty the fuel
tank and keep engine spark plug side up.
CUTTING BLADE
WARNING:
Periodically inspect the
blade adapter for cracks, especially if you
strike a foreign object. Replace when
necessary.
When removing the cutting blade for sharpening or
replacement, protect hands by using heavy gloves
or a rag to grasp the cutting blade.
Remove the bolt and bell washer which hold the
blade and adapter to the engine crankshaft.
Remove the blade and adapter from the crankshaft.
Sharpening Blade:
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. We recommend
using the Arnold blade balancer (part # SBB-102)
available at your local dealer.
If the blade is not balanced, remove metal from the
heavy side until it balances evenly. We recommend
that the blade be always removed from the adapter
for the best test of balance.
Before reassembling the blade and the blade
adapter to the unit, lubricate the engine crankshaft
and the inner surface of the blade adapter with light
oil (or engine oil). Also lubricate the bolt holes, bolts
and inner surface of the nuts.
Replacing Blade
NOTE:
If the adapter is keyed, make sure that the
key in the adapter is aligned with the key slot on the
crankshaft.
1. Place the two pulleys, the flat washer, the
spring washer and the spacer on the engine
crankshaft. See Figure 14.
Figure 14
2. Install the blade adapter on the crankshaft with
the “star” away from the engine. See Figure 15.
Figure 15
3. Place the blade with the side marked bottom (or
with part number) facing away from the adapter.
4. Place the blade bell support over the blade
aligning the tabs in the holes of the blade with
the hole in the bell support and insert the hex
bolt through the blade assembly. Refer to
Figure 15 for the correct order of assembly.
5. Tighten the hex bolt according to the blade
mounting torque mentioned below.
Blade Adapter
Spacer
Spring
Washer
Flat
Washer
Pulley
Halves
Blade Adapter
Blade Bell
Support
Hex Bolt