Murray 20-inch - Manual (Page 18)

MAINTENANCE
18
F–040406L
BLADE SERVICE
WARNING: Before you inspect
the blade or the blade adapter,
disconnect the wire to the spark
plug. If the blade hits an object,
stop the engine. Disconnect the
wire to the spark plug. Check the
unit for damage.
Frequently check the blade for wear or dam-
age such as cracks. Frequently check the bolt
that holds the blade. Keep the bolt tight. If the
blade hits an object, stop the engine. Discon-
nect the wire to the spark plug. Check the
blade adapter for damage. Check for a bent or
damaged blade, a badly worn blade, or other
damage. Before you operate the unit, dam-
aged parts must be replaced with factory re-
placement parts. For safety, replace the blade
every two years. Keep a sharp edge on the
blade. A blade that is not sharp will cause the
ends of the grass to become brown. Remove
the blade as follows.
HOW TO REMOVE THE BLADE
WARNING: Before you remove
the blade, disconnect the wire to
the spark plug. The blade has
sharp edges. When you hold the
blade, use gloves or cloth materi-
al to protect your hands.
1. Drain the fuel tank.
2. Lift the side of the mower that has the
muffler or spark plug.
3. Use a piece of wood to keep the blade
from rotating.
4. Remove the bolt that holds the blade.
5. Check the blade according to the ”Blade
Service” instructions. Replace a badly
worn or damaged blade with a factory re-
placement blade.
6. Mount the blade with the curved edges to-
ward the housing. If the blade is upside
down, the blade will not cut correctly and
can cause an accident.
7. Fasten the blade with the original wash-
ers and bolt. Make sure the outside rims
of the Belleville washers are toward the
blade (Figure 13).
8. Tighten the bolt that holds the blade to a
torque of 30 foot pounds.
WARNING: Always keep the bolt
that holds the blade tight. A loose
bolt or blade can cause an acci-
dent.
Blade Adapter
Blade
Belleville
Washer
Washer
Bolt
Figure 13
ПППППП
ММММ
ММММ
ПП
ПП
ПП
ММ ММПП ПП
С
Belleville Washer
Mulching Blade
Bolt
Blade Adapter
Flat Washer
HOW TO SHARPEN THE BLADE
WARNING: Vibration is the result
if the blade is not correctly bal-
anced. A blade that is damaged
with cracks can break and cause
an accident.
1. Sharpen the blade two times a year or ev-
ery 25 hours.
2. If the blade is on the unit, do not sharpen.
Remove the blade according to the in-
structions in ”How To Remove The Blade”.
3. Clean the blade with a brush, soap, and
water. Check the blade. Look for cracks,
nicks, or other damage. Replace a blade
that is badly worn, bent, or damaged with
a factory replacement blade.
4. Sharpen the blade with a file. Make sure
you keep the original beveled cutting edge
(Figure 14).
(Continued following page)