Use and Care Manual
LAWN MOWER BLADE
AC04020/AC04021/AC04145
For use with RYOBI® 40 Volt
20 in. Lawn Mower ONLY
991000488
2-3-17 (REV:03)
WARNING!
To reduce the risk of injury, user
must read and understand the
operator’s manual for their lawn
mower and this instruction sheet.
Always wear eye protection with
side shields marked to comply with
ANSI Z87.1. Ensure compatibility
and fit before using this accessory.
Do not use this accessory if a part
is damaged or missing. If you are
not comfortable performing any of
the functions described in these
instructions, take your unit to a
qualified service center.
WARNING:
Always protect hands by wearing
heavy gloves and/or wrapping the
cutting edges of the blade with rags
and other material when performing
blade maintenance. Contact with
the blade could result in serious
personal injury.
REPLACING THE CUTTING
BLADE
See Figures 1 - 2.
Stop the motor and remove the
fuse key. Allow blade to come to a
complete stop.
Remove the battery pack.
Turn the mower on its side.
Wedge a block of wood between
the blade and mower deck to pre-
vent the blade from turning.
Loosen the blade nut by turning it
counterclockwise (as viewed from
bottom of mower) using a 15 mm
wrench or socket (not provided).
Remove the blade nut, spacer, blade
insulator, and blade.
Make certain the blade carrier is
pushed completely against the mo-
tor shaft.
Fig. 1
Place the new blade on the shaft
against the blade carrier. Ensure
blade is properly seated with shaft
going through center blade hole and
the two blade posts inserted into
their respective holes on the blade.
Make sure it is installed with the
curved ends pointing up toward the
mower deck and not down toward
the ground. When seated properly,
the blade should be flat against the
blade carrier.
Replace the blade insulator and
spacer, then thread the blade nut
on the shaft and finger tighten.
NOTE: Make certain all parts are
replaced in the exact order in which
they were removed.
Torque the blade nut down
clockwise using a torque wrench
(not provided) to ensure the bolt
is properly tightened. The recom-
mended torque for the blade nut is
350-400 in. lbs.
A - Blade (lame, hoja)
B - Wrench (clé, llave)
C - Block of wood (pièce de bois, bloque de
madera)
A
B
C
Fig. 2
A - Blade carrier (support de la lame, soporte
de la hoja)
B - Shaft (arbre, eje)
C - Blade (lame, hoja)
D - Blade insulator (isolant de lame, aislante
de hoja)
E - Spacer (entretoise, separador)
F - Blade nut (écrou de lame, tuerca de la
hoja)
G - Blade posts (tiges pour lame, montantes
de cuchilla)
G
G
F
E
C
D
A
B
B
G
G
CALIFORNIA
PROPOSITION 65
WARNING:
This product and substances that
may become airborne from its use
may contain chemicals, including
lead, known to the State of Califor-
nia to cause cancer, birth defects,
or other reproductive harm. Wash
hands after handling.
TECHTRONIC INDUSTRIES POWER EQUIPMENT
1428 Pearman Dairy Road
Anderson, SC 29625 USA
1-800-860-4050
www.ryobitools.com
NOTE: For purposes of the illustrations in this manual, only standard replacement blades are shown. However, bagging
blades would install in the same way.