Removing Mulch Insert; Installing Mulch Insert; Installing Grass Catcher; Blade Sharpening - Black & Decker MM850 Instruction Manual

mulched a second time to completely hide
the clippings. When doing a second cut,
mow across or perpendicular to the first
cut path. DO NOT MOW
PERPENDICULAR TO THE FIRST PATH
IF IT WOULD CAUSE MOWING
ACROSS A HILL.
Change your cutting pattern from week to
week. Mow north to south one week and
east to west the next week. This will help
prevent matting and graining of the lawn.
Removing Mulch
Insert
To remove the Mulch Insert so that you
can bag the grass, follow the steps listed
below.
1. Shut the mower off, wait until the blade
stops and unplug the mower.
2. Raise the rear discharge door and
hold it up as shown in Figure 6.
3. Locate your hand in the handle pocket
as shown in Figure 6, lift and pull out
the mulch insert completely.
4. The rear discharge door is spring
loaded. When you release it the door
will return to the closed position.
Installing Mulch
Insert
1. Repeat steps 1 and 2 for removing
mulch insert.
2. Slide the mulch insert into the
discharge opening until it is firmly in
contact with the deck.
Installing Grass
Catcher
1. Reaching down between the
lawnmower handles, raise the rear
discharge door to a vertical position
and hold the door up as shown in
Figure 8.
2. Pick up the grass catcher by the
handle and lower the grass catcher
between the lawnmower handles as
shown in Figure 8. Position the grass
catcher hanger hooks on the
lawnmower as shown in Figure 9.
Release the rear discharge door.
Warning: Never operate the mower
unless the hanger hooks on the grass
catcher are seated properly on the
lawnmower and the rear discharge door
rests firmly against the top of the grass
catcher.

Blade Sharpening

KEEP BLADE SHARP FOR BEST
MOWER PERFORMANCE. A DULL
BLADE DOES NOT CUT GRASS
EVENLY
WEAR PROPER EYE PROTECTION
FIG. 8
FIG. 9
HANGER HOOK
BLADE SHARPENING
Sharpening the blade twice during a
mowing season is usually sufficient under
normal circumstances. Sand causes the
blade to dull fast. If your lawn has sandy
soil, more frequent sharpenings are
required.
REPLACE BENT OR DAMAGED BLADE
IMMEDIATELY.
WHEN SHARPENING THE BLADE:
1. Make sure blade remains balanced.
2. Sharpen blade at the original cutting
angle.
3. Sharpen cutting edges on both ends of
blade, removing equal amounts of
material from both ends.
TO SHARPEN BLADE IN A VISE:
See Figure 10
1. Be sure the switch lever is released
and the blade has stopped and the
cord unplugged before removing the
blade.
2. Remove blade from mower. See
instructions for removing and attaching
blade.
3. Secure blade in a vise as shown in
figure 10.
4. Wear safety glasses and be careful
not to cut yourself.
5. Carefully file the cutting edges of the
blade with a fine tooth file or
sharpening stone.
7
6. Check balance of blade. See
instructions for blade balancing.
VISE
BLADE
SHARPEN THIS
EDGE ON
BOTH ENDS
OF BLADE
7. Replace blade on mower and tighten
securely.
BLADE BALANCING
Check balance of blade by placing centre
hole in blade over a nail or screwdriver
shank, clamped horizontally in a vise.
If either end of the blade rotates
downward, file that end. Blade is
properly balanced when neither end
drops. (Fig. 11)
FIG. 11
Removing and
Attaching Blades
1. RELEASE SWITCH LEVER TO TURN
MOWER OFF, WAIT FOR THE
BLADE TO STOP, AND UNPLUG
MOWER!
2. Cut a piece of 2x4 wood (about 2 feet
long) to keep blade from turning while
removing blade nut.
3. Wear gloves. Position wood and
remove nut as shown in Figure 12.
FIG. 12
FIG. 10
FINE
TOOTH
FILE