Exmark COMMERCIAL 21 Operator's Manual page 17

Figure 10
1. Blade control lock lever
2. Locked position
3. Blade control bail
3. Squeeze the blade control bail against the handle
and release the blade control lock lever; the blade
should engage.
4. Release the blade control bail to disengage the
blade. The blade control lock lever will reset to
lock the blade control bail.
Using the Mulch Plug
Occasionally you may wish to use the mulch plug to
mulch the grass and leaf clippings back into the lawn.
• Installing the Mulch Plug:
1. Stop the engine and wait for all moving parts
to stop.
2. Remove the grass bag if it is on the mower.
3. Raise the discharge door and insert the mulch
plug into the discharge opening. The lip on
the plug will snap into the mower housing.
4. Push forward
5. Unlocked position
6. Squeeze against handle
1. Mulch plug
2. Discharge door
4. Lower the discharge door.
• Removing the Mulch Plug:
Note: When grass is thick and lush, clippings
may collect on and around the discharge tunnel
plug. This may make it difficult to remove the
plug. Clean the plug thoroughly after each use.
1. To remove the mulch plug, raise the discharge
door and pull the mulch plug out of the
discharge tunnel.
2. Lower the discharge door.
Checking the Blade Brake Clutch
(Blade Brake Clutch Units Only)
Check the Blade Brake Clutch (BBC) system before
each use to ensure that it is operating properly.
Normal Test:
1. Stop the engine and wait for all moving parts to
stop.
2. Move the lawn mower onto a paved surface in
a non-windy area.
3. Set all four wheels to the 2 1/2 inches (6.4 cm)
cutting height (see Figure 13 and Figure 14)
4. Take a half sheet of newspaper and crumple
it into ball small enough to go under the deck
(about 3 inches or 7.6 cm in diameter) as shown
in Figure 12.
17
Operation
Figure 11
3. Lip
4. Mower housing