Toro 20999 Manuel D'instructions page 7

For the switch to detect the presence of the mulch plug, the
top of the mulch plug lever must lie fully in the bottom
of the channel (Figure 7).
1. Top of mulch plug lever in channel bottom
1. Insert the mulch plug into the machine if it isn't already
installed (Figure 8).
2. Squeeze the button on the lever with your thumb, and
fully insert the mulch plug into the opening (Figure 9).
Figure 7
Figure 8
3. Release the button on the lever and ensure that the top
of the lever lies fully in the switch channel (Figure 10).
If the top of the lever is not in the switch channel,
your machine will not start.
Note: If the lever does not latch properly, disconnect
the wire from the spark plug and check for and remove
any debris buildup in the tunnel.
7
Figure 9
Figure 10