Exmark COMMERCIAL 21 Operator's Manual page 36

Troubleshooting
Problem
Lawn mower does not self-propel.
(Self-Propel Units Only)
Difficult to pull lawnmower rearward
(Self-Propelled Units Only).
Possible Cause
1. The self-propel drive cable is out of
adjustment or is damaged.
2. There is debris under the belt cover.
1. Transmission is locked.
36
Corrective Action
1. Adjust the self-propel drive cable. Replace
the cable if necessary.
2. Clean the debris from under the belt
cover.
1. Push mower forward to disengage the
transmission and then pull rearward.