Grasshopper mowers are among the industry's first zero-turn lawn mowers. Zero-turn mowers can turn on a dime by using two separate drive systems. Each wheel has its own pump and drive motor, while sharing the same hydraulic fluid reservoir. If the lawn mower does not start or you need to push it, you have to disengage both hydraulic pumps so that the mower can freewheel. It's a simple procedure that takes only a few minutes.
Set the parking brake on your Grasshopper lawn mower.
Raise the seat to expose the two hydraulic pumps located over each of the wheels. There are hex-head bolts on the side of each pump, and on some models there is a tiny hole to fit a small screwdriver.
Loosen the bolts on the side of the each pump by turning them counterclockwise, using either a wrench or a screwdriver. Do not remove the bolts completely.
Disengage the parking brake. You can now freewheel your Grasshopper mower.