The Cub Cadet RZT 50 Zero Turn mower has the advantage of cutting difficult lawns because of its maneuverability. However, the RZT 50 can't cut one blade of grass if it doesn't start. While starting problems can arise from the engine, there are other safety and ignition issues that should be considered if your RZT 50 won't start.
Safety Interlock System
The Cub Cadet RZT 50 has a Safety Interlock System that's designed to prevent a start if the mower is not in a safe position. The Safety Interlock System requires the left- and right-hand drive control levers to be pushed fully outward into the neutral position. The PTO, which controls the mowing blade, must be in the "disengaged," or off, position. The RZT 50 also won't start if the operator isn't in the operating seat. If the parking break is not engaged and the operator leaves the seat, the RZT mower will stop.
The RZT will not start if the dashboard controls are not in the proper configuration before the ignition switch is turned to start. The parking break must be engaged. The throttle control must be between the "slow" and "fast" positions. If the engine isn't already warmed up, the choke control has to be pulled all the way up to the full choke position.
An empty or near-empty fuel tank won't provide enough fuel for combustion, thus preventing an engine start. If the RZT 50 is on a slope, fuel might be toward the back of the tank, which won't reach the carburetor primer line when starting. Also ensure that fuel is no more than 30 days old. Otherwise, old fuel will begin to break down and introduce sediments that clog the fuel system.
Dead batteries also can prevent an RZT 50 from starting. Test the battery to see if it has a full charge. Consult the battery owner's manual to determine its longevity; they can lose the capacity to maintain a charge over time. If the battery is testing full but there are still starting problems, check the battery terminals for corrosion. Clean them with a stiff wire brush and baking soda. Also, check the battery leads for any damage or if they are in the wrong position. The red lead should be on the positive terminal, as indicated with a "+" sign, while the black negative lead should be on the negative terminal.