I have an older Cub Cadet Z-Force zero turn mower, model # 17AF3AGV010. I just put in a new starter and it started right up, problem is, every time I disengage the brake the engine shuts downs, put the brake back on and the engine starts back up again. It'll run on idle without a problem, as soon as I release the brake it dies. It ran fine before I put the new starter in, any ideas where to start troubleshooting?