I am having issues with the engine stalling when turning the deck on or applying pressure on the hydrostat pedal going forward or reverse. It does not do this all the time but will do it and mow. I can rev up the engine and raise the hydraulic deck up and this will not affect it. It has a 25 hp Kohler. What could be causing this? If it is electrical....what is it? If it is a safety switch...Where is it? If it is fuel...Where? Help???