Cub Cadet - Backfire problem.
I have a cub Cadet model 2146 with a 14 HP Onan engine model ZX390 11317D. The engine runs fine except it backfires eight out of ten times when the key is turned off. This happens regardless of throttle RPM speed. There is also a 10 second spark knock prior to the backfire. What may be the problem or a solution?
Thanks to all.