as I posted in the thread, it’s a 2011 x500. The serial # is 1MOX500ACBM0162144. It has the 24 hp Kawasaki E/NO FS730VA10365. After replacing the plugs and the coils it is better. however twice since, after I mowed for a half hour or so each time, it has stalled out, and then I turned the key off. Then a second later, the engine backfired. Then it would start right back up and not bother again