hey guys i've got an older bobcat zt219 with a 19 hp kawasaki fh601v (350 hrs. on whole machine). started "acting up" today. first i noticed when throttling down there was a SLIGHT back fire. a couple hours later, it began to run on 1 cylinder. stopped... pulled the plug and i verified NO spark on one side. crazy thing is, started it up to load on the trailer and within a second or two the "dead side" kicked in and both cylinders were firing again. i returned to cutting however it did happen a few more times, throughout the day. any idea what is going on? i've never had to do anything to these engines, other than basic maintenance. haven't pulled the shroud, yet... what might cause 1 side to have spark and the other nothing... coil? regualtor? moreover, why would the "questionable" side work intermittently? i always thought if a coil, reg., etc. failed, it would fail completely. hoping one of you experts have run into a similar problem and/or can help me out here. thanks, looking forward to hearing your answers. have a good one.