I'm flustered with this one. It is on a Scag Turf Tiger and won't start. No spark. It started coming and going a while back. It would die or start to die and sometimes come right back. Right now there is no spark on either cylinder. It seems improbable that both coils went out together and come back together. I was probing around on it with a meter the other day and it came back and about knocked me on my keester. Started twice, then went away the next morning. I have replaced the ignitor, both plugs, ohmed out the pulser coils. When I ohm out the ignition coils, the secondary measures 18K ohms. My book says 15K ohm is the top of the range but the book I have also lists the wrong plug so I don't trust it fully. I have jumpered across the relay and that didn't help. I have looked extensively at the grounding and it looks ok. I have two new coils on order but I really doubt that is what the problem is since whatever it is comes and goes to both coils at the same time. Any suggestions? I'm all ears.