Darn Coil again (I think)

Yesterday, I was mowing when I ran out of gas. So I refilled the tank and tried starting it. (Briggs opposed twin 19.5hp) It wouldn't start. So I got the starter fluid out, and that didn't work. So, I pulled the plug, placed it on the edge of the exhaust and noticed it wasn't sparking. So I let it set for an hour or so, and tried it again. If fired right up and did fine until I got to a bumpy part of the yard. I noticed it was trying to quit on me. With every bump, it would stall just a little. Until finally it stopped and wouldn't start again. And like before, no spark.



So, I put on another magneto, and that didn't solve the problem either. I disconnected the kill wire, and still no spark. I've got it on right side up. I've got it gapped just right (new business card).. So, I don't know what the hecks going on.



BTW, I placed the wrench on the magnets, and they seem to be good. My wrench stuck to it as normal...



With the kill switch detached, seems the ONLY thing that it could be would be both magneto's are bad. But considering that they're both new (within a couple of months and only a few hours on the one I removed) I'd say the chances of them being bad are very slim. Is there anything else? Something I'm missing? I've had this problem before, but that was because I'd installed the magneto upside down.