I'll try revving it in Neutral when I get home and see what happens. I'm sure the neighbors will be pleased.
From what I've been reading, it does sound like the coils. I guess if they overheat they cut out, which in theory should happen if I'm revving it in Neutral, but why I was several miles down the road when it happened before they got too hot and crapped out.
I wondered if it was similar to yours Stephen. Your post was the first thing that came to mind on the side of the road.

If I hadn't noticed the tach, I would have never thought about it being electrical.