The coils don't fire together.
You can prove it by switching the primary wires.
RRR, RRR, Bam!
Now go pick up the vacuum caps off the floor.
Don't ask how I know.
A less exiting way to prove it is to imagine where one piston is when the other is at TDC (wasted spark not caring about compression vs. exhaust).
I ain't always good.
This of course begs the question of how does this work with a single piuckup coil.
The only answer I can come up with is there has to be some magic in the CDI.
It would have to discriminate between the short (90 degree) and long (270) intervals to get its bearings.
I also have a hunch that in some instances it may take a revolution or two to
lock on, and this may contribute to starting backfire/airbox explosions.
