Morgans wrote:



Both of those spark vibrators just make a constant sparking, just waiting
for the right combination of fuel, air and compression, don't they?

If that is the case, it would seem like that would be like a very advanced
spark, and could easily make a backfire to spin the engine backwards. Is
this what you have observed?

If that is not how they work, then...
Never Mind ! ! ! g

The system produces a much higher powered, rapid succession of sparks,
but they are only delivered to each plug via a second set of points in
the mag, that are set at a delayed timing period.

Happy Flying!
Scott Skylane