question

couldnt you program a PIC chip to advance and retard the timing for high and low RPM's? maybe based on a pulse timing from the hall effect sensor. seems like that would be a great way to vary the timing.

it looks to me, and im not an electrical engineer YET, but all this is a cap gets charged and discharged via a transistor with a hall sensor that does the triggering. if you are using it on engines like the ryobi even CH says you dont need to change the timing at different RPM's.