On a side note, after separating the coil leads, it took a much leaner mixture to get it to run smooth.  Before, the best it would idle was about 1200rpm, now it will idle nicely at 900 rpm, not that I want to do that, but it shows that the improvement isn't all in my head.
   
   

What sort of mechanism fires the coils? A regular Kettering system with an SCR? A field collapse will generate very high voltages in the primary circuit if no protection is built in. (like the capaciter in the old points system).

Many restrikes may occur after the planned firing, and at speed, low secondary voltage from poor rise time may develop. False triggering and an induced 180 degrees out of faze preignition are possible. Just one event is too many. All wires are antenna. All secondary wires radiate RF unless they are shielded, and the shielding is grounded.

 

I destroyed a factory Racing Pport learning this. You can see it all on an old "O" scope.

 

Lynn E. Hanover