Question on One Mag

[n38139]

If I install just one electronic ignition system should the remaining mag be an impulse or non-impulse or does it matter?

thanks

[tim2542]

**If** you want to be able to start the engine with the mag or even have it on when cranking, it will need to be an impulse. If its not an impulse mag steps need to be taken to prevent its use during cranking, else it rise up and smite thy ring gear.
Normally on certified stuff the non impulse mag is grounded thru the P lead and ignition switch during cranking and you are my attempting start up on one mag.
The issue is they are set to fire at 20-25 degrees and this much advance at low RPMs will cause the engine to attempt to turn backwards against the starter. The impulse gadget retards the spark and also once it snaps it spins the mag faster than it otherwise would be turning momentarily giving a stronger spark.
Tim

[Toobuilder]

I know the Pmag has a start retard function which allows much easier starts, so you want to start with the electronic anyway. This frees up the requirement to have that added mechanical complexity and weight of the impulse coupler (which are known to spontaneously disassemble themselves and trash the accessory drivetrain).

[N208ET]

I started with dual magnetos so had to have an impulse and put it in the left mag hole. When I bought my E-Mag, it made things even simplier yet for me. I used toggle switches for my P-Leads, so instead of having to keep the right mag off until after she started I now turn on everything where it stays until everything is turned off, made for one less thing to remember. And in the event the electronic ignition doesn't work, the impulse coupled mag will still fire her up.

Randy
8A

[n38139]

I have a 4381 which has a 5 or 2 degree lag I can't remember would that work?