I can't see how a CDI will kill a magneto.never had a bad mag until this particular engine, I know one thing, a bad cdi will fry the mag,
it was running fine with the newest mag, I decided to hook up a cdi I had that was suspect and well..... yep it was bad and it also killed the mag,
I thunk I just had a bad experience since the bad cdi is what killed the first mag, I put a very old and oily mag from a junk engine in it and it lasted a few rides, I put newest one in andit was running fine until I hooked up the same cdi that killed the first mag so I think once I get a new mag in and get it done up good it should be good to go for a long time.
All it can do is short and that's how I kill motors, short the magneto output.
You using 3 wire mags or 2 wire?