I think I just found a problem on a magneto coil ring, I was looking for since a few months.
I tried about everything that was on this forum about the magneto but always after a few days the problem was back and I decided to take the engine out and rebuild the coil ring.

This is what I found:
While I was watching the photos I took, I saw a small carbon trace on the insulating paper under the coil ring terminal. With a small screw driver I could push the terminal against the magneto core and short out the magneto.
This is maybe what happened with the spring loaded needle of the terminal on the hog head.

Just for what its worth.

Andre
Belgium

That lead blob looks much larger than most. Could it be a little too big, to where it overlaps the core? Maybe just trim it back?

Jerry,
This was also what I was thinking but the screw is not tied and move in its hole. I will take the coil ring out and rebuild the terminal.

Andre
Belgium

I've seen where pressure on the terminal caused the terminal to short onto the rivet that holds the terminal insulator. Without the pressure, everything seemed OK. Very insidious.