Glenn thinks it's the mags.

At first, we thought the Hisso was going to start. But it didn't. It would run, but only as long as the prime lasted. Both Glenn and John Cournoyer thought the only way to really tell was to put the mags on a test bench and see if they are firing under compression.

Glenn doesn't have a test bench, so he improvised using his lathe and a homemade spark indicator. The mags, at low (starting) produced 0, no, none spark. Neither one of them. Looks like the booster mag is causing the spark for the start and the mags are not picking up when they are supposed to. At fast idle rpm (bottom) the mags are producing sparks to fire the engine.

Now, how to fix it? Haven't read that chapter yet, I'll keep you informed.