Re: I had a breakdown today...
The blue and white mag windings, while wound separately in relation to each other, have a common ground that is soldered to the mag frame.
The black wire also grounds to the frame via a seperate eyelet soldered to it's end which is captured under one of the mag mounting screws.
If you are getting continuity between the black wire end and everywhere on the engine including the mag frame then that indicates that the eyelet connection is good.
It seems to me that the common ground for the windings that is soldered to the mag frame has failed.
"It's a chinagirl. It's a sometimes fun little engine that often will break your heart. It's disposable.
Does not come with a fortune cookie."