I'm not convinced it is an electrics problem. If it were then it would
most likely stop running once hot.

First the obvious - I trust you aren't putting choke on when restarting
it while hot?

Next, check the tuning - should be 1 and 1.

Next, how is the compression?. It is hard to describe what to look for
- you sort of know through experience. When pulling the engine over
slowly you should be able to feel the compression resisting the pull.
It should be reasonably strong. Try this both hot and cold.

Try that and let us know how you get on. If this doesn't work then are
there any other symptoms? Does it idle ok? What is it - a chainsaw? You
mention stalling - is this through bad use or does it just stall
itself?

Alan.