The ones who never made it back

It could be your coil overheating. After cooling down for a couple of hours, all was fine again; I had this exact issue last year, fixed thanks to the excellent knowledge of TLB Try swapping out the coil for a known good one. Easy fix if this is the issue

 

Can you recommend a good coil?

 

What’s your location. Maybe someone has a good second hand one.

 

I'm in Hampshire but I think after 10 fairly trouble free years it's probably time to open up my wallet !!

 

This one will probably be as good as any. https://www.heritagepartscentre.com/uk/043905115c-ignition-coil-12-volt.html

 

I had (still got somewhere) a pertronix oil filled (aren’t they all?) coil and electronic ignition that never let me down. Sadly, the newer ones aren’t so great or maybe a bit hit & miss.

 

Part swap bingo?
You don't know there's anything wrong with the coil, I'd try and borrow one

 

Oh dear