I have a new-ish tank so no trash to the carb.
Timing was my next thought , but it ran so well for so long and nothing was touched.
I have a glas fuel filter just before the carb so I can see it is being fed a continuous supply. Although this is my theory as it seems to run till the bowl is empty then die except it starts right back up without priming the carb.
The carb is a new factory rebuild and it runs the same with the new carb as it does with the old.
coil and condensor were a fleeting thought since she fires right back up. after she dies