Jekyll and Hyde engine frustration

[Pighead]

It feels like it’s just not getting enough fuel but I could be wrong about that.

Have we ruled out fuel delivery problem 100% ? Should be easy enough to just watch the porthole window in the carb as the engine dies...

 

[Gotta40]

hows your valve adjustment? mine was acting goofy and I rechecked and had one or two a little tight. seemed to fix it.

 

[anothernz45]

20 mins is a long time for an ignition issue to show up - not an issue with the gas tank vent?

 

[charliemeyer007]

I think it could be either electrical or fuel. Circuits can do strange things with heat. Chips fail with electron drag eroding metal away at a choke point or the thermal cycle causes a crack in the conductor. Crap in the fuel can block the port due to fuel flow, then release when the vacuum stops.

 

[Slow Poke]

Over the weekend I was able to get back to this problem and I believe it’s resolved. The valves were adjusted warm early on in the process but definitely a good thought. I thought it could be a Vapor lock situation and went so far as to replace the tank but it didn’t help. Also a good thought though. The carburetor was where I started and even went through it twice without success.
In the end It turned out to be a bad distributor. What part of it went bad I don’t know but when I replaced it everything improved immediately. I’ve driven it several times now gradually increasing the distance from home and now feel confident to drive it whenever and wherever. The new distributor is a points distributor that I bought from City Racer. It’s an OEM distributor that wasn’t used in the US. It’s for desmogged applications so it worked great for me. Thanks for all of the helpful diagnostic advice. I sincerely appreciate it