My 78' with a new weber does the same, I have a new fuel pump to try but I doubt it will help. It starts better with the choke on these days. I have fuel filter just before the carb it fills slowly when starting it up.
Hi knowledgable folk, just trying to find out / gather ideas why my Series 3 2.25 fuel drains back so quick from the carb (Weber). Starts great in the morning from cold and if you leave it for 10-15 minutes when hot it'll start straight away...