Fuel Line Rerouting
How are you priming the carb?
what is the idle RPM set to?
have you replaced the fuel cap lately?
THOUGHT...
when you had a leak how did you fix it? New hose? maybe some of the old hose scraped off into the fuel line to the carb and is blocking the inlet port? I have seen some carbs that have a small screen in the fuel inlet port ( motorcraft IIRC) perhaps your does too???