Brokenhead is correct, imho. Pull the carb and rebuild with a new kit. You may not even see the trash that is in there, but a good cleaning and resetting floats is very important. Anything else and you are chasing ghosts. I had similar problems, and was finally cured when the carb was clean and reset and the fuel was filtered so no more trash could get in.
Let us know.

1951 Chevy 3100
Some days you get the bear. Some days the bear gets you.