Need help with my Holley

Holley's are VERY sensitive to debris, but it's been a long time since I got something in the needle & seat. Difficulty to keep it running to it overflowing seems to depend on the size of the "junk" in the needle & seat. If it's something that happens suddenly, that's the first place to look. Periodically, when I have the carb apart, I spray carb cleaner through every hole & passage in the carb as preventive maintenance. (Watch your eyes.) A bad/ruptured power valve can also cause running issues but not to overflow.