Dumb question but does your carb insulator and gasket have the grooves that expose the tiny holes in the bottom of the carb?
I had 2 different gaskets and the notches are in different places. Blocking those holes might not cause the issue you are having but the carb will act funny if both are covered.
Each different gasket I had covered a different hole. I matched the gasket to the insulator and got much better results.
Just a thought
Good luck
Rich
