That carb has a tube cast in the air horn across the top of the carb. On one end of the tube is a tiny core plug. Occasionally that plug falls out or is blown out when cleaning the carb with compressed air. That will cause a massive vacuum leak with symptoms you describe.
It can be filled with e-poxy glue or similar.
George
Last edited by Wrenchbender Ret.; 11/19/2024 4:33 PM.
