Thermoquads are notorious for leaking fuel through cracks in the plastic body. Sounds like it's letting all the bowl fuel run into the engine. Try pulling the fuel line to the pump while idling, have a plug or pinch tool at the ready, and letting it totally run out of fuel. Hook it back up and walk away for a week. Start it up and see if it's better or different. It will take a little cranking to get the fuel back up to the carb. There are other problems besides cracks that can allow fuel to run out of the bowls while sitting. I just had a cracked body that was befuddling me. Carb worked great though.