Here's tip:
spray carb-cleaners DO NOT WORK
With removal of chlorinated compounds (carbon-tetrachloride and tri-chloroethylene), "carb-cleaners" are just useless weak solvents with no cutting action.
You need to completely disassemble carbs down to constituent components:
Then clean every component by physical scrubbing with acetone, flossing and reaming with guitar-wire of matching diameters. You need to physically poke out every bleed hole as no spray cleaners will remove dried gas varnish. You'll find when poking wire in, it pushes out little plastic plug like grain of sand out other side. Then drip dye down centre to verify every hole "bleeds" correctly.
You'll also most likely need to replace the float-valves since they're not sealing and dribbling petrol out vents.
Best bet for you is to get factory service-manual. Follow step-by-step 16-page guide to rebuilding carbs. There are no short-cuts.