ok, chokeing the engine means its starving for gas, your putting more gas into the carb when its needed, definetly clean out the carb. sounds to me the secondary is free flowing, but the idle feed is clogged, there are tiny, tiny little holes in the side of the intake of the throat of the carb, may be 2 0'cliock maybe 10 o'clock. or 3- 9. they are there and they mean alot to the carb. shoot every orfice of the carb, take out ever screw exepct the main, its a bitc* to get out on the old carbs, but make sure its free flowing with carb cleaner. this definetly sounds like restriction of fuel