I have a 2004 Vstar it will only start and idle when the choke is fully on, but immediately dies when I turn down the choke or turn the throttle? I've changed out the fuel, replaced the fuel filter, replaced the spark plugs and removed the air filter. Still no luck? I've attempted to clean the carb and run some Gumout carb cleaner through it, But must admit I don't know what I'm doing with the carbs? Any suggestion on what to do or look for? (Thanks!)