Air/fuel screw should be the gold screw that is to the left of the "longer" gold screw with the spring on it, (which is basically the idle screw) - it's on the left side of the bike for mine... sorry i don't have a pic to make it clearer!
make sure u count how many turns in the mixture screws in so if u stuff up u know the stock setting
Who's the Boss, is right the mixture screw is always seated into the carby body and the idle screw always has the spring