does anyone know what the air fuel mixture screws on the front of the carbs are supposed to be set at from the factory ,my motor is a 1975 mercury 850 85 hp out board . there is a adjustment screw on the front of each carb I am assuming that they are the mixture screws? The motor runs awsome but seems to want to load up wile idleing .what rpm should the motor idle at ? really need some help!!!!!!!!