On small hp Tecusmeh carbs (3-12hp) there is a tube parallel at the side of the main jet tube that has a steel ball at the end. Some carb have one tube some have two. Sometimes a ball shows at the end of the tube. Sometimes there is something down in there further. The balls seem to be fixed in there. I've never seen one that would move. What is/are the tube(s) for? What is taking place in there and for what reason?