I need to reinstall the rubber tubes on a King Canada Carburetor. One tube is OK. It goes from the fuel supply to the bottom of the carburetor on the right side. Another big tube is just for air. It's OK. The third tube, a small one, gives me a problem. There are three openings left, One on top, one below and one on the left side under the carburetor adjustment screw. What is the opening that should not be closed by the tube?