Abstract: A vaporized fuel controller for a carburetor which utilizes the negative pressure in the intake manifold and electromagnet to actuate a changeover valve so as to connect the gas chamber of the float chamber to the inner vent when the engine is running, and to the canister when the engine is not running. With this invention, when the negative pressure in the intake manifold decreases while the engine is running at high speeds, the electromagnet keeps the valve from being moved by the spring force and maintains the valve at a position such that the vapor fuel is supplied to the intake manifold through the inner vent.

Abstract: A carburetor in a fuel system in a motor vehicle including a fuel tank, a fuel pump for delivering fuel from the fuel tank to the carburetor under pressure and the return line which returns fuel from the carburetor to the fuel tank when an excess amount of fuel is delivered to the carburetor by the fuel pump. The carburetor further includes a check valve means in the return line for preventing the flow of fuel in the return line in a direction from the fuel tank to the carburetor whereby leaking out of fuel from the carburetor of fuel flowing backwards through the return line is prevented when the vehicle is turned upside down in an accident.