Abstract: A fuel tank system has a fuel tank, a fuel charging port extending from the fuel tank and disposed in the vicinity of an outer panel of a body and a fuel lid for covering the fuel charging port. The fuel lid is mounted such that it is movable substantially horizontally relative to a portion of the outer panel of the body corresponding to the fuel charging port and that a distal end of the fuel lid is capable of moving away from the fuel charging port and the outer panel. A fuel passage having an outlet disposed on a rear surface side of said fuel lid in such a manner as to be oriented downwardly is disposed in such a manner as to extend from said fuel tank. This fuel passage allows a liquid fuel overflowing during overfueling to flow.

Abstract: The fuel cutoff valve is provided which includes a case member having an outlet opening leading to a canister, and a float member disposed within the case member. The float member is provided including a valve which has a first annular seal member sealing the periphery of the outlet opening and a second annular seal member having a smaller diameter than that of the outlet opening, and a float body vertically below the values. A through hole in formed in each seal member of the valve. When the liquid fuel flows into the case and the floats member float the first seal member seals the periphery of the outlet opening. After the liquid fuel returns to the fuel tank, the valve is first opened between the second seal member having smaller diameter and the float body. Then since the valve also falls, even if the diameter of the outlet opening is large, the fuel cutoff valve will open.