PURPOSE: To increase forward visibility and stability of machine body by eliminating the necessity for a fuel tank to be located above an engine so as to move the fuel tank downward.

CONSTITUTION: An electric fuel feed pump 82 powered from a flywheel magnet 202 is provided in a fuel feed pipe 85 for connecting a carburetor 83 to a fuel tank 81, and a return pipe 87 to return excess fuel to the fuel tank 81 through a three-way pipe 86 is connected to the outlet side of the fuel feed pump 82. In this way, fuel is led forcibly to the carburetor 83 by the fuel feed pump 82 not by utilizing gravitational head, and the necessity for the fuel tank 81 to be located over the carburetor 83 or an engine 2 is eliminated to move the fuel tank 81 downward.