A fuel controlling apparatus includes: a fuel injector, the fuel injector being controlled on a basis of a throttle opening degree and an engine speed without measuring a quantity of an intake air; and a carburetor that supplies the fuel to the engine using a negative pressure produced by the intake system of the engine. The fuel is supplied to the engine solely by the fuel injector while the engine speed is lower than a lower limit of a high engine speed range including an upper limit engine speed. The fuel is supplied to the engine by both the fuel injector and the carburetor so that the fuel of a necessary quantity is supplied to the engine by combining a quantity of the fuel supplied by the fuel injector and a quantity of the fuel supplied by the carburetor while the engine speed is in the high engine speed range.