Fuel injection system in an engine for a small-type vehicle

In a small-type vehicle including a cylinder head possessed by an engine main body mounted on a vehicle body frame, an intake passage portion extending rectilinearly so as to guide cleaned air from an air cleaner disposed on the upper side of the cylinder head, the intake passage portion being connected to an upper portion side wall of the cylinder head, an injector for injecting a fuel into the intake passage portion from the upper side, the injector being attached to the air cleaner, and a fuel tank so disposed as to cover a rear portion and an upper portion of the air cleaner, to make it possible to secure a sufficient capacity of the fuel tank. In the invention, the injector 100 is disposed on the front side relative the center line C1 of the intake passage portion 92.