Engine cooling system for motorcycle

A motorcycle having a frame comprised of a head pipe, a pair of box section main frame members having inwardly facing side surfaces depending from respective upper surfaces, said main frame members being fixed at their front ends to said head pipe and extending rearwardly and downwardly therefrom, said inwardly facing side surfaces and said main frame members diverging from each other in the vicinity of their connection to said head pipe, a front wheel dirigibly supported by said head pipe, an engine carried by said frame and positioned at least in substantial part below said main frame members, said engine having a charge forming system including a rearwardly extending air inlet positioned at least in substantial part below said upper surfaces of said main frame members, a rear wheel suspended from said main frame member at the rear end thereof, and a fuel tank supported upon said main frame members and having a lower surface extending above said engine and said air inlet, said lower surface of said fuel tank and said inwardly facing side surfaces of said main frame members defining a forwardly opening air inlet channel for delivering ram air to said air inlet.