Engine cooling system for motorcycle

Abstract

A motorcycle having an improved frame and fuel tank arrangement that define a ram air inlet channel for delivering cooling air to the engine induction system.

I claim: 
     
       1. 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. 
     
     
       2. A motorcycle as set forth in claim 1 wherein the air inlet channel is inclined downwardly and rearwardly from an upwardly positioned opening to a rearwardly positioned outlet in registry with the air inlet. 
     
     
       3. A motorcycle as set forth in claim 1 wherein the air inlet includes a carburetor. 
     
     
       4. A motorcycle as set forth in claim 3 wherein the air inlet includes an air silencer for delivering air to the carburetor. 
     
     
       5. A motorcycle as set forth in claim 4 wherein the air inlet channel is inclined downwardly and rearwardly from an upwardly positioned opening to a rearwardly positioned outlet in registry with the air inlet. .Iadd. 
     
     
       6.  A motorcycle as set forth in claim 1 wherein the forward opening of the air inlet channel is defined by said facing side surfaces and said fuel tank lower surface..Iaddend..Iadd.7. A motorcycle as set forth in claim 1 wherein the engine is water cooled and further including a radiator positioned forwardly of the engine and below the facing side surfaces of the frame members and wherein a portion of the air directed to the air inlet passes through the radiator..Iaddend..Iadd.8. A motorcycle as set forth in claim 7 wherein the forward opening of the air inlet channel is defined by said facing side surfaces and said fuel tank lower surface..Iaddend.