| 摘要 |
PURPOSE:To sufficiently heighten the cooling effect to an engine and the carburetor, and also th enhance the heat exchange effectiveness of the radiator by arranging the radiator so as to be inclined with the rear side down, extending from the front end of the fuel tank bottom surface to the rear upper end of the engine cylinder head. CONSTITUTION:The bottom surface 17 of a fuel tank 9 is inclined so as to be high at the front end and to be gradually lowered toward the rear, so that a recessed chamber 17a can be formed between both side surfaces. Extending from the front end of the bottom surface 17 to the rear upper end of the cylinder head 18 part of an engine, a radiator 19 inclined with the rear side down is arranged. The upper half of the radiator 19 is housed inside the recessed chamber 17a. The running air B introduced from an air introducing port 24 passes through a duct 25, the recessed chamber 17a, and a passage 28, and in the course of passage, it passes through a radiator 19 to cool engine cooling water by heat exchange. Since the running air B heated by the heat exchange makes a straight pass to the passage 28, it does not come into contact with a carburetor 12, which is therefore prevented from being heated. Rather, the flow velocity thereof sucks the running air A beneath the carburetor 12 to accelerate the cooling thereof. |
