| 摘要 |
PURPOSE:To enhance the rigidity of a crank casing while its weight is restrained, and as well to enhance the durability of an engine entirely, by providing a reinforcement formed therein with a hole through which a connecting rod may be inserted, to the crank casing in the part corresponding to engine cylinders. CONSTITUTION:In an upper crank casing 13, a reinforcement 40 formed with a hole 39 through which a connecting rod 34 is smoothly inserted, is provided to the position facing a storing hole into which a wet sleeve 25 is inserted. With the provision of the reinforcement 40, the rigidity of the upper crank casing 13 is greately increased and the durability of an engine is remarkably enhanced. |
