Patents by Inventor Yuh Motoyama

Yuh Motoyama has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Exhaust timing control device for two-cycle engine
    Patent number: 5878702
    Abstract: An exhaust port controlling arrangement for an internal combustion engine having both main and auxiliary exhaust ports. A main control valve cooperates with the main exhaust port for varying the timing at which the exhaust port opens in response to engine speed. An on/off auxiliary control valve is positioned in a passage leading from the auxiliary exhaust port for opening and closing the flow through the auxiliary exhaust passage in response to an engine condition. Means retard the opening of the main exhaust port upon opening of the auxiliary exhaust ports to improve the power and torque curves of the engine.
    Type: Grant
    Filed: August 1, 1989
    Date of Patent: March 9, 1999
    Assignee: Yamaha Motor Corporation
    Inventors: Yuh Motoyama, Takafumi Fukuda, Yoshihiko Moriya