05337722 is referenced by 31 patents and cites 60 patents.

Several embodiments of engines and systems for fueling engines to reduce the emission of unwanted exhaust gas constituents and to improve the fuel economy of the engine. A catalytic converter is provided in the exhaust system and a gaseous fuel is used at least during starting so as to bring the catalytic converter up to its operating temperature rapidly without necessitating the provision of an enriched fuel/air mixture. An oxygen sensor is employed in the exhaust system and a feedback control system varies the fuel/air ratio of the engine during its running in response to the output of the oxygen sensor. In order to test that the oxygen sensor is at its operating condition before feedback control is initiated, a rich fuel mixture is supplied and this rich fuel mixture is discontinued immediately upon the receipt of a signal from the oxygen sensor indicating that a rich mixture exits. Applications of the principal to both air valve type of carburetors and conventional carburetors are disclosed.

Title
Fuel control and feed system for gas fueled engine
Application Number
869373
Publication Number
5337722
Application Date
June 24, 1992
Publication Date
August 16, 1994
Inventor
Hiromatsu Matsumoto
Iwata
JP
Yoshikatsu Iida
Iwata
JP
Noriyuki Kurihara
Iwata
JP
Agent
Knobbe Martens Olson & Bear
Assignee
Yamaha Hatsudoki Kabushiki Kaisha
JP
IPC
F02M 21/04
F02B 13/00
F02B 43/00
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