US Patent 7832196 Electronic emissions control

A method of controlling emissions from an internal combustion engine including governing engine speed with respect to a constant speed, maintaining an air/fuel ratio of the engine, flowing exhaust from the engine through an exhaust system containing a catalyst, monitoring a variable with a feedback sensor located upstream of the catalyst, and controlling the air/fuel ratio of the engine as a function of the variable. In one application, the engine is configured for marine applications, including electric power generation and propulsion.