Patent ID: 8881708

Claim:
A method comprising: receiving a first throttle control input, the first throttle control input comprising activation of a throttle control device within a first control range, the first throttle control input corresponding to a first output power of an internal combustion engine in a first output power range between zero and a transition output power level, the throttle control device causing operation of a mixture control carburetor to provide variation between at least a first air/fuel ratio and a second air/fuel ratio, the mixture control carburetor comprising separately actuated controls for movement of a slide that determines an airflow throat size and for movement of a tapered needle that is extendible and retractable from the slide into an orifice or jet to control a fuel delivery area of the orifice or jet; operating the internal combustion engine in a first operating regime in response to the received first throttle control input to deliver the first output power, the first operating regime comprising delivering, to a combustion volume of the internal combustion engine, inlet air and fuel to produce a first air-fuel mixture within the combustion volume, the first air-fuel mixture comprising the first air/fuel ratio; receiving a second throttle control input, the second throttle control input comprising activation of the throttle control device within a second control range, the second throttle control input corresponding to a second output power of the internal combustion engine in a second output power range between the transition output power level and a maximum output power level of the internal combustion engine; and operating the internal combustion engine in a second operating regime in response to the received second throttle control input to deliver the second output power, the second operating regime comprising delivering, to the combustion volume of the internal combustion engine, inlet air and fuel to produce a second air-fuel mixture within the combustion volume, the second air-fuel mixture comprising the second air/fuel ratio that is richer than the first air/fuel ratio.