A system and method are provided for controlling an internal combustion engine driving a generator/welder or a stand-alone generator. Controlling the engine may include altering the engine speed based upon a detected demand on the generator and/or operating parameters of a welder. For example, the engine speed may be increased based on a detected draw on the generator and/or the operating parameters of the welder. In addition, the engine speed may be automatically decreased to a non-standard idle speed or the engine may be automatically turned off if no demand is detected for a period of time. Additionally, the engine speed may be increased if only frequency-insensitive demands are detected on the generator. Combinations of these and further methods may be executed. Various devices are provided for implementing the above methods.