To select one of optimum data for engine type as a control object from a plurality of engine output characteristic data within control part by setting the resistance value of an external resistor laid outside the control part.

An external resistor OR is provided, so as to allow the adjustment of a control characteristic for every engine type. In other words, a plurality of engine output characteristic data D1 to Dn, and DABN, defining the control range of the position of a fuel injection volume setting rack corresponding to the preset engine speed are saved in an engine adjusting control part EC, thereby setting the resistance value of the external resistor OR outside the control part EC. Thus, an operation for selecting output characteristic data matching engine type as a control object from several types of output characteristic data D1 to Dn, and DABN can be made via the external resistor OR laid outside the control part EC. According to this construction, data can be easily selected.