To eliminate the generation of graphite during the no-load sudden accelerating operation without any increase in speed variation (governor difference) by improving the starting performance of an engine in a slope and quickening the rise of rotating speed of an engine at the time of cold starting.

A lever limit means 11 capable of freely advancing and retreating is disposed, facing to a first lever 1a, and the lever limit means 11 is driven to advance and retreat by an advance and retreat driving means 20A, whereby a start spring 2 is tensed and loosened by the lever limit means 11. At the time of starting an engine, the lever limit means 11 is retreated so that the start spring 2 is strongly pulled to position a rack pin 5 in a start increase position (Sr) through the first lever 1a, and after the engine is started, the lever limit means 11 is projected so that the start spring 2 is loosened and the excessive oscillation of the first lever 1a to the fuel increase side R is regulated by the lever limit means 11.