PURPOSE: To reset the engine condition to the engine rotating condition before the interruption of the work quickly and easily at the time of starting the work again by moving a speed control lever to the idling position with an output shaft, which stops at each half rotation, preferencially to an operating lever of an engine at the time of interruption of the work.

CONSTITUTION: A speed control lever 2 off an engine and an operating lever thereof are connected by an inner cable 4. An operating arm 18 is fitted to a speed control lever side end 16 of an outer cable 14 freely to reciprocate. Furthermore, a motor 28 for driving the reciprocation of the operating arm 18 is fitted to the operating arm 18. When an operating switch with return spring is turned on, the motor 28 is operated. On the other hand, when the output shaft 30 is turned half and a position detector 38 outputs the detecting signal, the motor 28 is stopped. Namely, the output shaft 30 is turned half each time when the operating switch is turned on, and the idling of an engine and the reset to the engine speed corresponding to the operating quantity of the operating lever are thereby performed alternately.