PURPOSE: To facilitate starting by coupling first and second supporting levers between a control level and a floating lever in such a way as swinging freely each other.

CONSTITUTION: First and second supporting levers 26, 29 are coupled between a control lever 33 and a floating lever 24 in such a way as swinging freely from each other. If a lever 52 is detained with a plate 58 when a stop device lever 52 is put in stop mode, a control rack 53 is drawn in the direction of fuel reduction against the action of a start spring 56, and the other end of floating lever 24 coupled with a joint 55 is displaced in the same direction. In this condition, the rotary displacement of a torque cam 42 is secured to a certain extent, and a notch 43 is held in the range of a detained pawl 48 revolving. This will facilitate starting.