PURPOSE: To reduce the size of the titled apparatus for turning a shaft in both normal and reverse directions, by supporting a gear, a lever and a turning wheel on a support shaft, and providing a means for transmitting the engine torque to the turning wheel via a centrifugal clutch and controlling supply of mixture gas.

CONSTITUTION: A gear 2 and a lever 3 are supported on a support shaft 2a, and a load 1 is driven by the gear 2. A support shaft 6a is driven by an engine 7 via a centrifugal clutch 7a. When a lever 15 supported on a support shaft 15a is turned clockwise, a valve 7b for supplying mixture gas to the engine is opened and increases the engine output. When a lever 3b is pushed manually to the left, a lever 16 is urged onto a contact portion 3c, so that the lever 15 is turned clockwise. The load 1 is driven in normal direction, and the driving speed of the load 1 can be changed according to the turning angle of the lever 3b. Thus, it is enabled to turn the output shaft of a small engine in both of normal and reverse directions with ease.