PURPOSE: To prevent engine stalling due to temporary overload by detecting the load condition of an engine, and actuating an actuator, operating an output adjusting means to an output increase side when a detected load exceeds a set value, to automatically recover the output of the engine.

CONSTITUTION: The output of a diesel engine E to be loaded on a working vehicle can be variously changed by oscillating the governing lever 2 of a governor 1. The governing lever 2 can be manually operated with a manual governing lever 4 interlockedly connected via a release wire 3. Moreover the governing lever 2 can be operated with an operation arm 7 driven with a servo type electric motor 6 as an actuator. In this case, a revolution sensor 10 is provided as a means detecting the load condition of the engine E. Also a control device 11 is provided as a control means automatically operating the electric motor 6 with the excess of the load of the engine E than a set value based on the information of the revolution sensor 10.