Abstract: An outboard engine with an automatic clutch to be used for a fishing boat arranged between the crankshaft of the engine and the propeller driving shaft. The automatic clutch comprises a main centrifugal clutch mechanism which is to be engaged at a revolutional torque close to the rated revolution of the engine and an auxiliary centrifugal clutch mechanism which transmits the torque between the shafts with a frictional slip at a revolutional torque which is produced at a rate lower than the above mentioned one. For operating at a higher speed, the propeller is driven by the transmitted revolutional torque through the said main centrifugal clutch mechanism while for sailing at a slower speed or at trolling, it is driven by the torque which is reduced in transmission by the slip effect in the auxiliary centrifugal clutch mechanism.