Abstract: A hydraulic pump is mounted on a bracket which, in turn, is mounted on a frame secured to a marine engine. The mounting of the frame on the engine allows for substantially universal swiveling and translation adjustment to position a rearward-projecting stub shaft of the frame stationarily and in coaxial alignment with the forward-projecting front end portion of the engine crankshaft. A cogwheel or pulley is rotatably mounted on the stub shaft and is joined to the engine crankshaft by a flexible coupling. Such cogwheel or pulley drives a belt which powers the driven input wheel or pulley of the pump. The substantial tension of the belt is applied to the stub shaft of the frame without transmission to the engine crankshaft, and the coupling of the pump to the engine is not effected by vibration, twisting or fore-and-aft surging of the engine in response to developed torque and thrust.