Abstract: A vibratory power unit (10, 210) having small gasoline engine (12) coupled by a drive shaft (15) extending through a semi-rigid shaft case (16, 18, 20) to an eccentric (75) rotating with the aid of sealed bearings (74, 78) within a vibrator case (14, 514) is disclosed. The semi-rigid shaft case includes a first rigid shaft case portion (16) and a second rigid shaft case portion (20) coupled together by an isolator (18, 518, 618). A coupling (90, 790) is provided for removably coupling the vibratory power unit (10, 210) to concrete finishing tools (11, 211). The coupling includes a split ball (92) configured to be received on the vibrator case (14, 514) and a slit ring (110) configured to compress the split ball (92) onto the vibrator case (14, 514). A radio controlled throttle controller (300, 400, 500) is provided for remotely controlling the speed of engine (12). Radio controlled throttle controller (300, 400) scavenges electrical power from the magneto circuitry of the engine (12).