Abstract: A powered mechanism is described for controlling the dumping of mortar from a tilting mortar mixing drum. The powered mechanism is highly mechanically advantaged, so that a single operator has precise control of the dumping procedure. A mortar mixing drum has a rotatable paddle shaft and at least one paddle attached to it. The mortar mixing drum is operative between a home, mixing position, and a mortar dumping position. A drive mechanism is connected to the rotatable paddle shaft for rotatively driving the shaft and the paddle attached to it. A transmission mechanism has a ring gear attached to the mortar mixing drum and a pinion gear in rotative contact with the ring gear. The transmission mechanism also has a drive belt and a drive pulley rotatively attached to the rotatable paddle shaft. A hand-operated lever is engageable with the drive belt of the transmission mechanism to engage the drive belt for driving the transmission pulley, which causes tilting of the mixing drum.