A water jetting nozzle includes a housing assembly and a hollow shaft extending longitudinally within the housing assembly and having a shaft proximal end adapted to be connected in fluid communication with a high pressure water line, and a shaft distal end. A rotating head is secured to the shaft distal end, the rotating head including at least one water jet orifice. A magnetic rotor is seated on the shaft and a conductor sleeve is located within the housing assembly, the conductor sleeve having a longitudinally extending bore adapted to receive the magnetic rotor. A longitudinal position of the conductor sleeve is selectively movable relative to the magnetic rotor between a first position in which the magnetic rotor is generally located within the bore, and a second position in which the magnetic rotor is at least partially external of the bore.