On January 22, 2013, about 1400 mountain standard time, a Goetz Helicycle, N143PG, experienced a hard landing following an off airport autorotation about 4 miles southeast of Falcon Field Airport (FFZ), Mesa, Arizona. The commercial pilot, the sole occupant, was not injured. The helicycle was registered to, and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed, and no flight plan had been filed for the flight that originated from Chandler Municipal Airport (CHD), Chandler, Arizona. The pilot reported that he had hovered the helicycle for about 15 minutes prior to a normal takeoff. During the flight, the engine suddenly lost partial power. The pilot initiated an emergency landing onto a residential road. A witness reported that his attention was first drawn to the helicycle when he heard an engine cutting in and out. Once the helicycle came into view, he noticed that it was also oscillating. The helicycle made a circle over his neighborhood before it initiated an autorotation to the ground. The helicycle landed hard and came to rest in a bush. During the accident sequence, the tailboom and tail rotor assembly were substantially damaged. Post-accident examination of the airframe and engine by a Federal Aviation Administration Inspector revealed that the fuel controller actuator motor arm was in the minimum fuel position. The electronic speed controller unit was damaged and separated from the helicycle. Several of the wires from this system were pulled from their ring terminals, including the "B" wire, which runs to the fuel controller actuator motor. All of these wires showed signs of being mechanically pulled from the ring terminal with the exception of the "B" wire, which did not have the same rough and tension markings. The pilot reported that the "B" wire had come loose at the connection while inflight. He further reported that when there is a loss of power to the fuel controller actuator motor the engine automatically goes to a minimum fuel stop position and flight idle. The pilot further reported that there were no parts failures, but that he had installed the "B" wire without an additional strain relief at the connector, which allowed the wire to disconnect from the system during normal operations. The pilot reported that the accident can be prevented by installing a second parallel wire between the fuel controller actuator motor and the electronic speed controller unit.