On January 17, 2004, about 1130 mountain standard time, a PA 22-160, N8718D, lost engine power during cruise, and the pilot made an off airport emergency landing approximately 15 nautical miles east of Carefree, Arizona. The pilot, also the registered owner, was operating the airplane under the provisions of 14 CFR Part 91. The airline transport pilot, the sole occupant, was not injured; the airplane sustained substantial damage. The flight departed Payson Airport (PAN), Payson, Arizona, about 1100, en route to Falcon Field (FFZ), Mesa, Arizona. Visual meteorological conditions prevailed, and no flight plan had been filed. In a telephone conversation with the National Transportation Safety Board investigator-in-charge, the pilot reported that during cruise flight, the engine lost partial power. He went through his emergency checklist, but the engine did not regain power. The pilot continually applied the primer to maintain the engine speed between 1,200 and 1,500 rpm. He landed on a beach at Bartlett Lake, and collided with rocks during the landing roll. The pilot manually shut the engine down. Recovery personnel reported that the right fuel tank was empty, and the fuel selector was on the right tank. A Federal Aviation Administration (FAA) inspector supervised examination of the airplane at Air Transport, Inc., Phoenix, Arizona. Recovery personnel started the engine, and successfully ran it up to 2,300 rpm.