On May 19, 2006, about 1115 Pacific daylight time, a Piper PA-24-250, N7857P, performed a gear up forced landing following a loss of engine power near Carson City, Nevada. The owner was operating the airplane under the provisions of 14 CFR Part 91. The private pilot, the sole occupant, was not injured; the airplane sustained substantial damage. The cross-country flight departed Rio Vista, California, municipal airport about 1010, with a planned destination of Minden, Nevada. Visual meteorological conditions prevailed, and no flight plan had been filed. The pilot submitted a written report. He departed Rio Vista and flew north of Reno at 9,000 feet to avoid bad weather over Lake Tahoe. He contacted Reno approach control 10 miles east of Truckee, California, and stayed in contact with them throughout the flight. At this point, the pilot experienced a loss of engine power. He pulled the carburetor heat on first, and then turned on the auxiliary fuel pump, but power was not restored. The pilot then turned the fuel selector from the main fuel tank to the left auxiliary tank and waited for 1 minute. Power was still not restored. He switched to the right auxiliary fuel tank, but still nothing happened. The pilot attempted to restore power by using the primer to pump fuel to the engine. While troubleshooting the problem, the pilot was in contact with Reno approach control about his situation. After failing to restore engine power, the pilot committed himself to an emergency landing in an alfalfa field east of Washoe Lake. After clearing power lines, the pilot extended full flaps and opted not to extend his landing gear. A Federal Aviation Administration inspector examined the airplane at the accident site, and submitted a written report. The inspection revealed that both main fuel tanks were completely dry and both auxiliary fuel tanks were full. The inspector placed the fuel selector on the auxiliary tank, and turned on the boost pump. After several seconds, the fuel system pressurized, and operated normally. He found no mechanical problems with the fuel system or the airplane. According to the Piper Comanche, PA-24-250, Pilot Operating Handbook, the most common cause of an engine failure is mismanagement or malfunction of the fuel system. In this situation, the handbook says the first thing the pilot should do is "move the fuel selector valve to the tank not being used." This will often keep the engine running if there is no fuel system malfunction. If switching the fuel selector does not restore the engine, the pilot should check fuel pressure, turn on the electric fuel pump, push mixture control to full "RICH," apply carburetor heat, and check the ignition switch.