On October 1, 1997, at 1945 central daylight time, a Piper PA-28R-200, N1092X, piloted by a private pilot, was substantially damaged during an off-airport forced landing following a total loss of engine power. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 personal flight was not operating on a flight plan. The pilot reported no injuries. The flight departed Iowa City, Iowa, at 1725 with the intended destination of Nebraska City, Nebraska. The pilot stated that the engine lost power and he conducted a forced landing in a corn field. He made no statement as to the location of the fuel selector and did not indicate that he changed it from one tank to another prior to the loss of power. On inspection of the airplane the fuel in the right fuel tank was close to the top of the filler. The left tank was found to have only unusable fuel. On initial inspection the fuel selector was found on the left tank position. The Federal Aviation Administration Maintenance Inspector who inspected the wreckage reported he opened the fuel gascolator drain which the fuel tank selector still on the left tank and no fuel came out. When the selector was positioned to the right tank fuel ran out of the gascolator drain. The inspector's statement is attached to this report.