On May 2, 2008, at approximately 1900 central daylight time, a single-engine Piper PA-22-108 airplane, experienced a total loss of engine power and was substantially damaged during the forced landing roll out. The commerical pilot, the sole occupant of the airplane, sustained minor injuries. The newly acquired airplane was owned and operated by the pilot. No flight plan was filed for the Title 14 Code of Federal Regulations Part 91 personal flight. The 92 nautical mile cross country flight originated from the Mc Comb Airport (MCB), Mc Comb, Mississippi, and was destined for the St. Landry Parish Airport (OPL), Opelousas, Louisiana. In a telephone interview with the NTSB investigator-in-charge, the pilot reported that he had purchased the airplane the day prior and was flying back to his home airport. On the final leg to his destination, the airplane's engine experienced a total loss of power after the pilot depleted fuel in the right fuel tank. The pilot attempted to switch from the right fuel tank to the left tank. The pilot stated that the fuel selector would not engage the left tank detent. After several attempts to seat the fuel selector in the left tank position the pilot elected to perform a forced landing to a wheat field. During landing roll, the nose gear impacted a rut which damaged the nose gear and resulted in the airplane coming to rest in the inverted position. The pilot was able to egress the airplane without assistance. The pilot walked several hours before reaching a road and receiving assistance from a passing motorist. The airplane was examined by the NTSB with the assistance of a technical representative from Piper Aircraft. All position detents could be identified from the fuel selector and the positions were verified from both wing tanks to the engine fuel line. Movement from the right tank to the left tank required a clockwise rotation which was impeded by a round head screw that was found slightly raised from the flush position. The screw secured the fuel selector placard to the side of the cockpit and when properly seated allowed for unrestricted movement of the fuel selector to all positions.