On June 26, 2003, about 1110 Pacific daylight time, an experimental Pieterse Kitfox 2, N164JR, experienced a loss of engine power and made a forced landing in Corona, California. The owner/pilot 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 personal local flight departed Corona Municipal Airport (AJO) Corona, California, about 1105. Day visual meteorological conditions prevailed, and no flight plan had been filed. The primary wreckage was at 33 degrees 52 minutes north latitude and 117 degrees 31 minutes west longitude. In a telephone interview the pilot related that he had taken off from AJO on a local flight. The pilot said that he was about 2 miles from the airport when the engine started to run rough and then quit. The pilot made a forced landing in a dirt field, and during the rollout the airplane flipped over and came to rest inverted. The pilot reported that the right wing had damage to a rib and the left wing had damage to the strut. The airplane was recovered and transported to AJO for further investigation. The owner/pilot reported that the builder had routed the fuel pick up so that when flying in a nose down attitude, and with half tanks, the fuel was undeliverable to the engine. The owner changed the fuel system pick up and added an electric fuel boost pump to prevent a similar occurrence.