On April 28, 2004, at 1415 eastern daylight time, an amateur built Kitfox, N917JB, was substantially damaged during a forced landing, following a loss of engine power, in Mount Sterling, Kentucky. The certificated private pilot received serious injuries, and the passenger received minor injuries. Visual meteorological conditions prevailed and no flight plan was filed for the flight which departed the Dayton-Wright Brothers Airport (MGY), Dayton, Ohio, and was en route to the St. Petersburg-Clearwater International Airport (PIE), St. Petersburg, Florida. The personal flight was conducted under 14 CFR Part 91. According to the pilot, he performed a preflight inspection on the airplane, and departed MGY about 1345 with full fuel. Approximately an hour later, while en route to PIE, the airplane's engine sputtered several times, and then lost power completely. The pilot flew toward the Mount Sterling-Montgomery County Airport, and when he realized he would not make it to the airport, he chose a field to land the airplane in. During the landing, the landing gear collapsed, and the airplane sustained substantial damage. The Rotax engine was retained and examined under the supervision of an FAA inspector. The examination revealed that the inlet finger screens of both the primary and auxiliary fuel pumps were 80-90 percent blocked with contamination. No additional mechanical deficiencies were noted with the engine. A download of the Turbo Control Unit (TCU) revealed the engine had accumulated 107.5 hours of operational time. Additionally, the RPM data indicated the engine never produced full power on the flight prior to the accident. A Federal Aviation Administration (FAA) inspector stated prior to the accident flight, the airplane had only been flown 9-10 times during the previous 14 months. The inspector reviewed the aircraft and engine logbooks and reported that the last condition inspection was performed on April 12, 2004, at which time the accident engine was installed. One additional entry, for a test flight, was observed in the logbooks since the last inspection. Review of the operator manual for the Rotax engine revealed, "Danger! This engine, by its design, is subject to sudden stoppage! Engine stoppage can result in crash landings. Such crash landings can lead to serious bodily injury or death. Never fly the aircraft equipped with this engine at locations, airspeeds, altitudes, or other circumstances from which a successful no-power landing cannot be made, after sudden engine stoppage." The manual further stated, "Warning! This is not a certificated aircraft engine. It has not received any safety or durability testing, and conforms to no aircraft standards. It is for use in experimental, uncertificated aircraft and vehicles only in which an engine failure will not compromise safety. User assumes all risk of use, and acknowledges by his use that he knows this engine is subject to sudden stoppage."