On April 13, 2006, about 1945 central daylight time, a Rumble/Williams/Boomhower Starduster II, amateur-built airplane, N7JC, was substantially damaged when the airplane nosed over during a forced landing at the Junction City Airport, Junction City, Kansas. Visual meteorological conditions prevailed at the time of the accident. The personal flight was being conducted under the provisions of Title 14 CFR Part 91 without a flight plan. The private pilot on board the airplane was not injured. The flight was originating at the time of the accident and was en route to Chapman, Kansas. The pilot reported taking off from runway 5 (1,927 feet by 200 feet, dry grass) at Junction City. He said he "Checked engine instruments as normal, applied power and everything was normal on take off. At approximately 150 - 200 feet agl (above ground level) the engine stopped suddenly with no indication of roughness or power drop of any kind." the pilot said he verified the throttle's position and pumped it with no resumption of power. The pilot attempted a forced landing on the remaining runway ahead of him. He said that on touchdown he attempted to stop the airplane before reaching a ravine in front of him. The pilot said he applied "hard brakes and held the tail high to increase braking effectiveness. Initially I could feel the wheels skidding on the grass. As speed began to bleed off, weight loaded on the tires, the brakes became more effective, and the aircraft nosed over onto its back adjacent to the end of the runway." An examination of the airplane showed substantial damage to the top wing and vertical stabilizer and rudder. The propeller was bent and the spinner was crushed aft. Flight control continuity was confirmed. An examination of the engine showed that the fuel lines had been routed to within 1-1/4 inches of the dual exhaust pipes. FAA requirements for certificated airplanes requires a minimum of 6 inches separation due to the potential for fuel in the lines to boil and subsequently cause a vapor lock in the lines. No other anomalies were found.