On April 10, 2005, about 1930 eastern daylight time, a tail-wheel equipped, experimental category, Shorethose Kitfox Series 5, N704LS, sustained substantial damage subsequent to a nose-over during landing at Jim Finlay Farm Airport (28FL), Crescent City, Florida. The airplane is owned by the pilot and was being operated as a visual flight rules (VFR) cross-country flight under the provisions of Title 14, CFR Part 91, when the accident occurred. The private pilot, the sole occupant of the airplane, was not injured. Visual meteorological conditions prevailed and no flight plan had been activated for the flight that originated from Donalsonville, Georgia, (17J), approximately two hours and thirty minutes prior to the accident. During a telephone conversation with the National Transportation Safety Board IIC, on April 12, the pilot reported that the airplane developed a rough running engine and he elected to make a precautionary landing. He stated the touchdown and initial rollout was normal, however the airplane encountered a soft/muddy area on the runway and nosed over. In a written statement dated April 19, the pilot reported that the "airplane made [a] precautionary landing and after rollout -during taxi to get off runway- airplane encountered a soft muddy area and flipped over." The pilot's statement made no reference as to the cause of the rough running engine.