On August 15, 1998, at 1130 eastern daylight time, a Cessna 305, N8WP, collided with the ground, according to the pilot, while attempting a takeoff from runway 15 at the Palm Beach County Air Park, in Lantana, Florida. The personal flight was operated by the pilot under the provisions of Title 14 CFR Part 91 with no flight plan filed. A review of weather data disclosed that visual weather conditions prevailed at the time of the accident. Examination of the airplane at the accident site disclosed that the airframe sustained substantial airframe damage. The commercial rated pilot and his passenger received minor injuries. The accident occurred during the initial takeoff from Lantana, Florida. The pilot reported that he completed an extensive preflight inspection that included the draining of both fuel sumps. According to the pilot, there was no sediment or water found in the fuel samples. During the preflight inspection, the pilot visually confirmed that both fuel tanks had been topped off, as he had requested, by the Fixed Based Operator. After the preflight inspection, the pilot taxied the airplane to the run-up area adjacent to runway 15. The pilot reported that the "pre-departure run-up" was normal. During the power application for the takeoff, the pilot recalled that engine operation was normal. As the airplane climbed through 400 feet, the pilot recalled that the engine hesitated and lost power. As the pilot attempted to correct the hesitation by adjusting the throttle, the engine backfired. Still above the runway, the pilot attempted a forced landing on the remaining runway. The airplane touched down on the runway, and rolled off the departure end of the hard surface into a grassy area. The pilot reported that the airplane nosed over as it stopped in the rough grassy area. According to the Fixed Based Operator, the airplane was placed back on the main landing gear during the recovery process. During the subsequent examination of the airplane both fuel tanks were drained of remaining fuel. During this phase of the recovery and examination, several ounces of water were also recovered from the left fuel tank. Examination of the airframe and sub-systems failed to disclose a mechanical problem. The fuel selector position was not determined.