On May 25, 1996, at 1540 eastern daylight time, an experimental Fisher Classic, N6292B, sustained substantial damage when it hit trees during a forced landing due to loss of engine power. The commercial pilot received minor injuries. The 14 CFR 91 flight departed Mooresville, Indiana, on a local flight. Visual meteorological conditions prevailed and no flight plan was filed. The pilot reported that it was the first flight of his home built airplane. He reported that he had built the aircraft himself, and bought a used aircraft engine which had 211 total hours on it. He installed a new aviation certified fuel pump on the engine before the flight. The aircraft had been registered with the Federal Aviation Administration (FAA). However, it had not been inspected for airworthiness by the FAA and had not been certified prior to the first flight. The pilot reported that during the preflight all instruments checked normal. He reported that the aircraft was sluggish in the climb. He climbed to 700 feet above ground level (AGL) and flew for 12 minutes, and then the engine quit. He reported that he could not get to an open field, and landed in a wooded area. He reported the airplane landed in the trees which cushioned the impact with the ground. The pilot reported that he thought the engine had seized. He also indicated that he thought the prop had been set at too high a pitch, 14 degrees, and it may have required the engine to work too hard to maintain flight. He reported that he could not get the engine to produce more than 6000 RPM's at full throttle. He reported that he had been at full throttle for the entire 12 minutes. The examination of the aircraft revealed that the engine had not seized. The pistons and cylinder walls were examined for overheating or seizure, and none was found. The carburetors were disassembled and no discrepancies were found. The exhaust manifold was removed and the were no indications of a rich fuel mixture or scored pistons. The fuel tank was inspected and no discrepancies were found. The fuel pump was inspected and it was determined that the pump was an aviation fuel pump with the designed "weep hole." However, the fuel pump's inlet and impulse hoses had sharp bends in them. The prop was rotated and the engine exhibited continuity.