On July 11, 1997, at 1900 central daylight time, a Bronner Steen Skybolt experimental airplane, N773HD, registered to and operated by the pilot as a Title 14 CFR Part 91 personal flight, was substantially damaged during a forced landing following a loss of engine power while maneuvering near Brazoria, Texas. Visual meteorological conditions prevailed for the local flight, and a flight plan was not filed. The private pilot and his passenger were seriously injured. The flight had originated from the Eagle Air Park Airport near Brazoria, Texas, about 15 minutes before the accident. During a telephone interview conducted by the investigator-in-charge and on the enclosed Pilot/Operator Accident Report, the pilot reported that prior to the accident flight he cleaned the fuel strainer and fueled the airplane with 15 gallons of 100 octane low lead aviation fuel. The pilot further reported that about 1845, he "took [the] Skybolt up for a run around the patch at Eagle Air Park." After about 12 minutes while on cross wind for runway 11, he smelled "raw fuel, looked down on floor board, [and] saw fuel." The fuel pressure which is normally 30 psi, began to fluctuate "radically," and the engine "cut out." He turned on the electric fuel pump, and the engine "came back up to power." After turning final the engine started "cutting in and out, [the] fuel pressure could not be kept up," and the engine lost power. He took a quick look at the visual fuel indicator, and it showed the fuel level between the 2 and 4 gallon marks. With no place to land he intentionally stalled the aircraft into the trees. The aircraft "hit [the] ground flat and in an area about 150 feet square." According to a witness, the airplane was flying east of the airport when he heard the "engine start missing and [the] power go away. Then [the] power came back again." The aircraft entered downwind and the "engine went away again." After the aircraft turned final approach, "the engine barely came back and then no engine noise at all." Witnesses reported that when they arrived at the crash site there was no smell of fuel. Examination of the airplane at the crash site by the FAA inspector revealed that the airplane came to rest upright .2 miles from the approach end of Eagle Air Park Airport's runway 11. Examination of the airplane's fuel system revealed no apparent signs of rupture or lack of integrity, and there was no fuel in the fuel tank. The airplane sustained structural damage to the left wing and empennage, and the main landing gear were separated from the fuselage. The airplane's engine was partially separated from the fuselage. Another FAA inspector examined the airplane after it was moved to a hangar. When the FAA inspector pumped the wobble pump, he could smell fuel; however, he could not see where the fuel was coming from due to the location of the wobble pump and its fuel hoses. The pilot reported to the investigator-in-charge that he examined the airplane's fuel system and found one of the hoses that was connected to the wobble pump, which was located under the pilot's seat, had been leaking fuel at its clamp. He also found fuel stains on the fabric aft of the wobble pump.