On November 12, 1999, about 1345 Eastern Standard Time, a homebuilt Sea Hawk, N101WR, was substantially damaged during liftoff from Somerset County Airport (2G9), Somerset, Pennsylvania. The certificated private pilot was not injured. Visual meteorological conditions prevailed and no flight plan was filed for the flight conducted under 14 CFR Part 91. The pilot arrived at 2G9 on November 11, 1999, to examine the aircraft documents and taxi the airplane to become familiar with it and "get a feel for the brakes." The following morning, the pilot performed several high speed taxi runs to "test the brakes" using 3/4 of the 4,697 foot runway. Later that afternoon, the pilot wanted to perform the same taxi tests, using different increments of flaps to determine how the airplane would perform. The airplane was taxied about 1/3 the distance down the runway, with the flaps lowered, and power was added. As the airplane "lifted slightly off the runway," about 8-10 feet above the ground, the "engine quit" and the airplane "pitched over to the left." The engine then regained power, and the pilot decided to land. During the landing, the airplane made numerous contacts with the ground over a distance of 75 feet. The pilot additionally stated that he had no intention of flight on the day of the accident and when the airplane impacted the ground, "it wasn't really flying." A Federal Aviation Administration (FAA) Inspector, who examined the airplane after the accident, stated that when he drained fuel from the main tank, located on the upper wing, he discovered red particles, "bigger than pepper flakes," similar to the lining of the fuel tank. The drained fuel was consistent with that of aviation fuel. When the Inspector drained fuel from the auxiliary tank, located on the lower wing, it resembled "pond scum," and contained an odor consistent with that of a mixture of aviation fuel and automobile gasoline. The Inspector further stated that the airplane had been sitting on the ramp, without being flown, for five years. A mechanic stated to the FAA Inspector that fuel was added to the airplane's main tank on November 11, 1999, and he drained a sample. The main tank was topped off with 16 gallons of fuel, on November 12, 1999. No fuel was added to the lower auxiliary fuel tank on either day.