On September 18, 2010, about 1257 eastern daylight time, a Globe GC-1B, N3348K, was substantially damaged when it impacted trees and terrain at Briar Patch Airport (9GA1), Clyo, Georgia. The airplane was owned and operated by the pilot. The certificated commercial pilot was seriously injured, and a pilot-rated passenger received minor injuries. Day, visual meteorological conditions prevailed at the time, and no flight plan was filed for the personal flight to Midway, Georgia (9GA2). The flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. The flight was originating at the time of the accident. The pilot reported that after breaking ground with the runway, a noticeable loss of engine power occurred. He checked the engine controls full forward, however this did not remedy the situation. He retracted the landing gear and attempted to gain enough altitude to clear the departure end trees. Realizing that the airplane would not clear the trees, he pulled hard aft on the stick to strike the trees flat rather than head-on. The airplane collided with the trees, then the ground and nosed over. The passenger, who was a certificated private pilot, reported that the pilot positioned the airplane for takeoff on runway 34. He observed the propeller, throttle, and mixture controls forward, and felt the tail come up during the takeoff roll. As the airplane "began to fly it did not seem to accelerate." He recalled that the engine tachometer read between 2,650 and 2,700 rpm during the takeoff roll and climb, and that the engine sound was normal. He sensed that the airplane would collide with trees at the end of the runway. The right wing struck the trees first, "then we rolled over." A witness, who was standing beside the runway, observed the airplane prior to taxi. He stated that the engine started normally and "sounded as if it was running smoothly." He reported that the winds were light and variable and the wind sock was "limp." During the takeoff roll, the engine "still sounded smooth." At the mid-field point on the runway, the airplane had not yet lifted off, "and did not seem to be accelerating like it should. With very little runway remaining, the airplane lifted off at a high angle of attack and climbed sluggishly to approximately 25 to 35 feet agl. It then began to settle, in a steep nose up attitude, and disappeared behind the trees off the departure end of the runway." The takeoff roll was videotaped by a bystander and a copy of the video was provided to an inspector with the Federal Aviation Administration. Examination of the footage revealed that, during the takeoff roll, the pitch attitude of the airplane increased, and the tailwheel appeared to re-contact the grass surface for about three seconds before the video ended. The liftoff and airborne portions of the flight were not recorded. The engine sound during the takeoff roll was consistent with a normal operating engine at takeoff power. The wreckage was examined at a salvage facility on February 14, 2011. The fuel tanks were examined and no water or particulates were observed. The fuel lines and vents were unobstructed. Both fuel tank filler caps were secure and the rubber seals were pliable. There was no fuel in the left tank and about one inch of light blue-colored fuel in the right tank. The engine was removed from the airframe and secured to a forklift. The top spark plugs were removed and inspected; the electrodes were normal in color and wear when compared to a Champion inspection chart. Internal engine continuity was confirmed and valve action was correct. There was impact damage to the exhaust system, engine mount, and fuel control linkages. The engine rotated freely when the propeller was rotated by hand. A fuel source was plumbed to the inlet of the engine-driven fuel pump. The starter was energized and the engine started after priming. The engine ran normally, however when the throttle was retarded from full forward, the engine stopped running. Three attempts were made with the same results. The fuel injection servo was removed from the engine and sent to Avstar Fuel Systems, Inc., Jupiter, Florida for further evaluation. An air safety investigator with the NTSB Miami, Florida office provided oversight of the inspection. The fuel injection servo met all of the manufacturer's specifications when the unit was tested, except for an extra lean setting at idle (measured 15 pounds per hour (pph) versus a normal range of 22 to 28 pph). There were no discrepancies noted that would have prevented normal operation of the fuel injection servo. Weather, recorded at Savannah/Hilton Head International Airport, Savannah, Georgia, located about 21 miles south of 9GA1, at 1253, included winds variable at 4 knots, visibility 10 statute miles, scattered clouds at 3,600 feet, ceiling broken at 18,000 feet, temperature 30 degrees C, dew point 21 degrees C, an altimeter setting of 30.09 inches Hg.