On July 15, 2001, about 1900 eastern daylight time, a Cessna 175, N8861E, registered to private individuals, operating as a Title 14 CFR Part 91 personal flight, impacted in a tree shortly after departure from the Lake Norman Airpark, near Mooresville, North Carolina. Visual meteorological conditions prevailed, and no flight plan was filed. The airplane was substantially damaged. The commercial-rated pilot, and a student pilot reported serious injuries. Both occupants were co-owners of the airplane. The flight had just departed when the accident occurred. According to the pilot the engine was surging as the airplane started its takeoff roll. When the airplane became airborne the pilot reported he could not maintain altitude and elected to make a forced landing, coming to rest upside down in a tree about 40 feet above the ground. He stated that after departure from his home airport he was flying solo, and had landed at another airport. He landed, taxied around, and on takeoff, "...the engine didn't feel right on full throttle..…at this point I was uncomfortable with the airplane," and decided not to fly any more. He called his wife to pick up a co-owner of the airplane to help him find the problem. The co-owner flew the airplane in the pattern and landed twice. Then together they flew two takeoffs and landings without finding the problem. They decided to fly to another airport to see if the problem would surface again, and it did not. They then decided to fly to the airport where the accident eventually took place. They landed twice, and on the second takeoff the pilot stated "...the problem showed up, landing us in the trees." According to the FAA inspector, the airplane's type certificate, and weight and balance indicated that 9 gallons of fuel were unusable. The owner/student pilot was under the impression that the airplane had 2 gallons of unusable fuel. The fuel burn for this airplane was 10 to 10.5 gallons per hour in level flight. Each fuel tank held 26 gallons, for a total of 52 gallons, or 43 gallons of usable fuel. The fuel tanks were topped off on June 28, 2001. The FAA inspector stated that the owner/student pilot did not log all the time since last refueling the airplane, but had logged 3.98 hours. At 10.5 gallons per hour, 41.79 gallons of fuel would have been used in 3.98 hours. Examination of the fuel system after the accident, and after the airplane was removed from the trees, revealed that about 2 gallons of fuel was drained from the left tank, and no fuel was found in the right tank. The fuel that was drained was "..…clean with no evidence of sediment or water." In addition, there was no evidence of fuel leaks found at the accident site. No fuel odor was noted. The inspector further stated, when the propeller was pulled through, "...all cylinders had compression and there was ignition (spark)." A teardown of the carburetor revealed that safety wire was used in place of a cotter pin, but "...nothing that would have an adverse affect on performance of unit/engine."