On November 26, 2000, at 1950 central standard time, a Cessna 150L airplane, N18609, was substantially damaged when it impacted a tree during a forced landing near Valley Spring, Texas. The airplane was registered to a private individual and was operated by the pilot. The private pilot, who was the sole occupant, received serious injuries. Dark night visual meteorological conditions prevailed and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 personal flight. The cross-country flight originated from Pauls Valley, Oklahoma, approximately 1545, and was destined for the Rusty Allan Airport in Lago Vista, Texas. According to a written statement provided by the pilot, he departed Lago Vista and flew to Pauls Valley earlier in the day. Prior to departing Pauls Valley for the return trip, the pilot had the airplane refueled with 22 gallons of fuel. He then departed Pauls Valley and was navigating via VORs toward Lago Vista. The pilot stated that after he passed the Lampasas VOR, he selected a heading of 160 degrees to the Rusty Allan Airport. He later realized that he had missed the airport and started making "several large loops looking for landmarks." The pilot then realized that he was lost and elected to turn back and fly toward the Lampasas Airport. During the pilot's diversion, the engine lost power. The pilot attempted to restart the engine by pumping the throttle. The engine gained a few RPM, but did not restart. The pilot saw what appeared to be a vehicle and attempted to land on a road. During the approach; however, the airplane struck a tree and came to rest in a tree approximately 6 feet above the ground. According to the FAA inspector, who responded to the accident site, the airplane's cockpit area was torn open and the fuselage was structurally damaged. According to the aircraft salvage personnel, they removed 1 gallon of fuel from the right fuel tank and approximately 1 cup of fuel from the left fuel tank. On December 14, 2000, the engine was test run under the supervision of an NTSB investigator. According to the Cessna Aircraft Company representative, who was present for the test run, the engine ran rich regardless of the power setting. The engine was test run for 15 minutes at various power settings. According to those present during the test run and engine examination, the carburetor inlet filter was "90% blocked with a piece of black tape or a piece of rubber fuel line and particles." The bottom of the carburetor bowl also contained red/brown debris.