On November 11, 2006, about 0930 central standard time, a Cessna 150J, N50977, registered to and operated by a private individual, as a Title 14 CFR Part 91 personal flight, nosed over while making a forced landing following loss of engine power in Defuniak Springs, Florida. Visual meteorological conditions prevailed, and no flight plan was filed. The private-rated pilot and one passenger were not injured, and the airplane incurred substantial damage. The flight originated in Defuniak Springs, the same day, about 0925. The pilot stated that in preparation for his flight he performed a preflight examination of the airplane, and during the preflight, shook the airplane’s wings well, and sumped both fuel tanks into a GATS jar, until no evidence of water existed in the sample, adding, "you always get a few drops in a Cessna." He said he then opened the cowl access and drained the sump, which contained some water as well so he emptied the jar and activated the drain again, this time obtaining a clean sample. He then used a small stool and checked both wing with the calibrated tube he had purchased for that purpose, and the tube showed that that there were 8 gallons in the right fuel tank, and 7 gallons in the left. The pilot said he then confirmed that both fuel tank caps were secure, and continued his preflight. According to the pilot, everything looked good, so after completing his preflight examination, he started the airplane's engine and completed other items to initiate the flight. He said he performed the static power check per the operator's manual , at 1,600 RPMs, checked the magnetos, carburetor heat, and verified that "T and Ps" were all in the green range, and then taxied to runway 27. The takeoff was uneventful, and the pilot said that his intention was to remaining in the pattern. While on left downwind to land on runway 27, about the end of the runway, the pilot said that the engine backfired 2 or 3 times quickly, as he retarded the throttle control to reduce power and make the approach. He said he did not think too much about it, because he thought he had possibly retarded the throttle control too quickly. While on final approach he said he was a bit too high so he pushed the throttle and carburetor heat controls forward, and did a full power low pass over the runway. He said the engine was operating fine, and it developed full power as he climbed out. While still climbing he pilot said he turned crosswind, and during the turn to left downwind, the engine "back popped a few times and lost all power." According to the pilot, the engine went completely dead with no power at all, and the propeller was just windmilling. He said he kept making the turn while keeping the angle of bank shallow to avoid a stall, and headed to runway 9 which was close. The pilot said he was about 700 to 800 feet at best, and he avoided trees and tried to align with the runway, but the airplane was descending fast and he touched down on a cross taxiway at the end of the runway. During the landing rollout the nose-wheel dug into the soft dirt and the airplane nosed over, incurring damage. An FAA inspector and a representative of Teledyne Continental Motors performed a postcrash examination of the aircraft. The examination revealed evidence of rust in the carburetor bowl and evidence of heavy corrosion in the bottom of the gascolator bowl, however no anomalies were noted which would have precluded engine operation.