On July 30, 2003, at 1100 central daylight time, a Lancair 235, N7156W, registered to and operated by a commercial pilot, collided with the ground following a complete loss of engine power at Isbell Field, Ft. Payne, Alabama. The personal flight was conducted under the provisions of Title 14 CFR Part 91.Visual meteorological conditions prevailed at the time of the accident. The airplane was substantially damaged and the pilot received minor injuries. The flight departed Isbell Field, Ft. Payne, Alabama, on July 30, 2003, at 1030. According to the pilot, he removed the carburetor from the accident airplane to trouble-shoot another airplane. He reinstalled the carburetor on the accident airplane, and flew it for approximately 20 minutes. While on final approach to land on runway 4, the engine quit. The airplane collided with trees during an attempted emergency landing. Examination of the engine revealed no mechanical malfunctions. Examination of the carburetor control system revealed that the mixture control cable was not connected. The mixture control arm on the carburetor was in the idle cut-off position.