On February 14, 2001, at 1230 hours Pacific standard time, a Piper PA-24-250, N8286P, experienced a loss of power during landing at the Petaluma Muni Airport, Petaluma, California. The airplane collided with a tree and impacted the ground 100 yards short of the runway. The airplane was owned and operated by the private pilot under the provisions of 14 CFR Part 91 as a personal flight, and sustained substantial damage. The pilot was not injured. Visual meteorological conditions prevailed. No flight plan had been filed. The flight departed the Sonoma County Airport, Santa Rosa, California, at 1145, and was scheduled to terminate at the Petaluma airport. An inspector from the Federal Aviation Administration (FAA) interviewed the pilot. The pilot stated that he conducted the prelanding checklist on downwind for runway 11, which included reducing power and lowering the landing gear. He saw the instrument panel flex forward and the engine began to run rough. He attempted to add power, but there was not a corresponding power increase. The pilot stated that he set the airplane up for best glide and continued the flight to the airport. About 300 yards from the end of runway 29 the airplane struck a tree. The airplane continued over a street and fence, where it came to rest about 150 yards from the departure end of runway 29. In the pilot's written statement to the Safety Board he indicated that the landing gear stopped about halfway down and then he felt a "severe" vibration. After the engine quit he continued in the pattern to set up for an emergency landing in an open field on airport property. The airplane was inspected on scene by an FAA inspector. He visually inspected the fuel tanks. Each outboard fuel tank had half a tank of fuel, and the main fuel tanks were full. During the inspection of the airplane, the FAA inspector noted that the mixture cable was entangled in the nose landing gear. When the landing gear was lowered, it pulled the mixture cable "out of its holder," which allowed the engine to be in a full lean position. The pilot informed the FAA inspector that he and his two partners had recently installed the mixture, throttle, and propeller cables. The FAA inspector reported that the pilot and his partners were not certified airframe and power plant (A & P) mechanics. He further noted that a certificated A & P mechanic had not returned the airplane to service. A review of the airplane logbook by the Safety Board investigator disclosed that the last entry was made on September 18, 2000.