On September 3, 1995, at 1657 central daylight time, a Cessna 182, N5465B, sustained substantial damage when it impacted the terrain during a forced landing after takeoff in Walworth, Wisconsin. The pilot and one passenger reported minor injuries. Three passengers reported no injuries. The local parachute jumping flight originated in Walworth, Wisconsin, at 1655, and was conducted under 14 CFR Part 91 in visual meteorological conditions. No flight plan was filed. The pilot reported that he had flown eleven flights earlier in the day carrying parachute jumpers. He said one fuel tank was about 1/2 full, and the other about 1/4 full at the time of the accident. The fuel selector was in the "both" position. Immediately after takeoff, climbing through 550 feet AGL, the engine lost power. He lowered the nose of the airplane, established a glide, checked the engine controls and fuel selector, and pulled the carburetor heat control to no avail. At one point, "the engine started but would run at a fast idle, and for only a few seconds." He flew under a set of power lines, lowered the flaps, and conducted a forced landing in a soybean field. During the "full stall" landing, the nose gear collapsed and the airplane nosed over. One of the passengers, the jumpmaster, reported that prior to takeoff, the left fuel gage indicated 1/2 and the right fuel gage indicated "no takeoff". Several witnesses reported that they observed fuel leaking from the wreckage following the accident. The wreckage was examined by a Federal Aviation Administration (FAA) airworthiness inspector. He reported that the magneto switch and magnetos functioned normally. The induction air box was destroyed. All flight and engine controls exhibited no evidence of preimpact malfunction. Preliminary examination of the engine disclosed no abnormalities. Examination of the carburetor revealed a small scrape on the float. Examination of the fuel and fuel vent systems revealed no anomalies. The engine was tested at Teledyne Continental Motors, in Mobile, Alabama, on October 17, 1995. Examination of the carburetor revealed the mixture control arm was worn and could travel beyond the full rich stop. The original carburetor, a starter, a slave exhaust system, and thermocouples were installed. The oil pressure fitting in the left oil gallery was plugged. The engine was tested in a production test cell with the mixture control arm fastened in the full rich position and in the extreme rich position, beyond the full rich stop. The engine operated normally in each case and produced maximum rated power.