On June 25, 1994, at 1300 central daylight time, a Mueller Q2, N524WM, piloted by the owner/builder, experienced a loss of engine power during cruise flight in the vicinity of Utica, Nebraska. The homebuilt airplane was destroyed when it nosed over during the subsequent forced landing. The private pilot received serious injuries. Visual meteorological conditions prevailed for the flight, no flight plan was filed. The flight operated under 14 CFR Part 91, and originated from York, Nebraska, approximately 1245. The pilot stated the airplane was in cruise flight at 3,000 feet Mean Sea Level (MSL) when "...my engine went to idle and I could do nothing to get power back." He reported he set the airplane up for its best glide and looked for a field for the forced landing. The pilot reported all the fields were corn fields. He selected a corn field with the rows aligned into the wind, and set up to land. The pilot stated: "I had a controlled approach but as the plane touched down the 4 foot high corn and soft dirt flipped the aircraft over and it landed on its canopy." Postaccident investigation revealed the carburetor float needle valve was stuck in the closed position. The valve seat stuck repeatedly during postaccident examination (see Inspector Statement.) The pilot reported the carburetor total time was 23.4 hours. The most recent inspection was an Annual Inspection which was dated August 29, 1993. The carburetor had 7.6 hours since the Annual Inspection. The pilot stated he "...could have cleaned carburetor after sitting for the winter...this may have prevented the accident."