On July 12, 1993, about 0917 central daylight time, a Bellanca Decathlon (BL30); N4201Y, was destroyed and the private pilot was seriously injured when the aircraft experienced an engine problem, and impacted the ground. The pleasure flight, originating from Kenosha Municipal Airport, Kenosha, Wisconsin, was operating under 14 CFR Part 91 in visual meteorological conditions with no flight plan on file. The flight departed Kenosha, Wisconsin approximately 0715 CDT, for St. Jacob, Illinois, on the first leg of a cross country flight to Houston, Texas. The pilot's first planned fuel stop was to be St. Jacob, Illinois (3K6). Having filled the tanks on July 3, 1993, and making only a short trip from Delavan, Wisconsin to Kenosha, Wisconsin on that day, the pilot assumed she had 33.5 gallons of fuel left when she departed ENW for 3K6 on July 12, 1993. The pilot reported that "In the general vicinity of the Taylorville Airport, I noticed that the aircraft fuel gauges indicated that the fuel supply was lower than it should have been." She also noticed that the weather was deteriorating, and decided to locate an alternate airport, Taylorville Airport, to check her fuel supply, and also to get an updated weather briefing. The pilot contacted Taylorville on the Unicom frequency and described some landmarks to them to get a good heading toward the airport. Unable to discern her location, Taylorville suggested a 270 heading and a frequency. After contacting the facility, she was told to squawk a code. At this point, the engine began to sputter. The pilot stated that "It seemed as though I was running out of fuel, but this did not seem possible since I had only flown a little over two hours, and departed with enough fuel for over three hours of flight time." Realizing she would have to make a forced landing, the pilot lined up with a bean field, and set up for a landing in the field. The aircraft was destroyed during the forced landing. Investigation found the main fuel filter was approximately half full. The carburetor fuel filter was wet with no significant amount of fuel in the filter cavity. Inspection of the right wing fuel tank revealed a small amount of fuel in the lower rear inboard corner of the tank. The left wing came to rest, inverted, about hte right wing. While rolling the aircraft to expose the top of the left wing, approximately one half pint of fuel ran out of the fuel line from the left tank, which had been cut to facilitate the removal of the pilot. Probing the tank revealed less that a gallon of fuel remaining in the tank. Medical personnel stated that they noticed a definite lack of fuel smell or visible fuel during the removal of the pilot. Post-accident examination revealed no evidence of pre-impact mechanical malfunction with airframe, engine or accessories.