On September 20, 2008, at 0945 Pacific daylight time, N3440, a Stearman C3-B, collided with a tree during a forced landing near Stevenson, Washington. The pilot was operating the airplane under the provisions of 14 Code of Federal Regulations Part 91. The airplane sustained substantial damage; the airline transport pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed, and no flight plan was filed. The pilot reported that he had completed a cross-country flight to reenact the airmail route, and was part of a flight of two flying down the Columbia River. During the flight, the pilot had applied carburetor heat, but the engine lost power. He attempted to restart the engine, was unsuccessful, and then performed a forced-landing in a field. During the landing roll, the airplane collided with a tree and sustained substantial damage. The pilot reported that he purchased the engine and carburetor that were manufactured in about 1945, and when he purchased them, they were in new condition. Post accident examination of the carburetor showed that a piece of gasket material had entered into the main fuel jet. The gasket material was removed and the carburetor operated normally. Prior to installation of the carburetor onto the engine, it was inspected and bench tested by a maintenance facility. According to the facility, the carburetor tested within the specified limits and was installed on the accident airplane engine where it operated for 110 hours prior to the accident. The carburetor was not disassembled prior to the installation because it appeared to be in pristine condition. The facility indicated that in the future they will disassemble all older parts to check the components that might deteriorate over time.