On August 7, 2004, about 0900 eastern daylight time, a Cessna 150E, N6159T, was substantially damaged during a collision with trees, following an aborted landing at Marlboro Airport (9B1), Marlboro, Massachusetts. The certificated private pilot sustained minor injuries. Visual meteorological conditions prevailed for the flight that departed Marlboro Airport; destined for Fitchburg Municipal Airport, Fitchburg, Massachusetts. No flight plan was filed for the personal flight conducted under 14 CFR Part 91. The pilot stated that he departed from runway 32 at 9B1; a 1,659-foot-long, 45-foot-wide, asphalt runway. During the initial climb, about 1,000 feet agl, the engine began to run rough. The pilot initiated a 180-degree left turn toward runway 14, and reduced engine power to approximately 2,000 rpm. The pilot further stated that the engine vibrated less at the lower rpm setting. The airplane approached runway 14 "fast," and touched down within the first one-half of the runway. The airplane then bounced and floated past the midpoint of the runway. There was insufficient runway remaining to stop the airplane, and the pilot elected to abort the landing. However, during the initial climb from runway 14, the airplane struck trees and landed in a field off the departure end of the runway. During the landing, the nose gear collapsed and the airplane came to rest upright. Examination of the wreckage by a Federal Aviation Administration (FAA) inspector revealed that the number four cylinder exhaust valve was stuck in the closed position. The pilot reported that the most recent annual inspection was performed on the airplane on November 20, 2003. The airplane had accumulated 8 hours of operation since that inspection. The pilot reported 303 hours of total flight experience; of which, 170 hours were in the same make and model as the accident airplane. The pilot added that although he had practiced total loss of engine power procedures many times, he had never practiced partial loss of engine power procedures. Review of the FAA Practical Test Standards for a private pilot applicant revealed that "partial or complete power loss," and "engine roughness or overheat," were two items in which an applicant could be tested to analyze the situation and take appropriate action. However, an applicant was not required to be tested for those two items. The reported wind at an airport about 10 miles east of the accident site, at 0856, was from 340 degrees at 5 knots.