According to the pilot of the Piper J3L-65, he performed a preflight inspection and runup check of the engine without encountering any problems. He then ran the engine to warm it up, and afterward, taxied out to the runway. After another runup, he performed a high-speed taxi and all was normal. He then taxied back for takeoff, performed another runup, and took off. He then flew around the traffic pattern and landed. After taxiing back, he took off for a second time, the engine lost partial power, and the airplane struck trees while he was looking for an emergency landing area. According to a Federal Aviation Administration inspector, the pilot's most recent flight review was completed in December of 2003. The airplane had not flown since December of 2004, but had just received an annual inspection. Examination of the airplane revealed no evidence of any mechanical malfunction.