On February 7, 1998, about 1530 eastern standard time, a Boeing A75L300, a Stearman, N55412, was substantially damaged when it struck trees during a forced landing near the Orange Poultry Farm Airport (4NY1), Chester, New York. The certificated commercial pilot and passenger were not injured. Visual meteorological conditions prevailed for the personal flight which originated at Warwick, New York, destined for 4NY1. The flight was conducted under 14 CFR Part 91. According to a Federal Aviation Administration Inspector (FAA), the airplane had a supplemental type certificate for the use of automotive gasoline, and the pilot used a 55 gallon drum with a pump and filter to refuel the airplane. Earlier in the day, the pilot had added 10 to 15 gallons of fuel to the airplane from the drum. The pilot then departed Warwick with a passenger for the 4 mile flight to 4NY1. Upon arriving at 4NY1, the pilot circled in the pattern to alert persons on the ground of his intention to land. During the pilot's second circle in the pattern, while on downwind at 500-800 feet (AGL), the engine lost total power, and the pilot performed a forced landing to a wooded area. Examination of the wreckage was performed by an FAA Inspector, who stated that when fuel was drained from the gascolater into a 6 inch diameter glass jar, 1 1/2 inches of water was present at the bottom of the jar. Additionally, unidentified particles were found suspended in the fuel, throughout the sample. In an interview with an FAA Inspector, the pilot said he drained the gascolater before adding fuel to the airplane from the drum. However, he did not drain the gascolater after the fuel was added to the airplane. After the accident, all the fuel was drained from the engine and the engine was refueled. An engine run-up was performed by the FAA Inspector, and the engine performed satisfactorily.