Incident Overview
After takeoff, the airplane's engine began to sputter at an altitude of approximately 200 feet above ground level (agl). The pilot's corrective action did not resolve the problem. He elected to land in trees rather than straight ahead to avoid striking wires.
Pilot's Account
The pilot reported that the airplane had not flown for a week. During the preflight inspection, he drained the fuel tanks and noted "some very small bits of junk (about 3-4 < pin head size)" in the right fuel tank, which contained 87 octane fuel. He drained about 1 1/2 pints until the fuel ran clear. The engine was started on the left tank, which was full of 100LL fuel. The right tank was observed to be about one-quarter full.
FAA Inspector's Findings
An FAA inspector examined the wreckage and concluded that, after reviewing the aircraft records and having an extensive conversation with the pilot, it appeared that the aircraft suffered some fuel contamination, considering that the aircraft had been stored for a while.
Conclusion
The investigation identified fuel contamination as likely cause, without further details.