Shortly after the aircraft took off from Stellar Airpark, several witnesses saw it flying northbound with smoke trailing from the left engine. One witness, a student pilot, stated that the gear was down and the plane was lower than normal, about 500 ft AGL. Another witness, an airline captain, stated that the left engine was "pulled back" and wind milling. At first he thought it was on a training flight. The aircraft was then observed to start a right turn, then roll to the left, crashed and burned about 1.3 mi north of the approach end of runway 17. A disassembly inspection of the left engine revealed damage to the #5 piston and cylinder. A hole had burned through the top forward edge of the piston and extended below the oil control ring. The top compression ring was fractured and the cylinder wall was scored. Also, the piston dome was deformed and cracked. Small metal particles were found in the oil filter element. The engine was otherwise unremarkable. Estimated aprx 100 lbs over max wt limit.