Accident Overview
A pilot performed an engine runup before commencing takeoff on runway 17. According to a witness, the airplane used approximately 2,000 feet of runway to become airborne. Another witness observed the departure and reported that it appeared to be underpowered and slow. A third witness reported that the plane passed overhead and the engine sputtered. The witness further observed the plane bank up and to the east, the engine sputtered twice again, and the plane stalled out, spiraling down into the water.
Engine Examination
An examination of the engine revealed that the number one cylinder exhaust valve was stuck in the open position due to carbon buildup on the valve guide.
Probable Cause
The stuck exhaust valve in the number one cylinder, caused by carbon buildup on the valve guide, resulted in a loss of engine power.