Incident Overview
A pilot experienced a partial loss of engine power while returning from Marathon to Venice. The pilot switched fuel tanks, but the power loss persisted. After notifying Fort Myers Approach Control of the problem, the engine power deteriorated to 1,600 RPM. The pilot then elected to ditch the aircraft in Chorolosoe Bay, approximately 200 yards offshore, in about 3 feet of water.
Investigation Findings
Following recovery of the aircraft from the bay, an engine teardown was performed. Examination revealed that the number one cylinder intake valve was tuliped. Both the cylinder and the top of the piston were clean, indicating that a loss of compression and detonation had occurred in that cylinder. These conditions explained the partial loss of power experienced by the pilot.
Conclusion
The investigation identified that the partial power loss was due to a tuliped intake valve on the number one cylinder, resulting in loss of compression and detonation.