Incident Overview
During takeoff, the aircraft's engine experienced a loss of power at approximately 300 feet above ground level (AGL). The pilot subsequently ditched the aircraft in a lake. After exiting the aircraft, the pilot entered a fishing boat that had pulled up alongside. Shortly after the ditching, the aircraft sank.
Engine Examination
Following recovery of the aircraft, the engine was prepared for a test run. Initial starting difficulties were encountered, but the engine eventually ran smoothly when the mixture was excessively leaned. The fuel control unit was then replaced, and with the new unit installed, the engine operated normally.
To further investigate, the original fuel control unit was reinstalled. Under this configuration, the engine again ran smoothly only when the mixture was leaned excessively. The original fuel control unit was subsequently bench tested. According to reports, the bench test results were normal, and after the bench test, the unit operated properly.
Conclusion
The cause of the engine power loss was not determined from the available information. No further details were provided.