What happened
The pilot reported that he had been experiencing difficulty obtaining adequate takeoff power from the engine. To compensate for this issue, he had been running the engine at high RPMs to burn out deposits before each flight. During the incident takeoff attempt, the engine loaded up and failed to produce enough power to maintain controlled flight. The aircraft was unable to climb and subsequently impacted an adjacent field.
The investigation
The source text does not provide details on a mechanical inspection or post-accident examination of the airframe or engine components. It notes that a top overhaul was scheduled to be performed two days after the accident, indicating maintenance was planned but had not yet occurred at the time of the event.
Findings
The primary factor contributing to the incident was the engine's inability to develop sufficient power during the takeoff phase. The pilot's prior experience of needing to burn out the engine suggests a pre-existing performance degradation that was not resolved before the flight.