What happened
The pilot reported conducting a normal takeoff with the engine operating at 2200 RPM. Shortly after the aircraft rotated for climb, the engine RPM began to decrease significantly. Consequently, the aircraft lost altitude and impacted the top of a large oak tree.
The investigation
A physical examination of the aircraft revealed that the carburetor inlet finger screen was obstructed. Specifically, the screen had a 75% blockage caused by uncured fuel tank sealant. This obstruction restricted the flow of fuel to the engine.
Findings
The restriction in fuel flow resulted in a subsequent loss of power during the critical takeoff phase. The pilot was unable to maintain altitude following the rotation, leading to the collision with the tree.