Accident Details
While in cruise flight, the engine experienced a loss of power. The pilot performed a forced landing into a hayfield. During the landing rollout, the airplane nosed over after encountering a soft area of the field.
Pilot Actions
In response to the loss of engine power, the pilot stated he applied carburetor heat and selected a different fuel tank, with no effect on engine operation.
Engine Examination
An engine test run was performed, and the engine would not operate on the left magneto. The left magneto was disassembled, and the timing gear keeper was found laying loose in the case. The keeper, timing gear keyway slot, and magneto drive shaft were all worn. The timing gear and keeper were replaced with serviceable components, and the magneto was reinstalled on the engine. The engine operated on both magnetos, with acceptable engine rpm drops when selected on the individual magnetos.