Incident Overview
During cruise at an altitude of 9,000 feet MSL in instrument meteorological conditions (IMC), the pilot experienced an engine misfire followed by a complete loss of power. Air traffic control provided a vector to the nearest airport, but the pilot was unable to reach a runway and subsequently performed a forced landing in a soft field.
Post-Incident Examination
A post-incident examination of the engine found no internal mechanical anomalies. However, inspection of the carburetor revealed several issues contributing to a rich fuel/air mixture. Specifically, the carburetor float was set high (rich position), and both the throttle shaft O-ring and the accelerator pump rod screw were leaking.
Contributing Factors
The combination of the incorrectly set float and the leaks in the throttle shaft O-ring and accelerator pump rod screw contributed to an excessively rich fuel/air mixture, which likely led to the engine power loss.