As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ENGINE WAS NOT DEVELOPING POWER. UPON INSPECTION, FOUND THE CARBURETOR HEAT DOOR HAD BECOME LOOSE ON THE SHAFT GIVING NO CONTROL TO THE CARBURETOR HEAT. SUBMITTER STATED THIS WAS CAUSED BY CORROSION UNDER THE WELD THAT ATTACHES THE DOOR TO THE SHAFT. TO PREVENT THIS, THE DOOR SHOULD BE RIVETED TO THE SHAFT.