As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE DOING AN ANNUAL INSPECTION ON AIRCRAFT ENGINE, MECHANIC NOTICED 2 LOOSE RIVETS HOLDING AIR BOX TOGETHER. REMOVED AIR BOX TO REPAIR AND NOTICED THAT CARBURETOR HEAT FLAPPER WAS HELD BY ONLY ONE RIVET. SUSPECT CAUSE AS IMPROPER RIGGING OF CARBURETOR HEAT CONTROL CABLE. SUBMITTER ALSO FINDS THAT IF BOX WAS NOT REMOVED FOR REPAIR, THE FLAPPER DAMAGE MIGHT HAVE GONE UNNOTICED.