As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CARBURETOR HALVES ARE BECOMING LOOSE DUE TO THE IMPROPER INSTALLATION OF THE LOCKTAB WASHERS AT OVERHAUL. THE LOCKTABS ARE BENT DOWN ON THE "TIGHTEN" SIDE OF THE CORNERS OF THE CARBURETOR WHICH ALLOWS THE BOLTS TO LOOSEN APPROX .2500 TURN WITHOUT DISTURBING THE LOCKTAB RETAINERS. THIS IS IDENTIFIED BY VISUAL INSPECTION OR POOR, ERRATIC IDLING, INCREASED IDLE RPM, OR INCOMPLETE ENGINE SHUTDOWN WITH MIXTURE CONTROL.