As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) THE ENGINE DID NOT STOP AFTER THE MIXTURE CONTROL WAS CLOSED. THE ENGINE WAS STOPPED BY SHUTTING OFF THE MAGS. INSEPCTION FOUND THAT FOUR SCREWS THAT HOLD THE CARBURETOR HALVES TOGETHER WERE LOOSE AND ONE OF THE SCREWS WAS BROKEN. THE BROKEN SCREW WAS REMOVED AND REPLACED AND THE CARBURETOR WAS REASSEMBLED AND INSTALLED. THE ENGINE GROUND RUN SERVICEABLE AND THE AIRCRAFT WAS RETURNED TO SERVICE.