As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DISCREPANCY: #4 ENGINE SHUT DOWN DUE TO CARBURETOR HEAT APPROACHING RED LINE AFTER GOING INTO REVERSE.CORRECTIVE ACTION: INSPECTED CARBURETOR INTAKE FOR FOREIGN OBJECTS, NONE FOUND. INSPECTED AIR DOOR FOR SECURITY, FOUND SECURE. RAN ENGINE TO 30" AND A REVERSE CHECK, ALL PARAMETERS FOUND OK. SUSPECT ICING CONDITION WAS THE FAULT.