As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHEN REMOVING PLUGS FOR 100-HOUR INSPECTION, 2 PLUGS WERE FOUND WITH MELTED AND DEFORMED CENTER ELECTRODES. THERE WAS NO EVIDENCE OF FOREIGN MATTER INSIDE OF CYLINDER. THIS CONDITION WAS NOTED ON ANOTHER PLUG IN ANOTHER PLANE AS WELL. SPARKPLUG MFG BY AUBURN.