As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PISTON PIN PLUG FAILURE DUE TO PISTON PIN MIGRATION FORCING THE PLUG TO THE BARREL WALL. UPON ZERO COMPRESSION CHECK, REMOVED CYLINDER AND PLUG WAS FOUND IN A SMALL BALL RIDING WITHIN THE PISTON PIN. BOTH COMPRESSION RINGS AND OIL CONTROL RING DAMAGED ALONG WITH CAM AND CAM FOLLOWER.