As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING A ROUTINE 500 HOUR INSPECTION OF THE MAGNETO, SMALL CRACKS (1/4 INCH OR SHORTER) WERE FOUND IN THE ROTOR HOUSING WHERE THE MAGNET PROTRUDES THROUGH. TECH REP WAS CONTACTED AND WE WERE ADVISED THAT ALTHOUGH NOT COMMON, THIS WAS NOT RARE AND IS COMMON TO THE O-540 ENGINE SERIES AND PREDOMINENTLY TO THE O-540 INSTALLED IN R44 AIRCRAFT.