As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING A 100-HOUR INSPECTION, REMOVED MAG FOR IMPULSE COUPLING AD. FOUND SEVERAL TEETH MISSING FROM BOTH DISTRIBUTOR GEARS AND ONE GEAR CRACKED. ALSO NOTED LARGE CRACKS ON THE TOPS OF BOTH COILS. ENGINE AND MAG TIME SINCE FACTORY OVERHAUL 526.4 HOURS. CAUSE OF PROBLEM UNKNOWN. ON PRE-INSPECTION RUN-UP, MAG DROP 150/150.