As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORTED ROUGH ENGINE OPS AND HIGH EGT. INSPECTION REVEALED RIGHT MAGNETO CAMSHAFT FRACTURED AND SEPARATED BELOW CAM AT OUTER BUSHING. FRACTURED SURFACE DISPLAYED EVIDENCE OF PREVIOUS FRACTURE. SIXTY HOURS TIME SINCE NEW. AIRCRAFT TOTAL TIME: 2,202.9 HOURS. CORROSION WAS EVIDENT ON FRACTURE SURFACE. FAILURE OCCURED 8-29-97.