What was found
ENGINE RAN ROUGH WHEN ON AFFECTED MAGNETO ONLY. DURING RUNUP FOR ROUTINE SCHEDULED INSPECTION. ON DISASSEMBLY OF MAGNETO, DISCOVERED THE DISTRIBUTOR FINGER HAD DISLODGE FROM THE DISTRIBUTOR GEAR, CAUSING ERRATIC TIMING. HAVE SEEN THESE FINGERS COME SLIGHTLY LOOSE IN THERE MOUNTING BEFORE, BUT NEVER JUST COMPLETELY LOOSE, READY TO FALL OUT.