As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
OPENED MAGNETO DUE TO INABILITY TO SET TIMING TO ENGINE. FOUND CARBON ON CONTACTS. FOUND FACTORY DEFECT THAT COIL TAB WAS NOT INSTALLED PARALLEL WITH THE MAGNETO PARTING SURFACE PER SECTION 7.8C OF MANUAL L-1363J, RESULTING IN EXCESSIVE WEAR ON CARBON BRUSH (AND MOST LIKELY THE SOURCE OF CARBON ON THE CONTACTS).