As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IN THE PROCESS OF COMPLYING WITH SB 71-3940/CSB08-9A/SB3-08A, IT WAS DISCOVERED THAT THE MAGNETO ROTOR CAM WAS WORN (.060 INCH COMPARED TO NEW). THE SPRING LOADED FOLLOWER ALSO INDICATED SOME WEAR TO THE EXTENT WHERE THE POINTS WERE BARELY OPENING. PILOT HAD REPORTED A LACK OF PERFORMANCE FROM THE ENGINE WHICH COULD ATTRIBUTED TO A COMBINATION OF WORN ROTOR CAM AND WORN DISTRIBUTOR BRUSH IAW BULLETIN.