As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FUEL PRIMER LOCKING RING NUT WAS MISSING APPROXIMATELY 180 DEGREES OF MATERIAL. THIS PREVENTED THE PLUNGER FROM LOCKING IN. THE NORMAL LOCKING AREA IS THE WIDTH OF THE PIN ON THE PLUNGER, THE AMOUNT OF LOCK MISSING WAS APPROXIMATELY 10 TIMES THE WIDTH OF THE PIN.