As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING RIGHT ENGINE START, STARTER SWITCH DID NOT RETURN TO AUTO POSITION. AIRCRAFT RETURNED TO BLOCK. *S/D* THE SELF LOCKING NUT RETAINING THE MAGNETIC ROTOR FOR THE N2 INDICATING SYSTEM BACKED OFF OF THE THREADED DRIVE SHAFT. SIGNAL WAS LOST DUE TO DISENGAGED MAGNETIC ROTOR. RESECURED THE MAGNETIC ROTOR WITH A NEW SELF LOCKING NUT AND KEY WASHER.