As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING ROUTINE INSPECTION, COULD NOT 'ROCK' PROPELLER. ENGINE WOULD NOT TURN BACKWARD EVEN WITH CONSIDERABLE TORQUE APPLIED. (600 FEET/POUNDS). AFTER REMOVING STARTER CLUTCH PN 643259A, ENGINE TURNED FREELY. IF ENGINE WERE TO KICK BACK DURING START, POSSIBLE SIGNIFICANT DAMAGE TO ENGINE COULD OCCUR.