As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CUSTOMER ATTEMPTED TO START ENGINE. WHILE CRANKING ENGINE, CUSTOMER REPORTED A LOUD "CLUNK" AND THE PROPELLER STOPPED ROTATING. INVESTIGATED PROBLEM AND FOUND THE STARTER DRIVE CASTING BROKE FROM STARTER MOTOR. THE CASTING INCLUDED A BEARING FOR THE STARTER DRIVE SHAFT. SHAFT AND BENDIX GEAR WAS STILL ATTACHED TO THE STARTER MOTOR. (K)