As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BOTH GEAR ASSYS (LEFT AND RIGHT) HAVE BROKEN TEETH AND CRACKS. THIS SITUATION CAUSED ENGINE TO QUIT OPERATING. THE ENGINE WITH THE MAG WAS INSTALLED ON 6-7-95 AND THE ENGINE QUIT OPERATING ON 9-16-95 WITH 334.8 HOURS SINCE OVERHAUL. ENGINE FAILURE OCCURRED ON ROLL-OUT FOR TAKEOFF. PRE-FLIGHT RUN-UP WAS SATISFACTORY WITH A 50 RPM DROP ON BOTH RIGHT AND LEFT MAGS. COWL DAMAGED BY ENGINE BACKFIRE. (X)