As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TWO NEW SNAP-RING COUPLINGS INSTALLED AT ANNUAL INSPECTION. SEVEN HOURS LATER BOTH COUPLING SPRINGS FAILED ON CONSECUTIVE ENGINE STARTS. SPRING FAILURES APPEAR TO BE IDENTICAL. COUPLINGS WERE BOUGHT AND INSTALLED AS ASSEMBLIES PREVENTING INSPECTION OF SPRINGS PRIOR TO INSTALLATION.