As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ENGINE RAN ROUGH ON FINAL APPROACH AND STOPPED ON ROLL OUT. ENGINE RESTARTED TO TAXI IN AND RAN VERY ROUGH AND BACKFIRED. EXHAUST VALVE ON CYLINDER NR 3 DID NOT MOVE WHEN ENGINE TURNED OVER. FOUND ROCKER AND SHAFT LOOSE IN ROCKER COVER.