As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ENGINE S/N L-359141-51E WAS FOUND STICKING EXHAUST VALVE AT 381.8 TOTAL TIME. LYCOMING SB388C WAS THEN COMPLIED WITH, AND DURING THE WOBBLE CHECK, NR 2 WAS ACTUALLY STUCK. ALL THE GUIDES WERE THEN REAMED TO WITHIN TOLERANCE. THIS ENGINE INCORPORATES NI-RESIST VALVE GUIDES AND THE TIME TO FAILURE IS CONSIDERED BY THIS AGENCY TO BE PREMATURE.