As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ENGINE WAS FOUND WITH A STICKING EXHAUST VALVE AT582.4 HOURS TOTAL TIME. LYCOMING SB388C WAS PERFORMED, ALL GUIDES WERE REAMED TO WITHIN TOLERANCE. THIS ENGINE INCORPORATES NI-RESIST VALVE GUIDES AND THE TIME TO FAILURE IS CONSIDERED BY THIS AGENCY TO BE PREMATURE.