What was found
ON 1/16/26 AT APPROX 2030Z 2NM NE OF THE LAKE MURRAY DAM, ON A FLT FROM KCUB - KEOE AT 2000' MSL, ENGINE BEGAN EXPERIENCING SEVERE VIBRATION & RPM LOSS. ENG BEGAN SPUTTERING & SHUT OFF. MIXTURE WAS FULLY ENRICHED & THROTTLE MOVED TO THE FULL POSITION, ENG THEN BEGAN TO SPUTTER AGAIN & ABLE TO MAINTAIN 1500 RPM. THE SAME CYCLE REPEATED. ACFT WAS ABLE TO MAKE AN EMER LANDING AT KCAE. ON DISASSEMBLY & INSP OF ENG, FOUND CYLINDER 2 EXHAUST VALVE SPRING RETAINER BROKEN IN HALF ALLOWING EXHAUST VALVE TO DROP INTO CYLINDER 2 CAUSING CATASTROPHIC ENG DAMAGE. CYLINDER WAS A RELATIVELY NEW CYLINDER ASSY HAD APPROX 37 HOURS ON IT SINCE NEW.