What was found
REPLACED PARTS RECEIVED BACK FROM OVERHAUL AGENCY FOLLOWING PROP STRIKE DISASSEMBLY INSPECTIONS INCLUDED A PN SL-10204J PISTON AND SUBJECT NR 3 CYL. INTAKE PIPE. PISTON EXHIBITED EARLY STAGES OF TYPICAL DETONATION DAMAGE ON THE HEAD, ADJACENT TO ITS O.D. AT THE 12 O'CLOCK POSITION AS INSTALLED. TPT 678 HRS. CAUSE APPARENTLY DUE TO EXCESSIVELY LEAN MIXTURES RESULTING FROM AMBIENT AIR ENTERING SUBJECT CRACKED INTAKE PIPE ADJACENT TO ITS CYLINDER-MATING END.