These match the airframe or engine model. Whether each one applies, and whether it's been complied with, depends on serial numbers, equipment and logbook entries. Applicability must be confirmed by a mechanic against the aircraft's records.
Airframe (152)Certain serial numbers: 150F 15061533–15064532; 150G 15064533–15064969; 150G 15064971–15067198; 150H 15067199–15069308; 150H 649; 150J 15069309–15071128; …. Only with: FA150L S/N FA1500121-FA1500261 and FA150M S/N FA1500262-FA1500336 only when equipped with FKA150-2311 and FKA150-2316.
EXHAUST VALVE IN CYLINDER NR 3 BROKE AT STEM, INGESTING INTO CYLINDER, CREATING A HOLE IN THE PISTON. PIECES OF VALVE AND PISTON ENTERED ENGINE, CONTAMINATING THE OIL. AN OFF AIRPORT LANDING WAS MADE WITHOUT INCIDENT. AFTER TEAR DOWN, THE CONNECTING ROD WAS FOUND BENT AND CRACKED.
From FAA Service Difficulty Reports; matched by N-number and serial number.