What was found
A 12 MONTH / 250 HOUR INSPECTION OF THE EXHAUST SYSTEM SLIP JOINTS AND MARMON CLAMPS, IS WAS NOTED THAT THE CROSSOVER EXHAUST TUBES COULD NOT BE SEPARATED. THE PIPES WERE ALSO DEFORMED. THIS IS A CRITICAL AREA OF THIS ENGINE INSTALLATION AND THIS INSPECTION IS REFERENCED IN LYCOMING 521 AND 531C.FAILURE TO PERFORM THIS INSPECTION AT LEAST ANNUALLY COULD LEAD TO EXHAUST PIPER FAILURE AND POSSIBLE FIRE IN THE ENGINE COMPARTMENT. WE REPLACED THE CROSSOVER PIPES P/N 40B19850 AND 40B19974 PER LYCOMING INSTRUCTIONS.