What was found
(CAN) DURING AIRCRAFT START-UP THE PILOT TRIED TO MOVE THE MIXTURE KNOB FROM IDLE CUT-OFF TO FULL RICH AND THE CABLE WOULD ALWAYS SPRING BACK TO THE LEAN POSITION. AIRCRAFT WAS BOUGHT IN FOR INSPECTION AND THE SNAG WAS CONFIRMED, THERE WAS A SIGNIFICANT AMOUNT OF RESISTANCE THAT WOULD ALLOW THE CABLE TO STRETCH THE OUTER SLEEVE AND ACT AS A SPRING. THE CABLE WAS REMOVED AND NEW CABLE WAS INSTALLED. MFC ADDED A MANDATORY REPLACEMENT TO THE CABLES AT 2200HRS WITH A 200HR EXTENSION DUE TO THE PREVIOUS HISTORY OF THE ENGINE CONTROLS.