What was found
(CAN) FLIGHT CREW REPORTED THAT THE RIGHT HAND ENGINE WOULD INTERMITTENTLY 'SHUDDER'. THE FLIGHT CREW SECURED THE ENGINE AND THE AIRCRAFT RETURNED TO BASE UNEVENTFULLY. A DETAILED INSPECTION OF THE ENGINE AND IGNITION SYSTEM REVEALED THAT THE STARTING VIBRATOR WAS INTERMITTENTLY ACTIVATING. ACTIVATION OF THE STARTER VIBRATOR GROUNDS THE PRIMARY POINTS IN THE MAGNETOS AND UTILIZES THE SECONDARY POINTS IN THE LEFT HAND MAGNETO TO ADVANCE THE TIMING FOR STARTING. THERE HAVE BEEN NO FURTHER REPORTED INSTANCES OF MALFUNCTION SINCE THE STARTING VIBRATOR WAS REPLACED.