What was found
WHILE ON CLIMB OUT, THE PILOT BEGAN TO FEEL A SLIGHT VIBRATION COMING FROM THE LT ENG. ELECTED TO RETURN TO THE AIRPORT WHERE HE MADE AN UNEVENTFUL LANDING. UPON INVESTIGATION, IT WAS NOTED THAT THERE WAS A SUBSTANTIAL RPM DROP DURING THE MAGNETO CHECK OF THE LT ENG`S LT MAG. THE MAG WAS REMOVED & DISASSEMBLED. INSPECTION REVEALED THAT THE BUSHING WITHIN THE DISTRIBUTOR BLOCK WAS EXTREMELY LOOSE. THIS CONDITION ALLOWED THE DISTRIBUTOR GEAR TO BECOME MISALIGNED WITH THE ROTATING MAGNET, JUMPING TEETH & CAUSING AN INTERNAL OUT OF TIME CONDITION. FURTHER INSPECTION REVEALED NO OTHER DISCREPANCIES. THE MAGNETO WAS ASSEMBLED WITH NEW PARTS & OPERATIONS CHECKED OK.