What was found
(CAN) ON CLIMB OUT AFTER TAKEOFF, THE PILOT NOTICED MILD TO MODERATE ENGINE VIBRATION WITH A PARTIAL LOSS OF POWER. A RETURN TO THE AIRSTRIP WAS CARRIED OUT WITH A SUCCESSFUL LANDING. ON INVESTIGATION BY AN AME, THE PROBLEM WAS NOTICED AS AN EXHAUST VALVE STUCK OPEN ON THE NR 3 CYLINDER. THE CYLINDER WAS REMOVED AND WAS SENT TO AN ENGINE OVERHAUL SHOP FOR REPAIRS. THE CYLINDER IS STILL BEING REPAIRED AND WILL BE REINSTALLED UPON RETURN FROM THE SHOP. (TC NR 20070910006)