What was found
(CAN) DURING START SEQUENCE, NR 2 ENGINE FAILED TO ROTATE, START SEQUENCE WAS CANCELLED, AND TRIED A SECOND TIME WITH NO ROTATION OF ENGINE. FAULT WAS TRACED TO THE STARTER GENERATOR, UNIT WAS REPLACED WITH A NEW AND START SEQUENCE WAS OK. NR 2 ENGINE STARTED AS PER MM. THIS IS THE SECOND STARTER GENERATOR FAILURE, THE OTHER HAPPENED 100 HOURS AGO ON NR 3 ENGINE. INSTALLED UPGRADED STARTER/GENERATOR [/N 8060-150. FALCON JET IS AWARE OF THIS PROBLEM. THE NR 1 ENGINE STARTER GEN AND APU STARTER GEN ARE GOING TO BE UPGRADED TO -150.