What was found
(CAN) CREW REPORTED THAT THEY HAD 3 UNCOMMANDED OVERSPEEDS OF RIGHT ENGINE N1 DURING FLT. 1ST 104.5 PERCENT N1 FOR 5.7 SEC ICAS N1 ICON TURNED RED. PILOT PULLED THROTTLE BACK & ENGINE DID NOT COME BACK FOR 3 TO 4 SEC. PILOT ADVANCED THROTTLE BACK TO CRUISE POWER & 2ND OVERSPEED HAPPENED. IT 103.3 PERCENT N1 FOR 6.1 SEC N1 ICON TURNED RED. THROTTLE PULLED BACK & WITH 2 TO 3 2ND DELAY BEFORE ENGINE CAME BACK IN SPEED. N1 SPEED SWITCH TURNED OFF&ENGINE SPEED ADVANCED BACK TO CRUISE POWER. 3RD OVERSPEED THEN HAPPENED AT 99.1 PERCENT FOR 0.7 SEC. PILOT REDUCED THROTTLE & TURNED A/C BACK TO DEPTR AIRPORT.MAIN FUEL CNTL REPLACED & A/C RT-SRV.2001-05-11 TC: INVESTIGATING