As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING T/O ROLL, RT N1 ROLLED BACK FROM 90.8 (T/O PWR SETTING) TO 80 PERCENT N1. REMOVED AND REPLACED BOU TORQUE MOTOR BASE GASKET IAW MM 75-30-01 C/W RUNS ALL CHECKS GOOD LEAK CHECKS GOOD. DOWN LOADED EFC AND NOTED NO TR FAULTS. FOUND FAULT FI09 AND ALSO FOUND TORQUE MOTOR GASKET BLOWN OUT, CONTACTED MFG, THEY SUSPECT GASKET CAUSED ROLL BACK. POWERS CHECKED GOOD IN AUTO AND MANUAL.