As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD - FLT 1641 - EN ROUTE ORD-SAT, SMELLED SMOKE THROUGHOUT AIRPLANE ON TAKEOFF ROLL, CREW THOUGHT IT WAS FROM AIRPLANE CLOSE TO THEM THAT WAS IN FRONT. FUMES GOT STRONGER AND RMDFU ALERTED 'SMOKE AFT RIGHT TOILET'. RETURNED ORD AND LANDED WITHOUT INCIDENT. REPLACED NR 2 ENGINE STARTER PER MM. SYSTEM GROUND CHECKED NORMAL OPERATION. NO ODOR OR SMOKE IN CABIN. (M)