As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WITH TAKEOFF POWER ON LATIER RALE OF TAKEOFF & CLIMB OUT STROAS BURNING RUBBER SMELL FILLED THE CABIN. FA RETRACED SMELL TO COMPORT 3 TO 4 MINUTES, AFTER CLIMB POWER SELECTED BURNING RUBBER SMELL DISSIPATED. R & R LT PRESS REGULATOR VLV IAW AMM 21-31-01-2. OPERATIONS CHECKED GOOD.