As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMBOUT AT APPROX FL 250 PILOTS NOTICED ODOR IN COCKPIT. THE ODOR BECAME STRONGER, SEVERAL MINUTES LATER THE RT GEN OFF LIGHT ILLUMINATED WITH ASSOCIATED EICAS LIGHTS. THE INTENSITY OF ODOR REQUIRED USE OF COCKPIT OXYGEN MASKS. A/C DIVERTED TO JAX. REPLACED GCU, IDG AND PYLON DISCONNECTS D4216P AND D4266J. RAN ENGINE, SYSTEM CHECKS NORMAL.