What was found
(CAN) 35 MINUTES INTO FLIGHT AT ALTITUDE 290, WITH APU OFF, COCKPIT CREW SMELLED FUEL IN THE COCKPIT. CLOSED GASPERS AND DONNED OXYGEN MASKS. F/A DID NOT SMELL FUEL IN THE CABIN. CONTINUED ON AND COMPLETED FLIGHT. MX TIGHTENED B-NUT AT APU FUEL CONTROL AND SHUTOFF VALVE. CLEANED RESIDUAL FUEL AND RAN PACK FOR AN HOUR, NO ODOR NOTICED OK FOR RTS. SERVICED O2, DEFERRED NAV LIGHT.