DURING THE INITIAL GROUND RUN, THE RIGHT ENGINE SURGED, HOWEVER POWER WAS REGAINED AND THE TAKEOFF CONTINUED. DURING THE INITIAL CLIMB, THE RIGHT ENGINE SURGED AGAIN AND THE ELECTRIC FUEL BOOST PUMP WAS TURNED ON, BUT FUEL PRESSURE WOULD NOT STABILIZE. THE PILOT PERFORMED A PRECAUTIONARY LANDING. WHILE TAXIING A PASSENGER NOTED A FIRE IN THE RIGHT ENGINE. THE PILOT SHUT DOWN BOTH ENGINES WITH THE MIXTURES, OPENED THE DOOR, AND HE AND HIS TWO PASSENGERS EVACUATED THE AIRPLANE. THE ENGINE FIRE CONTINUED, EVEN THOUGH AIRPORT PERSONNEL AND A LOCAL FIRE DEPARTMENT APPLIED FIRE SUPPRESSANT. THE FIRE WAS EXTINGUISHED AFTER THE PILOT RETURNED TO THE AIRPLANE AND TURNED OFF THE MASTER SWITCH. SUBSEQUENT EXAMINATION OF THE AIRPLANE REVEALED THAT THE FLEXIBLE FUEL LINE BETWEEN THE MECHANICAL FUEL PUMP AND THROTTLE CONTROL BODY WAS LOOSE AT THE FUEL PUMP END.