THE PILOT OF A SIGHTSEEING FLIGHT REPORTEDLY DEPARTED THE AIRPORT WITH THE RIGHT FUEL TANK SELECTED AND ONE HOUR OF FUEL ENDURANCE IN THE TANK. APPROXIMATELY 45 MINUTES LATER, THE ENGINE LOST POWER WITHOUT WARNING. THE PILOT SWITCHED TO THE LEFT FUEL TANK BUT DID NOT USE THE FUEL BOOST PUMP AS DIRECTED BY THE AIRPLANE CHECKLIST. NO PROBLEMS WERE FOUND WITH THE ENGINE DURING POST ACCIDENT INSPECTIONS PERFORMED BY LICENSED MECHANICS.