1991 500e gas tank has no pet cock valve!!! I can run the engine with the carb bowls full but when the fuel tank volume releases fuel the carbs spill out the throat!!1 the weight of the fuel is critical I believe to supply the carbs which have new needles and seats floats are clean! engineers have designed the bike wit a main fuel valve and reserve so I assume I need to purchase the gas tank required valves for proper flow!!!!