[Water Warrior 2]

Leave the fuel in the "ON" position for normal operation. It is vacuum operated and shuts off fuel flow when the engine is shut off. You need only use the prime position after the bike has been parked for quite some time and fuel in the carb may have evaporated. Turn the fuel to prime for about 10 seconds to fill the float bowl in the carb then back to the "ON" position. 87 octane is the recommended fuel. There is no need to buy more expensive gas because you will not likely see any benefit. The GZ is a popular bike in the 3rd world where gas is sometimes 80% sticks and stones and the rest is noncombustable.