| I have never understood why there needs to be any water in the overflow tank. The radiator cap is sprung loaded to 1.1 or 1.2 bar, depending on the age of the bike, and will therefore only allow water to pass in one direction. The overflow tank is what it says, an overflow, and there is no way for the water to get back into the engine. I have always kept the tank empty and no water has ever appeared. |