Our petcock fuel valve for 125cc, 200cc, & 250cc Hammerhead, Joyner, Kandi, & Taotao go-karts will also fit a wide range of other brands and models. The petcock valve is commonly found with go-kart, scooter, ATV, & dirt bike carburetors. The petcock is sometimes called a gas or fuel switch and it is a small valve that controls the flow of fuel from the tank to the carburetor.