3-position OFF / ON / RESERVE A necessary item if your scooter lacks a fuel gauge This valve is commonly found on scooter, ATV, motorcycle, and dirt bike carburetors The is sometimes called a gas tank switch and it is a small valve that controls the flow of fuel from the tank to the carburetor 30 Day Warranty Description This valve is commonly found on scooter, ATV, motorcycle, and dirt bike carburetors. The is sometimes called a gas tank switch and it is a small valve that controls the flow of fuel from the tank to the carburetor. Our 3-position (OFF / ON / RESERVE) is especially useful on powersports equipment that lacks a fuel gauge. Many older motorcycles and scooters used a small auxiliary reserve tank instead of a gauge. If you needed to switch to RESERVE you knew it was time to fill up your regular tank. This is based on a common Yamaha design and it is a very useful scooter, ATV, dirt bike part that can be used on go-karts, dune buggies, and a wide range of gas-burning machines. Specifications Mounting Hole Center to Center Distance: 34 mm