Electric choke 18mm Carburetor most commonly used for (and not limited to) 50cc GY6 style engines. Also used for some 2-stroke 49cc, 4-stroke 49cc, 50cc, 70cc and 90cc scooters (direct replacement carburetor for the 49cc/50cc Benelli scooters for example) and smaller 4-stroke automatic ATVs and go karts / buggies.