Petcock - Fuel Valve, Gas Valve, Long Stem. This is commonly (but not exclusively) used for 50cc, 70cc, 90cc, 110cc, 125cc, 150cc, 200cc and 250cc ATVs, buggies, go-karts and other powersports or motorized products. Widely used for Eton 50cc Viper, Eton 90cc Viper, Eton 125cc Viper (including the models sold at Canadian Tire). Outer nut diameter approximately 22mm and inner maximum thread diameter approximately 14.5mm.