MC^MP 420 13-Tooth 17mm Engine Sprocket for 50cc 70cc 90cc 110cc 125cc ATV Dirt Bike Go Kart Go-karts Pit Bike 4 Wheeler 420 chain 13-Tooth 17mm Engine Sprocket fits for 50cc-125cc ATV, Dirt Bike,Go Kart fits for 50cc-125cc Horizontal Engine inside diameter:17mm