GY6 Engine Cooling Turbine Turbine compatible dimmer scooters equipped with a motor GY6 50 cm3 4 time. Dimensions: Outer diameter: 89 mm Inner diameter: 38 mm GY6 engine 139QMB 50 cm3 (49,9cc) 4 engine mounted on AJS, Adly, scooters Aeon, Baotian, Beeline, Branson, Daelim, Garelli, Goccia, Goes, Hp Power,