This Magneto Cylinder / Stator Housing is the most common design used for GY6 50cc ATVs, dirt bikes scooters etc. CFW50      Inner Diameter (ID): 89.9mm    Outer Diameter (OD): 109.3mm    Overall Height: 37.2mm    Center Hole Mount (Tapered): 10/14mm    Mounting Holes (center - center) (Side by Side): 72mm    Threaded Holes: 5mm