Take your engine and hub like ralph sugested to ace hardware,or any similier and open all the drawers that have woodruff keys in them until you find one that fits the grove in crank.If the hub doesnt go on youll have to grind off the top of the key a little to make it fit.Actually,if the hub has the taper,just put a little locktite on the taper and tighten down,after its dry it wont move.Its the taper that holds it tight.The keyway is just for people at factories to have somthing to line the magnets up with tdc.Once i used a flat washer and put it in vise and cut off the corner so it was halfmoon shaped.Fit my sachs engine perfect.