The belt sprocket is powdered metal, not a cast or machined piece, and is just metal dust that's been squdged together and doesn't have any real tensile strength, so using a puller that uses tapped holes, a la a chevy steering wheel puller or harmonic balancer puller is iffy, and the part is compromised (a paper weight) anyway after you get it off. Just dremel a slot in the sprocket, and drive in a wedge, and the two parts come off quite easily. Then you can dress up the crank nose with fine emery paper, and use antiseize so it comes off easy next time.