sprocket mounting/machining help!!!

I am finally starting to assemble this pile of parts into a motorbike, but....the sprocket doesn't fit over the hub. Should I have the center hole in the sprocket machined out larger? I am not a machinist, so I have to pay a shop to do this. Is there another (cheaper) alternative? And, when I call a machine shop to get an estimate, what do I ask for? Just tell them that I need a larger hole in my sprocket? If anyone else has had this done, can you give me some idea of what this costs? Of course prices vary by region, but I just wanted to make sure I wasn't getting raped when I get a price quote. On the upside, I think that building a front motor mount out of a 2.25 muffler clamp, fuel line and assorted bolts, nuts & washers is going well, lol. Thanks for any advice.

Ride Safe!

Gonzo

Alternate plan B - after calling a few machine shops & Vantics, it will be a lot cheaper to get a new rear wheel!

Ride Safe

Gonzo

I was talking to a friend of mine earlier and he said "remember when you put that new crank pulley on my bug?" The pulley was just that much too small, so I opened it up a little with a dremel tool. I guess I am not thinking too clearly. (big news, lol)