This is my first time posting here, and I was hoping to get some advice. I have a 91 XR, last year I had to replace alot of the top end. I had the work done and the mechanic put over sized rings in it, but it still smokes pretty good. Theres no doubt it could use a bore kit, but I want to try to do the work myself and send the cylinder away. But I don't know what options I have. If someone could give me an idea of what I'm up against, or point me in a good direction it would be much appreciated.