I am getting ready to purchase a 1996 cylinder for my 1989 XR600. I had a thought that what if the cylinder on my 89 had been replaced in the last 17 years of the bikes life. The reason I was buying a new one is because the cylinder is out of spec, and I assumed the cylinder was the original nikasil plated and couldn't be bored to the next oversized piston. So I wanted to make sure that I indeed have a nikasil plated cylinder (not a replacement steel one). How can I tell by looking at the cylinder? Also, why can't a nikasil plated cylinder be bored? Is it because the plating is to hard. I would think I could just bore out my cylinder and run an oversized piston. But I really have no idea of how the nikasil cylinders are built. Thanks.