I've found several decent looking cylinders on ebay that were usable, cylinder plus new piston and rings will run 300-400 dollars after having the cylinder finish honed. I did a big bore kit on mine for around 700.00 dollars, this was done by CE Enterprises. If you decide to go that route there are other kits available, but I liked CE's deck modification as I've heard others have had head gasket issues. If serious about a big bore look at CE's web site. I've attached pictures of the top of the cylinder, and you will notice a big difference over stock! It provides much greater gasket surface! I love my big bore kit, it really woke mine up. I also added a Web Cam, Speedwerx Valve springs, a digital fuel controller, and a looney Tunes Exhaust.