I tried a search, with no help.... My brother-in-law smoked the piston on his 1999 YZF400. Needless to say, he needs a replacement cylinder, or recoat the old one. We are thinking about making the displacement larger so he can beat a few more 450's. Most of the bigger bikes are behind him, but second or third place just isn't good enough for him. I heard that it's possible to install a YZF426 cylinder on a 400 and make it a 440. Is this even possible? Any mods such as machining, spacer, etc? Any links to threads, web sites, or anything you can offer would be appreciated.