Theres a guy on ebay that sells ignitions boxes for them. I tried 2 before I gave up. The first never did work, and the second would work for 20 minutes or so before it overheated and started misfiring. But it really helped to wake the 450 up considerably. I had already went down to a 12T countersprocket and a PC Ti-4 and taken the airscreen out but it was still doggy felling when you pinned it. Maybe he has sorted out the problem and they are reliable now. For a second comparison, my kid is 16 and has been riding a yz250f for 2 years now. I let him try it out this past weekend since I decided to go ahead and take it back out of mothballs and ride it for a while. His comment was, jeez this thing is slow. Even kids can tell.