I have searched the pages looking for answers. I am thinking of trading my YFZ450 for a YZ450F. After having double knee surgery, I can't get all wadded up to ride the YFZ I just built and never got to ride. Some of the perks of getting old. Then again, I don't need ramps to load my stuff either. You all know the ins and outs of the years and the beast, teach me o great OB1. What years do I want and why? Injection pros and cons?? This will mostly be a fence checker and an occasional flogging will be in order. Too old for the MX tracks and there is one just south of me about 10 miles. I love this site, so much help and great people.