Purchased an '03 WR450 a few weeks ago. After reading all the woodruff key posts I contacted my dealer, he replied right away and said that his rep did confirm the woodruff key problem but that my bike was built after the problem had been corrected at the factory. I do believe the new idler gear may be a wise investment though. Anyway, been riding a Husaberg FE600 the past two years. I must say that the WR feels peppier however, it does not hook up like the 'Berg. Still getting used to it and tuning the suspension. Only mods so far was removing the plug. I was extremely disappointed after the first ride with the plug in, could'nt believe the difference after removing it. I will continue to modify as I see fit. Plan to ride HS this next season, really like the tight stuff and I think the WR will work for me. I have learned alot from this site and am sure I will learn more and maybe even contribute something useful.