Has anyone else tried this. I noticed that the 03 starter gear has a roller bearing and spacer that holds it in place, and the 04 has a brass bushing (like the clutch hub) and seems to float. Spent hours tring to figure out what is missing or changed. All parts from cam chain gear to the end of the crank are 04 parts. I have been all over Yamaha's parts catalogs and there is nothing between the starter gear and the cam chain guide (on the bottom of the rear cam chain slider). 2004 starter works much better and I know I won't have a key problem. If you have a 2004 WR450 and been behind the rotor, do you remember if the starter gear "floats"? Thanks for any help.