Okay, Here is a fun one... I'm ready to get more out of my bike. It's a 2005 WR 450 and it's not had anything done to it. It's pretty stock. The shop I bought it at said that he had done all the free mods (throttle stop, air box, etc...) although, nothing was done to the exhaust. What are the best things I can do to get more power out of my bike, and how much of a difference will each change make?