Lately, there have been a bunch of "what do I do first" posts, by new bike owners. This is my list of what I do to every new sport bike, in the order that I do it, as my finances allow..........

1st. Things that enhance the durability and safety of the machine.
Full Chassis and Swingarm Skids (DG Baja), Nerf Bars (DG), Bumper (DG), Rims and Tires (ITP Holeshots on Baja Rims), Handlebars (Tag Metals).

2nd. Only after I have done the above, do I move on to the engine. For reliability (life-and-death in the desert!), I don't mess with the engine internally!
K&N with Outerwears, Vented Airbox Lid (http://www.ehsracing.com/), FMF PowerBomb Header and Muffler (Factory 4). And of course a rejet. Chain and Sprockets.

3rd. This is the really expensive stuff!
Aftermarket Suspension, A-Arms, Axle, etc......