build up.. rather just redo the packing if you want in the pipe but nothing else really to worry about if its clean looking. it will sometimes sound a little better and perform better after some useage
how much use... is it clean atleast? if so don't worry about it. just don't pay a new exhaust price for a used one.
I'm with Gimpsta. 04/05 should not have to much usage on it, but some miles do break in the sound. Vrooom vroooom. :biggrin
Cost is much better as well. I current have a used pipe on my bike. Can beat the price. You can get a bolt on for $150 or less on Ebay.
the good thing about ethanol blended fuel, is that it burns cleaner, and will clean out all the shit built up in your combustion chambers and exhaust, i say get it So carbon build up wont be too much of a problem after a few tanks:cheers
sound however may be affected if the packing is trashed. but i would highly doubt that based on the year of the bike, and if it is, you can get it repacked