All depends on how restricted they are. If you have those short turn out pipes then you will need to rejet. Most after market pipes , even the ones that say you don't need to rejet, you should re-jet. There is a jetting calculator on Dinquas web site you can download. You will find it in the tech vault. Jetting depends on many things,first is the levation you live and ride at, then is how restricted your exhaust is, then there is how restricted your intake / filtration is. Our bikes come lean from the factory so it is best to re-jet. once you get it close the best thing to do is take it to a dyno and have it run on there to get a reading of what your air fuel mixture is. The dyno sheet will tell you what you mixture is at a certain RPM so then you know where you need adjustments. ALWAYS MAKE 1 change at a time so you know what that change did. If you make more than 1 at a time you won't know for sure what one was good and what one was bad or if maybe both were bad.
