Well if you are only going to add pipes then i would say you donĀ“t neccessarily need to rejet the carb it will run and it will probably even run better. But you should at the very least adjust the AIR to FUEL mixture you need to get you an owners tech manual and read up on the adjustment of the carburator it is really quite simple so learn how to do it and stop paying money to the DEALER STEALER. If you plan on adding a heavy breathing air filter then you will probably need to rejet but with just pipes you wont need to.