With this bike, you can run full exhaust no probs (just block off the AIS plates.) It runs super rich from factory. I have full exhaust, and have no problems, but I have also blocked off the AIS. Taking the stock muffler off doesn't even make the bike noticeably louder because of the car muffler under the bike. You can 100% take that stock muffler off without doing anything else to the bike.