I too agree that loud pipes are annoying to the 99% ers I removed my end cap and got an increase in speed of about 8 miles an hour, and the thing would pull a wheely if i reved it and let out the clutch, yea I know thats not good for the chinese pucks, but man what a difference in power. So as not to annoy people,I tried something different. I cut off about 2 inches of that little pipe that is welded to the end cap. The power is night and day worked great and bike is still quiet, has just a slightly deeper rumble. Oh yea I purchased a no name motor from E-bay store Luckyearlybird and man besides the cheap studs, this is the best motor yet a 66cc Have fun