I have the same exhaust as Speedee, however, I run it with the db killer, or street-legal baffle installed and have no problems. Not necessarily a large increase in power. It's a smoother running engine. And this exhaust weighs a lot less than oem. I mean a lot, like 10 or 12 pounds lighter. I also have a hi-flo air filter that I made using the stock filter box with Unifoam cut to size. Unifoam is used by motocross racers. No trouble with engine. Runs smooth and sweet.
Just returned from 870 mile tour, camping in the Davey Crockett National Forest. The piney woods of east Texas. Scooter performed like a dream, even when heavy loaded facing a stiff head wind that often veered to the port bow, ( left side of front).