Re: another newbie
I think what you are asking is if there are gears on the motor. the answer is no. you can buy a shift kit from sickbikeparts.com but it's expensive. the internal gear ratio of the engine is 4.41:1. with a 44 tooth sprocket on the wheel (4.4:1) you get a final gear ratio of 19:1. If you get a smaller sprocket you will go faster but sacrafice acceleration.
as far as the muffler, you can get something called a Poo-Poo pipe. I think Spookytoothcycles.com sells them. you can also buy an tuned exhaust. Sickbikeparts.com sells a really nice one.