STOP PLEASE!!! I really don't understand why members on here have not told you to stop.
Don't remove the governor.
Don't lift up your wheel and spin your motor to make it explode.
Don't worry about a smaller sprocket and speed.
All you are going to do is end up hurting yourself or someone else will get hurt. If you put one of those cheap chinese engines on your bike, just leave it factory. In fact, reduce your speed until you get used to it. Put some miles down and get use to the way the bike rides. After you gain some experience riding, then you can consider going faster at a reasonable rate. Do you homework by searching threads on how to do it.
The most important part is to ride safely.