I have a 99 warrior with a DG pipe and a KN air filter. I was thinking about changing the sprockets but don't know anything about what size to get. I want it to have better low and mid range power without losing much top end. Can anyone please help?

 

Assuming you're running the stock sized tires, the inexpensive way would be to drop one tooth on the c/s sprocket to a 12T. This will give you more low & mid range but at the expense of top end. The other way to shorten the gearing would be to buy another rear sprocket a couple of teeth larger.