Bear with me, I'm new with chain drives. I think I need a new sproket, the teeth are sharp and I've been told that means it is worn out. I've heard that you can get sprokets with different #'s of teeth, but I don't know if I would want a sproket with more or less teeth than stock. I assume that it would change my top speed. Also I have 20x11x9 rear tires, I think the stock ones are 22, so how does that effect my top speed and take off?? I do mostly trail riding, some feilds and jumps, so what should I do about an aftermarket sproket?? More or less teeth, or keep stock #??

 

The smaller the rear tire, the higher the gear ratio. You will lose top end speed with the smaller tires, but you will get there quicker. Putting a sprocket on with more teeth will lower the gear ratio, which means more top end speed and less snap down low.

 

dondiesel8,
You failed to say what your ride is, but generally, if you run 2" lower tires than stock, you can gain back the stock gearing by changing your c/s sprocket (notice how the word is spelled)
to one tooth larger. If you're doing the riding style you say, I wouldn't think you'd need the shorter gearing you now have. That might be fine for drag racing but for open terrain or trails you'd want taller gearing...possibly even two teeth larger on the c/s, which is what I run on my Warrior.Changing the rear sprocket to a smaller one would accomplish the same thing but at much greater cost and work.
As to the condition of your sprockets (both), the indication of a worn one is to see hooking of the teeth, which as a concave effect between the tip of the tooth and the bottom of it. The two sprockets and the chain go hand in hand insofar as wear is concerned. If one is worn out it will soon ruin the other component as well.
To check condition of your chain, make certain it is adjusted to the correct tension first. Then, grasp a link at the center of the rear sprocket and attempt to pull it away from the sprocket towards the rear of the bike. If you can see 1/2 a tooth or more, the chain is shot. Using it on a new sprocket will ruin the sprocket quickly.
Hope this clears up some of your thoughts re your post.