My quad is an 2000 Rancher ES 2x4

First question, when I first start up my quad, and press the gas (even slightly) it "coughs" and shuts off. Is this normal until it gets a little warm? Second, once I can push the throttle and the quad stays on, if I push in the throttle quickly, it takes a second for it to response and the engine rev. This is my first ATV, so I don't know if this activity is normal. Any comments would be appreciated.

Crooked, Mine does the same thing its normal. The engine is a little cold blooded you should find after you ride it for a few minutes it won't do that.

I usually let my quads idle about 5 minutes before I ride. That should fix them. Aslo take out any slack in your throttle cable and this should help.

Thanks for such fast responses!