Welcome to the forum!
Travis is absolutely correct about the manual. And as to your problem, it's possibly a sensor issue. Specifically, what would be a throttle position sensor. Although I have no idea what it's called on the mule. But it tells the throttle body how much gas, and air it needs.
I say possibly, because it could easily be a combination of problems causing the issue. Or a wiring problem. Since i'm assuming that it's likely CPU controlled, you'll need to find the trouble codes.