I agree with Toyota and dirtguy. I would look into the back of the carb and make sure the throttle plate is closed. You will have to use your finger to raise the slide in order to be able to see the throttle plate. The throttle plate isn't supposed to be completely closed, but it should be real close. It should just be opened slightly, just enough to idle. If it's opened too far, turn your idle screw to try to close it some. If it won't close, something is holding it open, so check your cable.
Most 4-wheeler problems are caused by a loose nut connecting the handlebars and the seat!!
You only need two tools in life -- WD-40 and duct tape. If it doesn't move and should, use the WD-40. If it shouldn't move and does, use the duct tape.