Have you determined if it has spark at the sparkplug? If so, pull the sparkplug out and pour a small amount of gas into the sparkplug hole. Quickly, put the sparkplug back in before the gas evaporates. Make sure the kill switch is in the run position and try to start it. If it starts and runs for a second or two, the carb is stopped up.
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.