Need to clean the carb again, the float needle is still sticking open. The only other thing that could cause gas to leak out the carb bowl overflow hose is if the carb bowl drain screw was linking, but I doubt it. Sounds like the float needle is sticking open to me.
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.