Welcome to the forums. Honda offered an optional speedometer kit for those, but don't know if they would still be available or not. Trail Tech sells aftermarket speedometers for sport ATVs, but I don't know if they offer anything for the utility ATVs. You could look on their website to see.
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.