I hope you are not trying to start it on old gas. It might start but it is liable to gum up your valve stems and bend some push rods. Use fresh gas.
Make sure the positive battery cable is a 6V cable. It should be bigger than a 12V cable. Since you say it is red, I suspect someone has put a 12V cable on it. You may have to go to a tractor store to get a 6V cable. Most chain auto parts won't have it.
