I am looking for a movie title. The film was made around late eighties/ early nineties and involves a character named Joe, I think. He is a futuristic style cowboy that drives a motorcycle. All I can remember is that he wears a stetson and long leather coat and carries a water purifying device. He also plays the harmonica. I do not know if the setting is a post nuclear war setting, but I am sure it is set in the future. Any ideas?