Being made in America adds value and individualism to the motorcycle. It sets it apart from the rest. Manufacturing Harley-Davidson motorcycles overseas could have some potential advantages. Customers might not have to wait as long for delivery of the bike. Another possible advantage is that Harley-Davidson could use an overseas plant to build models that are only available in say Europe much like Ford does with some of its automobiles.
Manufacturing abroad can also have potential problems as well.
As mentioned above, the American rebel image is a large part of the Harley-Davidson enigma. Customers may be reluctant to purchase a German or Japanese Harley-Davidson. Quality control might present a problem overseas as well. The pride and craftsmanship built into a Harley might prove to hard to instill with a foreign workforce. Being made in America ensures management can keep a close eye on production and quality control methods.