Just bought a 2003 100th anniversary Sportster 1200. I'm having a problem with an oil leak. It doesn't seem to be major...yet. Everything is fine if I'm just riding around the neighborhood. No problems at all. But when I ride a little bit longer (for about an 45 min - an hour) I find oil under the bike the next morning. Again this only happens if I ride for about 45min-1 hr. If I ride around the neighborhood (about 15-20 min) everything is fine. No leaks. Any answers or suggestions?