Although I detest the four-strokes for their noise as much as anyone, I guess I should say the loudest bike I've ever heard was a mid-70s KX250. The other bikes were loud, but when one of those went by it was like Eddie Van Halen doing Eruption with his 6,000-mile-tall amp cranked to 12. That said, when one of them wasn't right next to you, you didn't really notice anything being loud. But when some guy decided to bring out his old Yamaha four-stroke and mix it up with the new-fangled two-strokes, it not only rivaled the KX250 in-close, but it shook the ground almost as much even when it was on the other side of the track. Ridiculous. Fortunately, the Woodland track is a long way away from any significant development.