I had an ´02 LC4 which was a very good bike, but it did vibrate. There was some discussion on the various KTM forums about it, but despite a number of different potential solutions, it still vibrated. I´d say it´s kinda the nature of that big torquey motor. I´ve ordered a new (2005) 640 LC4 Adventure and fully expect it to vibrate too, but I´ve decided to just let that go and enjoy the bike as it has soooo many great features.