This is my first ever BMW (79 R100 RS) which I purchased 3 weeks ago. I really don't know much about how it should feel. With that said, I took my new ride out for a spin. I noticed that at stop lights the bike shakes side to side (as in pistons wanting to come through the cylinder head... like out of balance), and when the throttle is blipped it vibrates at low RPM's and rattles the fairing something bad, even though every fastener is tight. However, cruising anywhere past 4000 rpm it's all good. It almost feels like it's missing an engine mount. It's not BTW. Any ideas what this might be?