I did my own valve adjustments a few months ago. This noise seemed to be happening before then, and persisted after that adjustment. It has slowly been getting noisier (especially on really warm days). I am hoping that it is either a poor valve adjustment on my part anyway, or the rocker assembly. I was going to tackle the rockers myself, but I haven’t found anywhere online telling/showing exactly how to safely adjust it. Shifting the unit that holds the lower rocker arms in place holds both the intake and exhaust rockers… not sure how to close the gap on one without messing up the gap or, more importantly, the square alignment on the other.
Re push rods, I have heard about the issue of steel end tappets detaching from their aluminum shaft. I believe, since my clacking kicks in when engine warms up, the rods might not be the issue… just a bit of a hunch though.
I doubt the bike is going to explode on me, but i think i like a clean sounding engine… as clean as one can get an 1150 to sound anyway. 😉