Iím currently riding my 2017 F 800 GS on the TAT. In Salt Lake City for a few days. Came from sea level in NC. I have been running premium fuel, 91 octane out west and I am getting what sounds like low octane knocking when I first start out at low RPMs If I rev it high and ride the clutch out no knocking. Do I have a fuel issue or am I looking at valve adjustment? Currently only 8800 miles on my bike started doing it 2500 miles ago as I got up in elevation. I know higher octane isnít necessary at higher elevation? Any suggestions?