Hello guys, I need some help with my Intruder 1400. The engine vibrates at around 3400-3700 rpm. This is a bit annoying and tiring on the highway because it translates into shaking at 115-125 kmph in fifth gear which is the highway speed limit in some European countries. Is the vibration in this range something normal for this model? Someone suggested that maybe my carbs need adjustment? Or maybe it has something to do with the replaced rear cylinder exhaust valve a few months ago. There is no vibration above 3400 rpm and above 3700 rpm.