My buzz is around the same RPM range, likely due to increased engine vibration at that RPM. If you can still hear your buzz at 6k RPM in 6th gear, it must be a loud buzz lol. I cant hear much more than wind at that speed. If I'm riding at 6k rpm or above, it's because I'm hauling @$$ and having fun, and I definitley don't notice the buzz at that point. I've had all the fairings off, had the tank off, and put it all back together...buzz is still there. Like I said before, I know everything that matters is secure, so I'm not going to drive myself crazy trying to find the buzz. If your dealership is willing to take a shot at it, that's cool. Can't hurt to try. If your bike comes back with the same buzz, I wouldn't worry about it.