Hi Boomer,
Folks round here can probably advise but would need a little more info to really help. What's the bike's millage and what do you know of it's history?
They are a little 'buzzy' in feel, and some do have a vibration around 6.5k RPM, so if that's all your feeling then not a massive worry.
On the other hand if it's beyond the normal buzziness and all the way through the revs then maybe something simple like the carbs needing balancing. How is the idle? Is it lumpy? I.E. Once warmed properly up is it wandering around the revs, and if so by how much?
Or maybe it's not running properly on all cylinders. You can check the spark on the plugs quite easily, or you can throw cold water on the down pipes and watch to see if it evaporates evenly across the cylinders. I find one cylinder can be cooler at idle so I tend to give it just a few revs when doing this test. Or a non-contact thermometer can be used.
Have you checked the front sprocket? Sometimes they fall off; there is a replacement OEM part to fix that.
As always if it's been stood then fresh fuel, air filter, oil change, all the basic service items are in order.
Andy
