No smell of anything burning. No backfire. Bike starts fine.
It does go away when the clutch is in.
Sometimes when shifting down it feels kind of like the engine wants to drop off the frame. I checked both bolts at the bottom of the frame and they're both there and on tight.
It's not noticeable in 1st to 3rd. 4th from 60-70 is tolerable. Fifth gear feels like a problem. Lots of vibrations and seems like it's straining rather than running smoothly. I'm afraid there might be something wrong with that gear. It is possible to blow just one gear? OR could it maybe be a bad spark plug?
That's the worst case. I did take a look at the tires, rims, and bearings but I'll check them again.
Going Strong, Since 12140 BP