XJ900 squeal

Hi all,
I bought a 1983 XJ900 last summer. Had 39,000 miles. Needed some work. Had fork seals replaced. Brakes front and back serviced, including now rear rotor. New rubber connecting carbs to airbox and cylinders. Carbs synced. New rear shocks. Changed the oil (today). Supposedly the carbs had been rebuilt right before I bought it. It was running pretty good, except for intake leak, and the boxes and extra pieces for the carb kits were in the box of parts, etc that came with it. So I tend to believe carbs had been done. Anyway, it's running good now, except there is a low-pitched squeal at around 4,000 or 5,000 RPM. It tapers off as it goes to idle, seems to go away at higher RPMs.

Any ideas?
Any help is much appreciated.

 

Appears to be a speedometer and/or cable issue.

 

There is a thread on here about that. Lubricant the cable first. I will try and find the thread.

 

This might help.

https://www.xjbikes.com/forums/threads/speedo-and-tach-dissection-with-pics.15303/

 

Thanks, I'm hoping a new cable fixes it

but good info!