Engine won't rev up past 5k rpm

[Mykl8]

I have a problem with my 1985 FL350R it starts and runs but won't rev up and only goes slow.

Things that have been done
Carb cleaned twice in an ultrasonic cleaner
New belt
New c90 primary clutch
Secondary moves with a pry bar
New reeds
New oil
New fuel pump/filter
Carb slide opens full with throttle
Swapped coil then cdi with no change
Tested all needle positions
Stock intake/exhaust
Jets are 45 pilot, 142 main
I am at sea level / 300'

I've contacted 3 dealer/service places and all of them don't want to work on it.

Edit: Forgot to add link to video
https://youtube.com/shorts/8tMxMf_7y5g?feature=share4

[LiveWire]

On the back of the gear box is a black rubber cap over a switch. That is the change switch. It detects if in neutral for starting and if not in reverse. When in reverse, one of the two switches is open enabling the rev limiter. You can replace the switch or ground the wire to the frame to disable. You can do a temp wire to test if that is the issue.

[Mykl8]

Awesome!

If that's all that's wrong with it it'll be an easy fix!

Now I just gotta wait two weeks until I'm home!