Thanks everyone for chiming in!
I put 91 gas in it at a 40:1 ratio oil.
I updated from 54 to a 58 main jet.
drove it for about 5 minutes & it's still making that sound at that certain throttle position. I was thinking its pre-detonation because its a knock near the engine. Maybe it's the chain hitting the bike at that certain rpm or something?
Before this I had a phbg & a bigger pipe and it didn't make this noise. (I was even running 87 fuel). Now I switched to the stock carb (14/12 sha) & the pancake exhaust and this is when it started making the knocking noise.
If I can't figure it out I may end up having to replace the bearings and oil the flywheel stuff that was mentioned and go from there. I'm just confused because before it didn't make the noise and after the stock carb & exhaust now it makes it.