Is there garbage in the tank ?
Almost reads like garbage in tank floating towards fuel valve and then causing a restriction.
Bike stops for a while or you get a fill-up and garbage floats away from fuel valve until gravity and suction make it float towards fuel valve again.

 

May very well be. I have half a mind to pull the fuel line and drain it into a bucket just to be sure. Something I thought about. I typically fill it up full before leaving the country to avoid rust or corrosion in the tank. Could have picked up trash along the way.

 

trash might be stuck on inside of tank.
The screen will not let it pass and it floats away.

 

The petcock screen is the fuel filter, the tank should be drained and the petcock removed and cleaned every so often as maintenance,
This is also a good time to replace the fuel hose, especially if it's old, the ethanol will eat up the inside of the hose and put rubber flakes in the carb, and could be the cause of your problem.
Might want to replace the crossover hose also.

I use the Gates Barricade injection hose, resistant to ethanol, and doesn't kink as easy as the regular Barricade fuel hose
https://www.gates.com/us/en/fluid-po...-000000-000007

 

Pulled petcock. Reset carburetor, gave it a topical cleaning, and retuned. Checked fuel that came out of tank. All looks good. Took it out and it runs like a million bucks again. Must have been the faintest of debris or just out of adjustment. I didn't spend much time tuning it after swapping the exhaust this last winter.

 

Sounds to me you forgot to mention this in your first post..... Of coarse a different set of pipes is going to change the way a motor will perform...

 

Yeah I did forget to mention. Although I did ride it this winter and all seemed fine. Could have been the temperature difference?

 

So what pipes did you take off and what did you put on? Looking at your sig it looks like an RB 2-1...

 

Took off freedom performance 2-2 and went with the RB 2-1.

 

I though it was a pro stock.... They breath very well mid to upper range... Not the greatest down low... over 3k , is ok...

So what have you done to the motor to have the need for that pipe?