Idles great, won't rev

It has been a few years since I have been on the forum. I am back, looking for advice.

My bike has been running great for years, but sat over the past winter. I actually ran it around the yard a few times, and had stabilizer in the fuel. I started it a few weeks ago, and it started right up and idled fine, but it won't rev up. As soon as I give it any gas, it just sputters and spits and will not run much at all over idle.

I assumed I had a clogged main jet, so I pulled the carbs and the jets appeared to be clean. I went ahead and gave the carbs a thorough cleaning anyway, stuck them back on and it still does the same thing. Number 1 exhaust is just warm. Swapped the plugs and wire with number 4, but didn't change a thing. Any Ideas?

 

Blocked inline fuel filter?

 

I wish. I have swapped to an auxiliary tank now without a filter.

I don't have a tach, but I would guess it literally won't run over 2000 rpm. It goes from running good to crap when I hit the gas.