Maybe this is too obvious, but I'll go out on a limb...check to make sure the tank is venting properly. Duct tape the fuel cap so it won't close all the way ( but won't dump ALL the gas if you tip the bike over). If that helps, take the cap apart and clean the vent.
I have a love hate relationship with added fuel filters and have a box of used ones that I've taken off. Finally decided to trust the screen on the petcock tubes and replace the fuel line every year so it doesn't shed rubber. Replacing the petcock with a manual non-vacuum (no diaphragm) one eliminates one additional source of particles
UncleWray's Motorcycle Painting & Upholstery
Our Motto: "If it looks real bad from a mile away, you know you came to UncleWray"
Our Guar-ron-tee: "If it doesn't look bad from a mile away, we'll drive you closer till it does!"