Pro Boss GT-40 Surging at cruising speed

[The Hamster]

Its in the brass fitting. Its small, and similar to a screen you would find in a standard household faucet.

[ELECTROMAN]

I was able to remove the anti siphon valve and fuel pick up from the tank. The screen on the fuel pick up was clean. Then i removed the anti siphon valve from the 90 degree fitting, and learned there was another screen in there. This was one had gunk caked all over the screen. Sort of hard to believe it wouldnt impeed fuel flow. I feel fairly confident this was my problem. Im going to lake test tomorrow and i will update.

My fuel pick up tube won't come out all the way. The end seems to be bigger than the opening. Does the large outside nut have to be removed? I'm a little afraid to mess with that since I don't know how everything is held together.

Also, I don't have any screens on the anti siphon valve, or on the right angle fitting.