3800 Open Water Tank Question

[Hifirush]

I am tracking down an issue with my water system on my '03 3800 Open, and am trying to figure out how the heck to get the 90 degree threaded adaptor (according to the build sheet the boat came with in the binder) out. That thing is really, really in there and it looks like it should just screw out, but dang! Any hints or has anyone done this? I am hoping that the end of the pick up tube is clogged or the tube itself is has a crack and I clean and/or replace it. I am losing prime and the pumps run and water doesn't really come out of the faucets..... 

Thanks, Matt