Your topic title and questions all confuse me. Have you swapped the OEM carburetor for another? If you have, I think it wouldn't've been easy to get an exact match.
Far as the tank is concerned, didn't you pretty well clean/purge this one out with all the fuel pump changes? I thought you'd said it was clean.
LONG time ago, but my recall is all the filtration ours had was the sock in the tank and an inlet filter in the carb. I added a plastic inline filter in the line at a joint along the frame rail near the driver seat.
