Gurgle sound from bottem end

[Tenrilid]

Hello guys. I wanted to get a few ideas on what could be causing this sound. A little over a week ago I finally managed to get the bike running after 12 years of death and it ran quite well, with fresh oil btw. I have the feeling that since it was running the oil through the lines it started to break loose any crap/gunk that was sitting there for so many years. Last night when I started her up again, I hadn't messed with the bike since I started her up a little over a week ago, I heard a gurgling sound coming from the tranny area. My thought is that the built up crap that came out finally made it's way back to the oil pan and is causing a blockage in the oil strainer that's in the pan. Next weekend I will be draining the oil and removing the pan to check if I am right but I wanted to run this by you guys to see if I am right or if there could be any other issues.

Oh, and the oil pump seems to be operating correctly as it was still moving oil around.