Ok, so yesterday looked at the Corsa junction in more detail. It turns out that the brown I was seeing is some type of grease. I looked at the other 3 similar junctions and they had the same stuff. I can't imagine this was something the first owner did in the first 90 hours of owning the boat. I'm going to call Formula and see if they can explain it. Rip, do you have Corsa on your boat?

Probably to slide the rubber over the connection. Rip has mufflers like mine, no Corsa.

I'd inspect the rubber or replace as necessary. Tighten it up and see if that's the fix first.

Dave