First Serger

Just used my new (to me) serger for the first time. Viking 1000L. I'm surprised at how easy and smooth it sews. And getting it threaded was a lot easier than I was expecting.

The issue I'm having is, I think they call it baconing. Where the seem is a bit wavy. I feel like the presser foot is putting too much pressure down? But I'm guessing I'm doing something wrong as well.