It's my understanding that most new skimmers will take anywhere from 1-3 weeks break in...I know mine seemed to take forever, but was really about 2 weeks before I noticed that it was pulling skimmate. Since then, with adjustments and just knowing what to listen for, mine is constantly pulling skimmate. If yours is new, just give it time. During the break in, if you hear it making louder than usual noises or if it just doesn't sound right, adjust it. Before long, you'll get it to where you want it.
Lisa :happyfish