Misty, you remove that 'carrier' by removing the needle plate (two screws on the top of the needleplate - not under the machine.) Take out the bobbin and bobbin case first, of course. Wipe it off with SM oil and look for any rough spots. When you put it back, be sure the 'finger' fits in the groove on the bottom of the needle plate before you tighten the screws. There is a page in the user's manual that shows this this. If you don't have one, you can download a free one from sew-classic. I think ISMACS has one, too.) One little ball of compressed lint can cause all kinds of problems. I'm using Connecting Threads thread right now and it's so linty my 301 told me she needed an extra cleaning. The bobbin just wasn't happy.