Sewing Machine Creating Thread Tangles (Thread Bunching on the Underside)

Thread tangles are almost always caused by incorrectly threading the upper thread or an improperly inserted bobbin. First, remove all threads and clean the hook and bobbin area with a soft brush to remove lint. Re-thread the upper thread carefully with the presser foot raised and the needle in the up position, following every thread guide. Insert the bobbin correctly — the thread should feel slightly resistant when pulled, but not tight. Hold both thread ends firmly toward the back when starting the first stitch. If this does not help, check that the needle size and thread weight are compatible.