1) Replace Needle Loosen the nut two turns. Remove the old Needle and replace it with a new Needle. Set the new needle all the way back against the Stop Pin, and retighten the nut.
2) Check the Threading Refer to the Threading Diagram provided with the machine, and ensure that the threading is proper.
3) Check Cutter Sharpness Place a single strand of thread between the two blades. Turn the Handwheel by hand, and see if the thread is cut cleanly. If the thread is not cut cleanly, adjust sharpen, or replace the Cutter.
4) Check the Looper Settings Referring to the illustrations and descriptions provided help pin point the problem with the Looper Setting.