think you will have to take it to technician or else you might ending up adjusting wrong setting bar inside machine.if you feel lucky remove top and find bar connected to needlebar and zigzag arm,loosen the small screw connecting lever and bar,make sure zig zag lever is on o and move needle bar to center.fasten screw and check operation of zig zag by turning handwheel and zig zag on max.repeat if needed. good luck!!
johan
February 2012