remove bobbin with bobbin case and thread cotton like you would while bobbin is in machine,that means through tension spring on bobbin case. hold the cotton in hand while hanging bobbin case with bobbin towards floor,bobbin case should not go down only when pulled slightly with other hand.adjust screw on bobbin case until you get tension close to this setting.if by change the tension will not come right you will have to remove both screws on tension spring and check for dirt between spring and bobbin case. hook timing is close to correct if the needle eye meet the hook on the upward movement(approx 5mm upwards)shout if you struggle
johan
January 2012