you will have to remove bobbin case and do a little precision work that require patience and concentration.work on a piece of cloth so as not to loose screws.the small screw in middle adjust the tension,turn clocwise and observe if tension increase.if not you will have to remove the screws and remove spring tension plate.ensure you remember how you strip as to be sure to to put it back correctly.clean spring and area around and refitt all parts.to check tension pull cotton thru and their must be some resistance but not to much.the old hands know the tension feeling but your will be some trial and error to get it right. also check top tension.if pressure foot is lowered there should be some tension on cotton
johan, June 2012
