I'm trying to quilt a lap size quilt on a Singer sewing machine with a walking foot. When I put on the walkiing foot, and sew a straight line I am able to pull on the top thread and remove it like I had done a gathering stitch. I have set the tension as low as 0 and high as 9. At 9 I'm not able to pull on it as easy, but it will try to gather. Should the tension be that high?