Things You'll Need
Kenmore sewing machine
One major factor in achieving the perfect sewing stitch for your project is having your tension adjusted perfectly. Without perfect tension, you will notice your stitches are either too loose on one side or both sides of the fabric or your stitches are so tight they are causing pinching and puckering on one or both sides of your fabric. However, these issues are not always a sign of poorly adjusted tension. They could be indicators of other issues with your thread, your fabric selection or your machine.
Load your Kenmore sewing machine with the right thread and bobbin thread for your project. If you use the wrong weight thread for your fabric or severely uneven weights of thread, this can cause the appearance of a tension problem when it is, in fact, a thread weight problem or a problem with your sewing speed. If you go too fast, you will break the thread. If you go too slow, you can cause loops. Uneven pressure can cause stitches to vary greatly.
Test your Kenmore sewing machine's tension by sewing on a piece of scrap fabric. If your tension is way off, then test on some basic cotton or a firm blend simply to get your tension right. Do not try to start adjusting your tension on silk or leather. Get a base adjustment on a more standard fabric first.
Look at the top threads and bottoms threads. If the tension is off on one side, it will usually affect the other side slightly. So select the side that looks more maladjusted to start adjusting the tension.
If the top thread is too loose or too tight, you will need to adjust the tension dial. This dial is usually located a few inches above the needle on the Kenmore machine body. Usually, your machine will have markings to indicate which direction tightens the tension. If these have worn off over the years, watch the dial as you turn it. If it appears to move toward the machine body, then it is tightening.
If the bottom thread is too loose or too tight, then you will need to open the door to the bobbin case. On some Kenmore models, there is a little screw near the bobbin case that can be adjusted slightly to adjust the tension. On other Kenmore models, there is a screw on the bobbin case itself--not on the bobbin, but on the bobbin's casing. This will also adjust the bottom thread tension. Adjust the bobbin thread tension to make slight changes.
If the thread is looping severely on one side, the thread weights might be off. For instance, look to see if you have a lightweight thread on the bobbin and a heavyweight one on the top. If the thread keeps breaking, the top tension or bottom tension could be too tight or the thread is too lightweight for the material you have selected. Check your combination of threads and material. Also make sure you are using the right weight needle and the right foot for the sewing step or project you are working on.
If your Kenmore sewing machine's tension is off severely or if you have not used your Kenmore in a long time, then you might need to take your machine in to be serviced. Sometimes, the inner parts need to be oiled or the entire machine might need to be cleaned and calibrated by a professional. If you sew a great deal or if your machine sits idle a lot, both situations will usually require some servicing to keep your Kenmore sewing machine and its tension in perfect working condition.
Always consult your owner's manual. If you have lost or misplaced your Kenmore sewing machine's owner manual--or never had one--then find a replacement online (see link in References).
Do not get so frustrated with the tension that you overturn the adjustment knob and break it. If your tension is off severely, then drop your machine off for a quick servicing. A service call is usually less expensive and more cost effective than a repair call after you have broken a part.