If your sewing machine runs heavily or is doing loose stitches, does not feed properly or breaks the needle thread, some simple but essential things can be done before calling the repairman. In fact, 75% of common sewing machine troubles can be fix by yourself at home, in front of your machine.
IMPORTANT! NEVER store your machine in a damp area or near a heating source.
WHEN THE SHUTTLE HOOK BECOMES JAMMED: Occasionally, the bobbin case shuttle accumulates loose pieces of thread which are slowing the shuttle movement up to a point the shuttle will jam completely. Remove the bobbin case and push the shuttle race cover buttons sideways. Remove the race cover and clean the inside for any dust and lint. Remove the shuttle hook and clean out all thread and lint. Clean the shuttle race and put a drop of sewing machine oil on the shuttle drive shaft. Replace the shuttle, shuttle race cover and push the buttons back to their original position. On the picture below, A is for the race cover, B for the 2 race buttons.
WHEN THE MACHINE RUNS HEAVILY: If your machine work slugishly after standing idle for sometime, apply a drop of oil to each part movement on top and bottom, as illustrated below:
Then run the machine rapidly for a minute or so. The oil will irrigate in all the oil wells and it should run again smoothly.
WHEN THE MACHINE RUNS HEAVY BY OTHER REASONS: (1) The motor belt is too tight, or has jumped off from the pulley or hand wheel. Damaged belt with rubber residue at a specific place. Loosen belt by adjusting motor bracket or replace belt with a new one. (2)The bobbin winder is not released causing excessive friction. Release the bobbin winder and check for worn rubber tire. (3)Machine is lubricated with unsuitable gummy oil. In the worst case (when the hand wheel is hard to turn by hand), apply one drop of kerosene on top of machine first and try the hand wheel. If it is still hard to turn, do the same thing to the bottom of machine. Apply fresh sewing oil immediately after.
MAKING LOOSE STITCHES OR LOOPS ON UNDERSIDE OF MATERIAL: Upper threading is not correct, the presser foot is not completely down, the thread is not passed between the tension discs. Refer to your manual to thread properly the upper thread. Always thread the upper thread with the presser foot up. After passing the thread between the tension discs, make a simple test by lowering the presser foot and pull the thread: you should feel a tension in it. Be sure the tension dial is not under number 4. If no tension is present, the tension system is clogged by a piece of thread or lint. Check the bobbin case and the bobbin for dents or out of shape. Dropping metal bobbins on the floor often deform them. You should feel a small tension when pulling the thread out of the bobbin case. Be sure to pass the thread through the opening in the bobbin case. The thread gets a tension by passing under the leaf spring which can be adjusted with the small screw. Poor stitches and bas seams may happen for the following reasons: The bobbin is wound unevenly. Upper thread tension is too loose or too tight. Bobbin thread is too coarse for material. The needle is not suited for material. The needle is damaged. Uneven thread tension caused by thread of poor quality.
IF THE MATERIAL WRINKLES: The needle thread tension is too tight. Sewing with the stitch lenght dial at zero. The presser foot pressure regulator is too tight. Release some pressure on the presser foot.
IF THE MACHINE DOES NOT FEED PROPERLY: The stitch lenght regulator dial is set at zero. The feed dog is dropped. The presser foot pressure is insufficient. By removing the needle plate, remove any lint, dust between and under the feed dog. You may find some accumulated lint under the needle plate.
IF THE BOBBIN DOES NOT WIND PROPERLY: The bobbin winder tire needs replacement. The thread is not passed through the small bobbin winder tension cup. The bobbin is deformed.
IF THE NEEDLE THREAD BREAKS: The needle is inserted incorrectly, the flat side of needle is facing the wrong position.The needle is not inserted all way up in the needle clamp. There are knots in thread. The needle is too fine for the thread used. The needle is bent or its point is damaged. The stitch hole in the needle plate is rough or sharp. poor quality thread.
IF THE MACHINE STOPS WHILE SEWING: The needle is inserted incorrectly. The needle is bent or blunt. The needle is threaded improperly. Wrong size of thread used. Always use the same thread on top and bottom bobbin. Thread is too heavy for the needle.
IF THE NEEDLE BREAK: The needle is bent. The material is pulled from behind the needle. The needle size is too small for the material. Use a bigger needle especially when sewing elastic.
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