Problem
Cause
Correction
Upper thread breaks
1.The machine is not threaded correctly
1.Rethread the machine
2.The thread tension is too tight
2.Reduce the thread tension (lower number)
3.The thread is too thick for the needle
3.Select a larger needle
4.The needle is not inserted correctly
4.Remove and reinsert the needle (flat side towards the back)
5.The thread is round wound the spool holder pin
5.Remove the reel and wind thread onto reel
6.The needle is damaged
6.Replace the needle
Lower thread breaks
1.The bobbin case is not inserted correctly
1.Remove and reinsert the bobbin case and pull on the thread. The thread
2.The bobbin case is threaded wrongly
should pull easily
3.The lower thread tension is too tight
2.Check both bobbin and bobbin case
3.Loosen lower thread tension as described
Skipped stitches
1.The needle is not inserted correctly
1.Remove and reinsert needle(flat side towards the back)
2.The needle is damaged
2.Insert a new needle
3.The wrong size needle has been used
3.Choose a needle to suit the thread and fabric
4.The foot is not attached correctly
4.Check and attach correctly
Needle breaks
1.The needle is damaged
1.Insert a new needle
2.The needle is not correctly inserted
2.Insert the needle correctly (flat side towards the back)
3.Wrong needle size for the fabric
3.Choose a needle to suit the thread and fabric
4.The wrong foot is attached
4.Select the correct foot
Loose stitches
1.The machine is not correctly threaded
1.Check the threading
2.The bobbin case is not correctly threaded
2.Thread the bobbin case as illustrated
3.Needle/fabric/thread combination is wrong
3.The needle size must suit the fabric and thread
4.Thread tension wrong
4.Correct the thread tension
Seams gather or pucker
1.The needle is too thick for the fabric
1.Select a finer needle
2.The stitch length is wrongly adjusted
2.Readjust the stitch length
3.The thread tension is too tight
3.Loosen the thread tension
Uneven stitches, uneven feed
1.Poor quality thread
1.Select a better quality thread
2.The bobbin case is wrongly threaded
2.Remove bobbin case and retread and insert correctly
3.Fabric has been pulled
3.Do not pull on the fabric while sewing, let it be taken up by the machine
The machine is noisy
1.The machine must be lubricated
1.Lubricate as described
2.Fluff or oil have collected on the hook or needle bar
2.Clean th e hook and feed dog as described
3.Poor quality oil has been used
3.Only use good quality sewing machine oil
4.The needle is damaged
4.Replace the needle
The machine jams
1.Thread is caught in the hook
1.Remove the upper thread and bobbin case, turn the handwheel
backwards and forwards by hand and remove the thread remands.
Lubricate as described
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