What to do if the thread keeps breaking on my SunStar KM-757 Sewing Machine?
- TTony MillerAug 1, 2025
If the thread is breaking on your SunStar Sewing Machine, consider these potential causes. First, check the threading; incorrect threading (inserted from the wrong side) requires you to thread the needle correctly. A bent needle also leads to thread breakage, so replace it if necessary. Ensure the needle is inserted correctly and at the right height. Adjust thread tensions: reduce upper thread tension if it's too tight, and reduce lower thread tension if it's too loose. Also, adjust the stroke level if it's too large. Finally, check for scratches on the hook edge, feed dog needle hole, or needle plate and remove any scratches found.