1.There may be bits of thread, lint, or dirt in shuttle (bobbin) area.

2. Poor grade or in- correct oil type may have been used or machine was oiled improperly.

1. Remove bobbin and/or case and clean area with brush, pointy object, straight pin or q-tip.

2. Oil machine only with non-acid, non-gumming oil such as 'sewing machine oil'.

3. Check all visible screws for tightness.

1. Inferior thread may have been used, or thread may be knotted somewhere. Needle may be too fine for thread or fabric.

2. Upper tension is too tight.

3. Needle is not in needle clamp properly, or may be bent or in backwards.Also, needle may be too sharp for type of fabric, or may be dull or blunt.

4. Feed dog does not move material freely.

5. Needle plate hole has sharp edges or shuttle has rough spot.

1. Change to a better quality thread. (Gutterman, Dual Duty, Coats, or Molyncke)Avoid 5/$1 specials! Change needle to correspond with weight of thread and fabric.

2. Adjust tension by loosening it. (looser= lower number on knob)

3. Replace needle

4. Clean lint or threads from feed dogs, adjust stitch length.

5. Smooth with fine emery cloth or file.

6. Check threading of machine. Place end of spool with the thread slot to the bottom.

1. Inferior thread or mis- matched thread.

2. Tension on bobbin case is too tight.

1. See # 1 above. Make sure thread on top and bottom is same quality and weight.

2. Adjust tension of bobbin case if applicable.

1. Needle is set incorrectly in needle clamp, bent or dull. Needle size may be wrong for the thread type. Inferior or wrong type needle is being used, or needle may be 'gummed-up' with something.

1.Check needle for correct positioning, correct type and size, and if gummed-up,use alcohol on cotton ball to clean it. If unable to clean it, discard and replace the needle. Replace bent or dull needles.

1.Needle is in needle clamp too low, or needle is in backwards.

2.Needle too fine for heavy fabric.

3. Top tension is too tight or thread is wrapped around something. Needle may be in loosely.

4. Operator pulls fabric ahead of the feed dogs and causes needle to hit the needle plate.

5. Fabric is too thick and too heavy for your machine.

1. Replace needle; make sure it is inserted properly.

2. Replace needle with heavier one suited to the fabric.

3. Loosen Upper tension, and/or check to see if thread is wrapped around something. See # 5 above. Check to see if needle is in correctly.

4. Allow feed dogs to move the fabric, keeping fabric taut, but not pulling it.

5. Try using a 'jean-a-ma-jig' or similar tool to raise the presser foot high enough for ease of sewing, 'walk' the machine through thick areas by hand-rolling wheel toward you.

1. Poor thread quality or knots in thread.

2. Thread is wrapped around spool spindle.

3. Tensions improperly set.

4. Dirt, lint, or thread in bobbin case.

5. Blunt or bent needles.

6. Needle in backwards or not pushed up all the way into needle clamp.

7. Bent bobbin, overfilled or unevenly filled bobbin.

1. Check thread placement, replace poor thread.

2. Adjust tensions.

3. Remove bobbin and/or case and clean.

4. Replace needle, insert properly.

5. Replace bent or damaged bobbin, re-thread unevenly threaded bobbins