While you wait for answers, we may have found some information which could help you.
Click here for Bobbin Case Machine
thread OK on top but not at bottom?
How to unjam a stiff wheel on a Janome 6260?
Janome MC3000 noise?
how can i fix my memory craft 8000?
long arm quilting machine?
My new home memory craft 6000 will not draw the bobbin thread up?