Jim Have you checked your bobbin tension and cleaned your bobbin case? I have been on numerous services calls lately,( both Amayas and EMTs) where I have found that the customer is cleaning the bobbin case as recommended but there is still a lot of lint and other garbage that remains under the tensioning spring,(especially if adhesive spray or backing is being used). So after they clean out the bobbin case they reset their bobbin tension and they have to tightened the screw more and more to achieve the correct tension. What is happening is that the residue from the oils,lints, and adhesives are forming a layer of gunk under the tension spring that can't always be completely removed with the usual method for cleaning the bobbin case. You may have already checked and verified this but I thought I'd bring this up. Hugo Torbidoni Melco Certified Technician/ EMC,EMT,AMAYA