The stitches aren't coming out right on my Janome 6600. They will be fine, then I'll get a long stitch (3-4x length of regular stitch), some more that are fine, then another long one, and so it goes. I have cleaned the bobbin, oiled it, changed the needle, switched bobbins and threads, rethreaded, turned it off for a day, played with the tension. I don't know what else to do. Any suggestions or does it need a trip to the repair shop? It is making a slight ticking sound when I sew too. And naturally I can't find my manual! :(