Any idea what causes this machine to skip every 10 stitches or so? It sews just fine on single fabric, but when I try to sew two pieces together, it skips. I'll get 10 perfect stitches, then one long stitch, then maybe 10 more perfect stitches before it skips again. Someone suggested I change the thread spool and see if it might be the spool that's causing a snag.
I do know there was a problem with it not sewing right due to the tightness of the timing belt. Once I loosened it a bit, it started sewing again. Could it still need adjustment?