Gammill Encoder O-Ring (set of two)
Many times the cause of skipped stitches can be traced back to encoder o-rings that are old. They will last up to 5 years but in a high-sunlight environment I have seen them disintegrate in just 10 months. If the machine only skips on “regulate” but the manual speed mode the stitching looks fine, it could be the encoder o-rings. We always put on a new pair during each tune-up.