Hi Barbara,
As you haven't used the machine for a while it would be a good idea to check the sponge bar on the 891. Over time the foam degrades and does not put enough pressure on the needles. This is not usually too much of a problem when using the main bed only but will cause problems when you try to use the ribber. To be most effective the foam needs to be about 1/4 inch above the metal of the bar.
Hope this helps,
Sue
November 2010