Kenmore Model 54, stitch length adjuster not working
 

The adjuster knob had been working. Until today. When I turned it to 5, there was the usual resistance, then a click and the knob kept turning. The stitches are now large, and turning the knob does not change the length. If I press and hold the Reverse button, and turn the knob 1/4 turn clockwise, the button remains in the pressed position. When I back the knob 1/4 turn counter-clockwise, the Reverse button releases. So I know these two functions are connected. But I cannot figure out how to re-engage the knob, or whatever it is that has to be done to make the knob make the stitches smaller.

Does anyone have any advice for me? Thank you.

Kenmore machines had some kind of oil that gums up. You'll need to oil with a good oil like Tri-Flo - I buy it from a bike store. I had a Kenmore on my bench this week and had to keep re-oiling daily. finally I flipped the machine on its sides - front to back side to side then upside down and ran the machine. Oil just needed time and a little effort to work into the right cracks.