OK I have a White model 1740. Book says to lower the feed teeth, push the lever in and to the right. To return the feed teeth to the up position, push the lever to the front. I am still trying to figure out where this lever is, but maybe you already know. I'll keep studying the book and you can PM me if you want me to work with you. I haven't used this machine in about 6 months and I forget what it looks like. I do think that I covered them with a square plastic piece.