This was the hard one for me when I was working on my featherweight. Once you take the throat plate off, you have to make sure that the "finger on the bobbin case" is positioned correctly between the bobbin case position springs under the bottom of the throat plate. The "finger" has to be at the top position otherwise it won't run with the throat plate on; but it will run without it. I, too, thought that I needed to adjust the position of the feed dogs, but all I really needed to do was to get that "finger" in the proper place. Hope this not only makes some sort of sense, but also that it helps.