Joe, the 500 does not run slower when adjusted properly. In fact, you gave me the information on how to make the adjustment. It's in those screws which I think are under and to the front of the feed dogs. (I'm not at the machine right now.) You gave me the gaps to set, and when I did, it ran perfectly, and fast. Do you remember that? Do you need them again?
I agree about the oil in the bobbin case and also a drop in the ring around the bobbin case, plus everywhere else the machine needs oil. I frequently use my Singer 500, which I got running again with help from folks here.
Now Miriam. Ahem About you. What do you mean, you're just a woman, so how would you know? Ahem, ahem. You are one of the most knowledgeable women regarding sewing machines I've ever known. If I knew more about you than that, I would probably think the same thing in any area of expertise you have. Plus that, please don't put down women (or was it a joke?). We are a capable bunch. I am a woman too, and (retired) engineer, with the final authority for all aerospace programs assigned to me and many millions of dollars of the company's profits. It doesn't fly until I say it flies. I am a woman, and I made it a point to know what I was doing, and then to double check it, because lives depended on me. I am a woman, the only woman there, and I stood up to any man who wanted to do things the fast and dirty way because, again, lives depended on it. I did my homework and could prove what I said. I got a lot of respect for it, too. If you have flown anywhere in the past decade or two, it may just be that a woman owns a big part of the fact that you got there safely. You are a woman, a capable and worthwhile human being. I'm glad you are on this board. Lecture over.