I have touched a lot of Featherweights and in the process seen quite a few repairs that Singer had not thought of. Many times the driving force behind some variations of design is a belief that "the parts for a Featherweight are not available" which explains why I replaced my Featherweight's motor with a Hoover vacuum cleaner motor. In truth, very few parts for the Featherweight are truly difficult to find and the ones that are are not parts you would ever need, such as a lower main shaft. The really hard ones to find are those that are never needed so no one keeps them around, therefore they become "rare".
As many of you know Singer does not supply parts on machines that are more than ten years beyond a given machine's model change. Our Featherweights are only fifty years beyond that model change milestone so don't bother asking at the Singer Store for Featherweight parts or you will be told the truth; Singer does not make Featherweight parts any more, "but maybe you'd like to look at this new machine over here?"
Because of the popularity of the Featherweight machines there are quite a few companies that manufacture good Featherweight parts today. Using key words like "Featherweight 221" in a Google search will get you the names of people who can ship you good new and used parts. Spend a little time looking at various sites to learn the"going-price" of parts as there are some who just might try to gouge you a bit.
I am not going to endear myself to a few sellers but I would avoid "new" bobbin cases and hook assemblies. You are far better off with a good used bobbin case or hook assembly that works compared to nicely chromed parts that are problematic.
This aftermarket availability of replacement parts has its limits I fear. For a company to start manufacturing a replacement part there has to be a demand for them. Parts that are unique to the model 222 for instance are not manufactured anywhere and you will have to buy used parts. You can buy new motors for the black machine if you don't mind its not having the Singer name on it. You cannot buy a white motor for a white (I know, they are really green) Featherweight, you'll have to buy a used one or paint a new one white. Have fun matching the green color.
Don't disparage if you are told "these parts are not available any more" by the first person you talk to. These people would know there are parts available if they would just search around on the web a bit as I am asking you to do. Ebay is one souse of parts that works as long as you shop around and have an idea what something should cost before you remortgage to underwrite the first part you see. Those who sell on eBay are often fond of using the word "rare" but the only thing really rare is the seller who doesn't use the word rare.
Have fun Kids, these machines are going to be around long enough to be a problem for the great grand kids to have to figure out.
Source: Dave's Blog