Brushes are inexpensive and easy to change. And to check on to see if they are good. I just took a featherweight service class and she said if you check the one easy to get to and it is good, the other one is too because they wear at the same rate.

Did you check the foot pedal? It may need readjusting. I bought a featherweight on ebay and it refused to sew but after opening and adjusting the foot pedal it sews great.

just think'n

Mine did the same thing recently and it was because of a little piece of thread stuck behind the bobbin casing. There is a great video of how to fix it on line on the Singer Featherweight 221 & 222 Sewing Machines group. I always learn so much from this site.

It could be the foot pedal that is worn and is not making the proper connection.

My FW sews great, but I have a Singer 99K that does not run. I'm going to take it in to my sewing machine shop and if the motor is no good, I will convert the machine to a hand-crank model.