Here are photos of the process of getting to the race wick that helps oil the race. While cleaning the bobbin, case, and hook/race on the Singer 66-1, it is important to check the wick and replace it if necessary with a new felt one.
Remove bobbin plate, needle, foot, and feed dog cover plate.
Turn machine over to work on removal of the feed dog screw underneath the bobbin area of machine.
After removal of screw, pull out the feed dogs from top side of machine.
Now work from top side in bobbin area. Take note of red piece of material which is the oil wick inside the wick screw (located right side of ejector button). To get to this wick screw, numerous other items must be removed first.
Start by removing the pin that holds the ejector mechanism bar which is located right of wick screw on top of bar.
Grab hold of case and ejector bar; twist them to loosen from race, then pull them up and out of race.
Clean all items. I used rubbing alcohol.
Now it is time to remove wick screw from ejector bar. Using small long nose pliers to hold screw, gently turn screw counter clockwise to remove wick.
Removal of wick may take some time and require soaking in alcohol to loosen the red wick from the wire screw. Be patient, it will come out with time.
Now that all is clean up, it is time to cut new wick from thick red felt spool pin holder.
Leave some wick out long enough so that it will be able to touch the race (that is the purpose of the wick).
Insert back into hole that you removed it from by turning it in clockwise.
Now drop a little bit of oil in the case groove before putting case and ejector bar back in place.
This is how the wick should look resting against race.
Put feed dogs back along with all other cleaned up parts and screws that were removed.
Simple as that!! Have fun sewing!!!
P.S. There are some very old Singer 66-1 that do not have a race wick screw. One of my machines is this way. Here is a photo of that ejector bar without the wick screw.