The lever is dicsussed on page 15 of the manual which is page 9 on that PDF.
You will love this White 77. They are great machines. The most common problem with the Whites are flat spots on the rubber motor pulley. Repair shops should have replacements. To prevent those flat spots place some kind of spacer between the motor and machine when you won't be using the machine for a few weeks or longer. I use a 4" piece of an old yard stick, which is long enough to stick up and be seen so I won't start sewing with the motor disingaged.
Originally Posted by
kpelletier83
Thank you Mizkaki for helping me find the correct Manual. It is funny though.....there is no mention in the manual of that lever. I will just put it on S and leave it there. No attachments and no plans to do anything fancy with it anyway.