Hello Deborah,
You won't get the teeth above the throat plate unless it is snapped on properly, make sure it fits flush flat down, make sure that if you have a drop feed mechanism that it is in the raised position.
If you type in www.kenmoresewingmachines and then scroll down to relics you should be able to get an instruction book.
Ken
drivewithken@blueyonder.co.uk, July 2007