sjdal,
Here is a site that explains how to clear thread jams from the FWs. Since the 301s use the same bobbin arrangement you can use those instructions. Cleaning out the bobbin assembly is a good idea. You never know what the previous user did to the machine.
{
http://thefeatherweight221factory.com/page10.php }
Look down at the bottom where is says machine or thread jams.
Joe