the cleaning is very important, and then you can pull the belt out all of the way and lubricate the bobbin for smooth operation
QUOTE(Garland @ Aug 29 2019, 03:45 PM)
And easy way to clean them up is in hot soapy water. Lower the whole mechanism into the bucket run it back-and-forth dry thoroughly. Trying to unwind the mechanism, and then reset it is troublesome.