The 201's tension assembly is definitely awry. I know I am capable of fixing her but need a diagram which I saw once but don't know if I saved anywhere. Rosie lived with a smoker for a while - cleaned smoker residue off her. UGGHH!! No offense to smokers but it leaves behind a residue that is nasty to clean up. She does have 2 springs in the thread tension area but don't know how to assemble or even try to assemble correctly so it's off to search favorites and other places to see if I saved those diagrams. Please let me have saved them.
Update: Found manual on ISMACS site with good info. I am missing a piece of the tension assembly and not quite understanding how it goes together but will look for donor machine tomorrow for missing piece. FYI: Did save diagram for the 15-91 which was a big help but manual was more helpful.