After I replaced bobbin tyre on my 201 I haven't managed to get it right again. It works fine, I just have to hold it down the last few rounds. I simple haven't bothered to sit down and fine tune the settings for it. There's one or two screws involved and a lot of test winding.
Does it click in place and disengage at all? Sometimes the mechanism needs oil, in the worst of case complete disassembly, cleaning and polish, but usually not. If it's very minimal, the stop and disengagement part might be manual.