Singer 354B bobbin question
Hello everyone,
Yesterday I popped in the local sewing shop to buy some thread and they had vintage serviced SM for sale... Long story short I came home with a thread pool and a Singer 354B Starlet (aka Genie in the US)
(photo from the internet as I have battery problems on my phone and cannot take pictures at the moment)
[ATTACH=CONFIG]609899[/ATTACH]
The machine had one plastic bobbin inside (already full of thread) so the lady at the sewing shop sold me some "no brand" plastic class 66 bobbins.
Here is my problem:
When I sew with the bobbin that came with the machine everything's fine but when I use some of the bobbins I bought the top seam is all loopy (so I guess a problem with the bobbin thread...)
So, was I sold the wrong type of bobbin (they look similar to the naked eye)? Do I need "Apollo-style" bobbins?
Or are my no-brand bobbins just rubbish?
I found a user manual online mentioning #172336 bobbins but Singer seems to have changed the reference numbers (or discontinued that reference number...)
In a nutshell, I'm lost! Can anybody help?