Domestic machine problem.

[Grebo]

I have an old Reeds sewing machine. Metal body, nice & strong no fancy stitches just straight & zig zag, I use it for any thing that the industrials don't like, light work.  ::)
It has a bobbin case that fits vertically, all of a sudden the bobbin thread has started jumping out of the tension guide (on the bobbin case)  it all stays threaded up & sew's until I get an almighty jam up ?
I use decent quality thread & don't drive that fast  :-[

Any bright ideas ?  ???

[Darren Henry]

 :-\ A groove ( or other wear) on the inside of the tension spring ??  treat it like a carburetor ; gentle tighten it down counting the # of turns then pull it off and look

At the bottom of the "slash" there should be a wee hole where the thread doubles back over to the needle.  :-\ maybe some crud not letting the tread in?

[Grebo]

Cool, thanks I will give it a once over  ;D