Check all the tension units are clean and clear of lint
Ensure sharp new needle/s,
Make sure that when you thread the machine the presser foot is up so
the thread goes between the discs and not to one side, and that you have threaded through all the guides.
It may be there is lint trapped between the discs,
this will keep them slightly apart and reduce the actual tension,
sometimes dramatically.
If tensions appear correct, and the
thread is definitely in the channel between the discs, but still too
loose and looping, try raising presser foot and remove your thread.
Now,
with a 2" (50mm) wide strip piece of fabric 8 - 10" (20 - 25cm)
moistened with methylated or denatured spirit, gently insert the fabric
strip and clean between the discs with a see saw / to and fro action.
Now set up machine with 4 different colours, so you can easily see any changes you make.
Factory setting for all 4 tensions = 3.........try this setting first before altering anything.
Sew a test sample about 75mm (3") and look at the result, front and rear.
You will see anything tight or loose, so just adjust a little at a time with test samples each time.
If the actual knobs read anything other than the 3-3-3-3, after you have made your adjustments and are happy with the balance of tensions, it is quite simple to remove the knob....very gently pull it off towards you (without altering the new found correct tension !!) and pop it back on to read 3.
Hope this is all easy to follow, If you want any more help with this, just post back here, or, drop a line through the "Contact Us" page at
www.bargainbox.com.au