JUKI MF-7700D Series Engineer's Manual page 11

Adjustment Procedure
1. When motion of thread is very rough, and stable seams can not be
obtained, there are cases where the condition can be improved by
the following threading.
(1) Wind thread around 1st thread guide
(2) Wind thread around the thread tension thread guide
2. When using more stretchable thread (wooly thread or the like), the
threading as given below does not make thread stretch and neat
seams can be obtained.
(1) Do not pass thread through spreader auxiliary thread tension
.
Do not pass thread.
(2) Do not pass thread through the looper thread tension disk.
Refer to section
(Caution) Even when using wooly thread or the like, seams are
more stabilized by passing thread through looper thread
auxiliary thread tension
Engraved marker line
.
.
E
.
Results of Improper Adjustment
o When threading is not properly
.
– 7 –
performed, not only sewing
trouble occurs, but also needle
breakage is caused. So, be
careful.