Beisler 739-23-1 Service Manual - Manual (Page 13)

2.9 Needle thread tensioner
Caution! Risk of injury!
Switch off main switch !
Adjust needle thread tensioner only when the sewing machine is
switched off.
Instruction and inspection
Press axis 1 of the needle thread tension to open it
by approx. 1 mm.
Adjustment
–
Loosen screw 3.
– Move cylinder 2.
If the needle thread tensioner is fully closed and without thread
between the tension discs, axis 1 should have a play of 0.3 mm.
– Tighten screw 3.
3-13
3 2 1