JUKI MOL-254 Engineer's Manual page 17

Adjustment Procedures
○ Adjust so that the slit plate passes almost the center of
the sensor and there is no interference, then tighten
setscrew .
1) Bring the needle bar to the lowest position of its stroke.
2) Loosen the idler pulley and loosen the timing belt.
3) Adjust the setscrews in connecting collar
position of the needle bar as shown in the figure on the
left.
4) Stretch the timing belt with the idler pulley and check the
position of the setscrews. (The position becomes as form
A.)
(Caution) The position of the screw may be shifted when
stretching the belt. Stretch the belt again since
the crest of the belt is shifted by one.
Results of Improper Adjustment
Timing with the hook on the rear
side is improper and stitch skipping
at the lowest
or defective thread pulling will result.
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