fig. 14-1
fig. 14-2
a
b
0-0.5 mm
fig. 15
a
fig. 16
a
- 13 -
14. BACKLASH OF HOOK GEAR
If there is too much play on the hook gear on the turning
direction, it may be the cause for machine not to sew
properly and/or making excessive sewing noise.
1. Remove the needle plate and bobbin holder.
2. Tilt the machine backward and remove the bed lid by
removing the screw and sliding it to the left. (fig. 3-2)
3. Loosen the 3 screws (a) and move hook base (b) up or
down. (fig. 14-1)
4. Re-tighten the screws (a) tentatively and check follows.
• Free play at the tip of hook may be 0-0.5 mm. (fig. 14-
2)
• Attach the needle plate and check that the feed dog
does not touch the needle plate.
If touching, rotate the base (b) slightly.
5. Tighten the screws (a) securely.
When you have adjusted the backlash of hook gear,
check the timing of the hook again. (sec. 3)
15. UPPER THREAD TENSION
UNIT
The upper thread tension regulator unit has been
adjusted to the best sewing conditions at the position “4”.
However, if you wish to change this, do it as follows.
1. Remove the light cover.
2. Adjust the tension by turning the tension regulator
screw (a) that is located on the side of the machine
either to the left or right. (fig. 15)
For a stronger tension, turn screw towards the right
and for a weaker tension, turn screw to the left.
16. ADJUSTING THE LOWER
THREAD TENSION
The bobbin thread tension is correctly adjusted at the
factory and normally it would not be necessary for you to
make adjustments yourself. If adjustments are necessary,
to obtain a weaker bobbin thread tension, turn the screw
(a) which is located on the front part of bobbin case
counter clockwise, and for a stronger tension, turn screw
clockwise. (fig. 16)
