15
990D
Correct Setting:
Both right and left needles should have an equal clearance between the front edge of the needle
holes on the needle plate. The standard clearance between the left and right needle and the lower
looper is 0 mm to 0.05 mm. The standard clearance between the needle and the rear needle guard
is 0 mm to 0.2 mm.
The above standard clearance allows the needle to slightly touch the front needle guard.
To adjust:
1. Remove the face plate unit, presser foot, needle plate and needle.
2. Before loosening setscrew C, attach the needle gauge #787-G02 to prevent change of needle
bar height during the adjustment.
Attach two #11 needles on the needle clamp. Loosen the setscrew C.
Adjust the clearance between the needles and the front edge of the needle holes on the needle
plate by turning the needle bar in the D or E direction while pushing up the needle bar to
prevent change of the needle bar height.
Retighten the setscrew C and remove the needle gauge.
3. Remove the left needle only.
4. Turn the handwheel toward you to bring the tip of the lower looper from the left hand to the rear
side of the right needle.
5. Loosen the hexagonal socket screws A on the front needle guard and open a space between
the front needle guard and the needle.
6. Next, loosen the hexagonal bolt B, and slide the lower looper unit to the front or to the back to
adjust the clearance between the right needle and the lower looper.
The clearance should be 0 to 0.05 mm. Retighten the hexagonal bolt B.
7. Change the right needle from #11 to #14.
8. Push the right needle by the front needle guard to adjust the clearance between the needle and
the lower looper. The clearance should be 0 mm to 0.05 mm.
9. Attach #14 needle on the left needle position and turn the handwheel toward you to check the
clearance between the left needle and looper.
Make sure the front needle guard is touching the needle slightly and rear needle guard is not
touching the needle.
10. Check the timing between the needle and the lower looper.
11. Recheck the needle bar height and the clearance between the needle and the lower looper.
TO ADJUST THE CLEARANCE BETWEEN THE NEEDLES AND THE LOWER
LOOPER/NEEDLE GUARDS
Note:
The needle is set at right needle position on this model. Also, the needle setting position can be
changed from right to left for the wide stitch sewing so that the following adjustment is required.
