Singer 491D, Service Manual

Page: 6 / 44

58.73 mm − 491D200AA
66.01 mm − 491D300AA
- 2 -
TO SET NEEDLE BAR AT CORRECT HEIGHT
Fig. 2
THROAT PLATE
SEAT
TIMING
MARK
PREPARATION:
Remove face plate, slide
plate and throat plate. See
that needle is correctly set
in needle bar.
Lower end of bushing A,
Fig. 2 must be set as shown
in Fig. 2. To reset bushing,
loosen screw B.
CHECK:
When needle bar is at its
lowest point (during rotation
of machine pulley), UPPER
TIMING MARK on needle bar
should be level with lower end
of bushing.
Check timing of hook as
instructed on page 5.
SETTING:
Loosen clamping screw C, Fig. 2. Raise or lower needle bar so that UPPER
TIMING MARK is level with lower end of bushing. Then securely tighten screw C.
Replace throat plate and slide plate.
When replacing the face plate, make certain that the screw holes in the
face plate gasket are aligned with the respective screw holes in the face plate;
avoiding injury to the gasket and consequent oil leakage.
TO SET CHECK SPRING HEIGHT
PREPARATION:
Thread the machine and place a lightweight material under presser foot.
CHECK:
Turn machine pulley over toward operator slowly. When take-up lever
begins to rise, check spring D, Fig. 3 makes a slight dip and a return to its
higher position. Later, as take-up lever approaches top of stroke, check
spring D should be drawn all the way down; setting the stitch. As lever de-
scends, check spring D returns to rest.
C
B
A