Operation Manual

18.
Trouble
Shooting
Machine
Skips
Stitches
Cause
Remedy
Wrong
needle
system.
For
correct
needle
system
see
Chapter
6.
Needle
bent.
Insert
new
needle
as
instructed
in
Chapter
7.
Needle
inserted
incorrectly.
Orient
needle
so
that
its
short
groove
faces
toward
the
sewing
hook.
Incorrect
threading.
Thread
needle
as
instructed
in
Chapters
5
and
8.
Thread
Breaks
Cause
Remedy
For
any
of
the
reasons
indicated
above.
See
remedies
listed
above.
Tread
tensions
too
tight.
Regulate
tensions
as
instructed
in
Chapter
10.
Knotty
thread.
Use
high-quality
thread
only.
Needle
point
blunt
or
damaged.
Replace
needle.
Thread
snarled
up.
Check
upper
threading
from
spool
of
thread
to
needle.
Faulty
Stitch
Formation
Cause
Remedy
Improper
tension.
Regulate
tensions
as
instructed
in
Chapter
10.
Wrong
needle
size
and/or
thread
used,
Correlate
needle,
thread
and
fabric
as
shown
in
table
in
Chapter
6.
Pieces
of
thread
between
tension
discs
Remove
thread
and
re-adjust
tension
as
or
under
bobbin
case
tension
spring,
instructed
in
Chapter
10.
Needle
Breaks
Cause
Remedy
Wrong
needle
system.
Insert
needle
of
correct
system
as
instructed
in
Chapter
6.
Needle
bent.
Insert
new
needle.
Needle
too
thin.
Insert thicker
needle.
Machine
Works
Heavily
Cause
Remedy
Lack of
oil.
Oil
machine
as
instructed
in
Chapter
3.
Wrong
lubricant.
Use
only
non-resinous
and
acid-free
sewing
machine
oil.
Hook
race
obstructed
by
pieces
of
Try
to
free
the
jammed
thread
as
you
rock
thread.
the
balance
wheel
back and
forth.
If
this
action
should
fail,
dismantle
the
sewing
hook
as
instructed
in
Chapter
13.
15