Brother Industries MA4-B972C User manual

INSTRUCTION MANUAL
For
BROTHER MA4-B972C
High Speed Safety Stitch Overlook Machine
BROTHER INDUSTRIES, LTD.
NAGOYA JAPAN

CONTENTS
1. Specification 1
2.
Features 2
Operation 3
A) SewiiiK .Speed 3
H) Motor,
motor pulley and belt 3
C) .Settin^i up 3
D) Oiling, draining and maintenance 4
K) Needle
cooler device .5
F) Machine operating direction 6
(1) Installing needles 6
II) Threading 6
I ) Stitches 7
.1) Thread tension 7
1. Adjustment of thread take-up 7
2. Adjusting double chain stitch needle thread guide 7
3. Adjusting looper thread take-up and thread guide for overlock stitch 8
4. Adjusting looper thread take-up and thread guides for double chain stitch 8
5. Adjusting thread tension screws 8
K) Adjustment on pressure of presser foot; installing and removing feed dogs: and height of feed dogs 8
L) Adjusting stitch width 9
M)
Adjusting stitch length 10
N)
Adjusting differential feed 10
4. Adjustment H
A) Height of needles 11
F)) Relation between needle and under looper 11
C) Installing needle guard 11
I))
Matching needle guard and needle 11
F) Relation of needle with under looper and over looper 12
F) Relation between needle and double chain stitch looper 12
(1) Installing double chain stitch needle guard 13
II) Installing and
maintenance of knives 13
5. Trouble shooting 14
A) Thread breaks 14
H) Skip stitching 14
C) Needle
breaks 14
D)
Imperfect chaining-off 15
10 Improper thread tension 15
F) Foor trimming performance 15
(i)
Irregular stitches 15
II) Kxcessive wrinkles
along stitches 10
I ) Needles produce too large holes 16

1. Specifications
Name
Dimensions
Stitch form
Sewing speed
Stitch length
Stitch width
Height of presser foot
Lubrication
High speed safety stitch overlock sewing machine
355mm X 240mm X 270mm
Dust-proof, oil-proof, totally enclosed type
E13 & D12, K13A & D12, E12A & D12 simultaneous sewing
Overeclging and blind-hemming of garments, knitwears; Joint seaming on sleeves and
other types of sewing in general
6.000 stitches per minute
1.7mm-3,6mm (7-15 stitches per inch)
Needle g.aige; 2, 3. 5mm
Overedge; 3-5mm in- changing the needle plate
5mm
Automatic lubrication by geared pump plus sprash lubrication and lubrication bv oil
Main bearings and rods All important parts are of i)hospher brou/^e alloy also oilless metal and bait bearings
Oil \'iscosily: CS 20.62 at .37.8'<'
Capacity: 8tX)-l.OOOcc.
Needle bar stroke 24nim
Needle DCxl {—11. i;14, ::16) for overlock stitch
DMxl3 (-11, -14, i 16) for double chain stitch
Feed regulator I'ush-button t\ pe. scale on face plate represents stitch length
Differential feed Hy lever moving in vertical directions: gathering and stretching can be obtained even
regulator in sewing operation.
Knives Upper knife: L-shaped carbide tipped
Lower knife; flat shaped steel
Installation Semi-submerged (.Machine head is installed on the bottom board on which cushion can
support machine head. Only oil reservoir is located below the table top.
Feed regulator
Differential feed
regulator
Knives
Installation
Of this machine, there are the following sub-classc^s available.
- 1 -

SUB-CLASS LIST AND EXPLANATION ON THE MEDALLION
BROTHER INDUSTRIES IT
MADE IN JAPAN
Overedge biglu
Needle gauge
Sewing width
Sub-class
\ -2\ \
-3C — 5C
Needle gauge
2mm \
3mm
5mm
Overedge bight
3mm \N.
5min
5mm
Sewing width
5mm \N.
8mm
10mm
No. of needles
2 \ \ 2 2
No. of threads
A 5 \5
B 4 \4
Differential feed ratio
1.5-0.7 \ 1.5-0.7
1.5-0.7
Needle cooler
Equipped
Equipped
Equipped
Use For thin work
For medium work
P'or medium heavy work
2. Features
The extensive design of various components and lubrication system and also the addition of the needle cooler
device on this model assure
the normal operation of maximum high speed of 6,000 stitches per minute, without
any troubles.
A) Combined lubrication system of forced lubrication by geared pump, sprash lubrication and oil wick lubrication.
B) Unique design of needle bar mechanism has lessened its weight as well as ensures forced lubrication to its
every working part.
C) Exclusively designed over looper mechanism has made the use of light alloy possible and also ensures smooth
lubrication to the end.
D) Holders are made of duralmin to decrease weight. Main rods and bushings are made of phospher bronze alloy.
E)
Major moving parts are perfectly lubricated inside the totally enclosed main body, so they will never be
exposed to outside dusts.
*The upper knife is L-shaped to make the threading and replacement of the needle easy. Besides the carbide
tip promises long durability of the knife.
*Stitch can be easily regulated by push-button, with the scale on the face plate, thus it is unnecessary to change
the eccentrics when you would like to change the stitch length.
*Differential feed can be easily adjusted by the lever for gathering or stretching without soiling your hands.
This also applies for the instantaneous differential adjustment obtainable.
*Durable chain stitch looper's movement in forward-backward direction can be adjusted to obtain the proper
amount of clearance between the looper and needle according to the size of needle.
* Thread tension of the double chain stitch looper can be easily adjusted without opening the cover.
* Ample space on the cloth plate allows easy sewing operation and if you want, double chain stitch with edge
cutting work can be obtained without using the overedging mechanism.
*Oil level in the oil reservoir is shown on the special oil gauge on the front side of the machine.
*Lubrication can be easily checked through the oil window in the top cover.
*Needle cooler device ensures perfect sewing operation even with synthetic materials and threads at the high
speed of 6,000 stitches per minute.
* Colour combination of TAN-BEIGE is in well harmony with your modern factory, and operator's atigue can
be lessened.
* As differental radio can be adjusted up to 2.5, this is suitable for sewing of cloth which is ease to spread
such as knitted fabric.

3. Operation
A. Sewing speed
Maximum speed of this machine is 6,000 stitches per minute. For the first 100 actual working hours, however,
the new machine should be operated at about 5,000 s.p.m. so that all the working parts are well run-in. After
this running-in period, you may operate the machine at maximum speed of 6,000 stitches per minute. This is
desirable for machine's long life.
B. Motor, motor pulley and belt.
1) Use a clutch motor, 1/2 Hp, 2 pole, single or three phase. Our motor available is Models
MD-344 (single phase) and MD-354 (three phase)
2) Use M-type V-belt.
3) Machine speed (s.p.m.), diameter of motor pulley and length of motor belt is related to the following table.
Outside diameter of pulley and length of V-belt
Stitches per minute
50 Hz 60
Hz
Pulley
V-belt
Pulley
V-belt
5,200
115mm
39inch
95mm
38inch
5,500
120 " 39 "
100 "
38 »
6,000
130 » 39 " 110 » 38 "
C. Setting up
This machine is normally set up as semi-submerged type.
Necessary parts and accessories for setting up this machine are contained together with the machine head.
If you have purchased this machine as head only, make the table top as per attached table sheet, also refer
to Fig. 1, which shows the parts necessary for setting up this machine and also the measurement to mount the
bottom board to the table top as semi-submerged type.
With our Brother clutch motor. Models MD-344 and MD-354, there is no anxiety to set the machine to the
bottom board, however, if you would use with other brand clutch motor, please make sure to have proper holes
on the bottom board. 18.4 Centre of V belt
! Screw for cushion base
7^
Bolt hole for bottom board
Collar for bottom
board
Bottom board
Figures are in milimeter (Fig. 1
3 -
Centre of machine
pulley
Cushion base

D. Oiling, draining and maintenance.
Oil is drawn out of the machine prior lo its shipment.
Before operating? the machine, therefore, remt)ve the oil filter cap (shown
in Fig. 2) and pour oil into tlie machine using the funnel.
Oil level should be up lo the upper line of the oil gauge shown in Fig. 3.
1 he oil reservoir consists of two lacks partitioned by a filter, so it takes
sometime before the oil levels of both tanks match. Check if oil is up
to the required level a little after the oil is poured. Add oil if oil level
is below the upper line of the oil gauge.
Be sure to check the oil gauge for oil level before operating the ma-
-Oil
(Fig. 4}
When operating the machine for the first lime after unpacking it or
after it has been out of oil for a long period of time, add o or 6 drops
of oil into the oiling points shown in Fig. 4. and 5. ^'ou do not have to
add oil into them if the machine is operated daily.
At
the end of 100 hours actual operation, running-in period, change the
oil. Thereafter, change it once in about three months use.
The quantity of oil required is about 80()-1.000cc. Remove the screw
shown in Fig. (5. for draining oil.
\
The machine enq^loys a geared pump for the forced lubiication to its
major moving parts. It is recommended that the t)il reservoir be dis
mounted about twice a year for cleaning of its inner surfaces, pump,
wire gauze, etc. This is desirable for long life of the machine.
(Fig. 2)
BR01
(Fig. 5)
(Fig.
6)

E. Needle cooler device
With machine model C", it is equipped with the needle cooler device.
In order to get the good sewing result on the synthetic materials and resin treated materials such as polyester,
jersey, and tricot, etc., or with the synthetic threads, such as Nylon and Dacron, it will he advantageous to use
the needle cooler device.
1. Operating procedure
1) Pour the silicone oil into the lank approxiniEitclv 4/5 in capacil\' ,, . a
^ f I T b
(oOcc in
capacity) then open the cock shown in Fig. 7. w v
2) If this machine is brand new or after it has been out of use for long —m —ilT .jf
time, it takes about 10-15 minutes to saturate the silicone oil into the
felt on the needle guard, then apply several drips of silicone oil {in
the felt so as to thoroughly saturate before sewing operation. B
3) The cock must be closed when the machine do not reciuire the silicone
oil, namely on the slow speed operation or cotton thread, cotton ma- , '
terials applied and also when you do not use the machine. BROTHER |
2. Sewing capability with needle cooler (Fig. 7)
When \'ou would sew the synthetic materials, jerse\'. tricot, etc., it can be ensured to sew upto 6 plies of such
materials at the high speed of 6,000 stitches per minute.
3. Silicone oil to be used
Siljcone oil \'iscosity; .oOOcs
50cc silicone oil could be operated ajjpro.ximately half a month of sewing operation although it depends on the
sewing work.
4. Proper installation on the machine
Overlook
stitch
needle \
guard
Aligning
Overlook stitch
needle guard
Double chain
stitch looper /
Double chain
stitch needle guard.
Vinyl tube
Please be careful not to contact
Double chain
stitch needle
guard
' {Fig. 8) (Fig. 9)
1) The top of the felt must be aligned with the top of the groove of over looper needle guard.(Fig. 8)
In this case, please be careful to set up so that the double chain stitch looper may not contact to the tube.
2) Position of tank
The position of the tank should be set up at the position that the Vent hole is higher than the oil level as shown
in Fig. 7.
3) Removal of the top cover
(Fig. 10)
When you pull the tube Point A to the left as per Fig. 10, the tank and fell portions will be separated, thus
the tank can be detachable together with top cover.
- 5 -

F. Machine operating direction
The proper opcratiag direction of this machine is clockwise as viewed from the pulley side.
G.
Installing needles
Turn Ihc pulley until the needle bar is raised ^
to its highest position, lower the lifter level , '/
®shown in Fig. 11, pressing by the thumb \
finger and move the presser foot arm ffi' to . W U=J
the direction as indicated with arrow mark. i, \ f-Plll D®K—
Now, loosen the needle set screws and holding f^J^\ ® (W^L—
the needles with their grooved side facing | \ ^
toward you, then insert them into the needle (\ W >'|
clamp holes all the way up checking the holes »,
in the needle clamp whether these needles are ^ •- '• I
all the way up. After this check, tighten the l-V,''V. '•
Hole
Needle set screw
(Fig. 12)
H. Threading
Pass the threads through the eyes of the cotton stand then please do in the following order; 1. Under looper
2. over looper 3. double chain stitch looper 4. overlook stitch needle 5. double chain stitch needle.
Before passing these threads, open the front cover, cloth plate and thread take-up cover, turn the pulley until
the needles are at the highest position, and move the presser foot arm outward. Pass the threads as shown
in Fig. 13.
(DUnder looper thread
@ Over looper thread
@Overlock stitch needle
(D Double chain stitch needle ^
thread
(Fig, 13A)
For five threads
(Fig. 138}
For four threads
When you thread to the eyes of thread guides, loopers, and needles, please use with the tweezer in the ac
cessory box.
(Note)
Draw out the thread approximate 5cm from the tip of looper.
Care should be taken for threading of four threads and five threads because of difference between both cases
as shown in Figure ISA and 13B.

I. Stitches
(Fig- 14)
For five threads specification,
parallel stitching of 1)12 and F13
combination is arranged upon
adjusted (Figure 14). but rearrange
ment parallel stitching of D12 and
K13A combinalion(Figure I5)could
also be accomplished upon adjust
ment with turning the adjusting
(Fig. 15)
In case of the F13/D12 combination,
the over looper needle thread and
double chain stitch needle thread
have the strongest tension, followed
by the under looper thread tension
and then the over looper and double
chain stitch looper threads tension,
For four threads specification,
parallel stitching of D12 and F12A
combination (Figure 16) is arranged
upon appropriate adjustment.
J. Thread tension
Thread tension may change depending on the type of thread and material
positions of the thread take-up and thread guides. If it should change co
following manner
1. Adjustment of thread take-up
Needle thread will be ease to be tightened if the thread take-up is
lowered and be ease to be loosened if the thread take-up is raised up
on the contrary. J
The thread take-up in the middle position is the standard thread tension. I
(Fig. 17) f
Figure A will be applied to a thread take-ui) for five threads specifi- i
cation, and Figure B will be applied to a thread take-up for four threads i
specification.
2. Adjusting double chain stitch needle thread guide: K
To tighten the needle thread, raise the double chain stitch needle thread ft
guide. To loosen it. lower the guide The guide in the middle position I
is the standard thread lension.(Fig 17) I
(Fig. 16)
In case of the FI2A / D12 or
E13A/D12 combination, the double
chain stitch threads tension remain
the same, however, the overlook
stitch thread's tension must be
changed. In this case, the under
looper thread has the strongest ten
sion. followed by the
over loojDcr
thread tension and then overlock
needle thread tension.
sewn, stich width, stitch length the
isiderably. make adjustment in the
Thread take-up
(Fig 17)
Fig
.-X

3. Adjusting looper thread take-up and thread guide for overlock stitch :
oper
read takf-up ^
♦ ..
Looper
'|hread tak^up ^
a9/2-2C-
(Fig. 18) (Fig. 19)
As shown in Fig. 18 at the highest position ol' the needle, it is the standard position of the looper thread take-
up and thread guide, for the three threads overlock stitch.
In this case, the position of under looper thread guide shows in B is for cotton ihi'ead and A for synthetic thread.
As shown in hig. 19, at the highest jjosition of the needle, it is the standard position of the looper thread take-
up and thread guide, for the two threads overlock stitch.
4. Adjusting looper thread take-up and thread guides for double chain stitch :
As shown in Fig. 20. at the highest iiosition of the needle, it is the
standard position of the double chain stitch looper thread take-up and | Machine Body
Thread Handler
thi'ead guides.
Double chain
thread'°aK-up lowest point of the
thread taKe up guide's hole is in
level with top of looper
thread take-up
5. Adjusting thread tension screws:
After completion of the above-mentioned adjustment of the thread guides and thread take-up. turn the thread
tension screws for fine adjustment.
Incorporate an appropriate adjustment for the above "stitches" (Page 7).
He careful not to turn the screw in or out exce.ssively. because it may tighten the threads more than neces
sary or cause the thread take-up to feed (he threads too excessively
K. Adjustment on the pressure of presser foot :Installing or removing feed dogs • and Height
of feed dogs: ^
'iM t I r , , . Presser foot io I
1he pressure ol tiie presser fool can he adjusted h\' means of the adjusting screw m
presser foot adjusting screw shown in Fig 21 \
Tig. 22)
(Fig 21)
Follow llie instructions given below to install or remove the feed dogs:
(Fig. 22)
To install the differential feed dog "S'. tighten the screw ®.
'Ik) install the mam feed dog C'. tighten the screw 0.

Ihe standard height of the feed dogs is such
that when the overlook needle point comes to
a point 1 mm to top surface of the needle
plate in its upward travelling, the top of the
feed dogs is level with the surface of the
needle plate. (F'ig. 23)
Overlook needle
Surface of needle plate
L
(Fig.
23)
L. Adjusting stitch width (overedge bight)
Stitch width is dependent on cloth trimming width and the tongue of the needle plate.
Upper knife
(Fig. 25)
(Fig. 24)
Surface of
needle plate
0.5-0.7
Lower knife
Adjust the trimming width as follows: (Fig. 24)
1) Remove the upper knife.
2) Tighten the set screw 0 temporarily so thai the lower knife may come to the point where desired trimming
width may be obtained.
3) Loosen the screw (B) and adjust the contact of the upper and lower knives as shown in Fig. 25 by moving
the upper knife holding block to eith-^r left or right.
4) Tighten the screw (3 and install the upper knife while pressing it to the lower knife.
5) Loosen the set scrow (0 and please make sure that the lower knife may contact with upper knife by the
spring pressure.
Fix the lower knife by tightening the set screw (0).
- 9 -

M. Adjusting stitch length
(F'9. 26) (Fig. 27)
Stilch length can i)e adjusted to any point within the fange from 1.7min to 3.6m]n. At first, open the needle
thread take-up cover /V (Kj^. 26) Then, with the push-button (Fig. 27) located in front of the machine kept
depressed, turn the pulley slowly in the normal operating direction. The push-button goes inward as the |)ulley
is turned. Stop the pulley when the pointer reaches the number representing \'our desired stitch length, and
lelease the push-button. Ihe numbers indicates the stitch length, however, the actual stilch length may change
depending on the kind of the materials, their thickness and differential feeding.
N. Adjusting differential feed.
Differential feed ma\- be adjusted to stretch, be normal or gather by
loosening the screw A shown in P'ig, 28A and moving the lever up or
down as required. Normal feed is obtaind by setting the lever's mark ^
is in line with the mark on the scale. If the lever is lifted up. namely
stretching. After adjustment is completed, please make sure to tighten
the screw A secureK'. EC^oB
In the case to require larger gathering differential feed.
Kemove cloth plate and feeding mechanism cover, h)o.sen nut A of main
feed link shaft by an attached wrench, then lowei" downward. (Figure 28B)
When the main leed link shaft is lowei'ed until bottoming, the diffei"-
enlial ratio will become as follows.
Differential adjusting lever, upper end Differential ratio, 2.,").
Differential adjusting lever, lower end Differential ratio, i.d.
When a medium differential ratio is recjuired. place and settle the main
feed link shaft at an intei'inediate position in the groo\'e of main feed
:Fig. 2S.\)
Main Feed Link Shaft
Main Feed Arm
(Fig. 28B)

4. Adjustment
A. Height of needles (Pig. 29)
For needle replacement, please follow the chapter describing the correct
installation of the needles. When the needles are at the highest position,
the overlock needle should be 11.0 mm over the surface of the needle
plate, and at that time, the double chain stitch needle, about 7.8 mm.
B. Relation between needle and under looper (Fig. 30)
When the under looper is its left extremity, the distance between the point
of the under looper and the centre of right needle is 4.0 mm.
'1 he under looper is determined its height when it is inserted all the way
into the looper holder. The relation between the point of the under looper
and the needle in its upward travelling is shown in Fig. 30.
When the point of the under looper is going to pass the back of the
needle, which is in its downward travelling, the clearance between needle
and point of the under looper is
about less than 0.1 mm.
The under looper should be installed as being provided 1.5mm of inclination.
C. Installing needle guard (for overlock stitch) (Fig. 31)
Push the needle with the needle guard to such an extent that when the
point of the under looper comes to the centre axis of the needle on its
way up, they are barely out of contact with each other and install the
needle guard in that position.
D. Matching needle guard and needle, (for overlock stitch) (Fig. 31)
Use the needle guard and needle in the following combination.
Needle guard
Size of needle
Wo. 2
Sll
No. 31?14,
#16
No. 4
#18, #19
11 —
{Fig. 29)
about
78 mm
4
(Fig. 30)
labout
-.-Pressing needle with
needle guard
(Fig. 31)

E. Relation of needle with under looper and over looper
A clearance of about
O.I mm is desirable,
but slight contact can
be permitted.
Under looper
Overlook needle
Over looper
Needle must pass below
bulge on under looper
without contact
(Clearance. About 0 1mm)
(Fig. 32)
11 mm
Surface o
I needle plate
(Fig. 33)
After determining the relative position of the needle
and under looper mentioned in B, position the over
looper properly as shown in Fig. 32. & 33.
Mg. 33 shows the measurement of the over looper
setting, for your reference.
F. Relation between needle and double chain stitch looper. (Fig 34 35)
Needle eye
. 1. clearance
(Fig. 34)
(Fig. 35:
When the double chain stitch looper is at the left e.xtremity, the distance between its point and the centre of
the needle foi double chain stitch is about 2.0 mm. At that time, the double chain stitch looper should be set
with the clearance of about l.o mm between recess portion of the looper and needle plate holder
Ihe loopei is deteimined its height when it is inserted all the way into its holder The relation between the
double chain stitch looper and the needle eye on its upward travelling is as shown in h'ig. 35.
1 here should be as little clearance as possible between needle and looper point when the point is going to pass
the back of the needle on its way up.
— 12

G. Installing double chain stitch needle guard (Fig. 36)
Install the needle guard in such a position that when the looper passes
the back of needle as the needle rises from its lowest position needle
guard may not contact the needle pressing lightly the needle by finger.
If the correct adjustment is not made, skip stitch or needle breakage
may be caused when sewing on materials pulling or in case of sewing
folded part.
H. Installing and maintenance of knives (Fig. 37)
Mount the lower knife to the lower knife holder so that its edge is in
level with the needle plate. Install the upper knife so that its front
edge is 0.5—0.7mm below the edge of the lower knife when it is at
the lowest end of its stroke as shown in Fig. 37.
The upper knife is fitted with a tungsten-carbide tip, which cah be
ground only with diamond grinding wheel. It lasts its original sharpness
for a long period without re-sharpening. Sharpen the lower knife when
necessary. Fig. 38 shows the shape of lower knife.
13 —
Surface of kw
needle plate Pressing by
\ .^-"^finger
(Fig. 36)
Surface of
needle plate
0.5—0.7/flw
(Fig. 37:
(Fig. 38

5. Trouble shooting
A. Thread breaks
Cause
Remedy
Poor thread quality.
Use thread of good quality.
Thread too thick for needle size.
Change needle or thread for the right one.
Needle groove or needle eye poorly finished.
Change needle for a good one.
Excessive pressure of tension disc.
Adjust to proper pressure.
Needle improperly fitted. Refer to
instructions for "Installing needles."
(Page 6)
Needle, looper, needle plate, or thread passage
has flaws.
Smooth surface with oil stone or buff.
Relation of needle with looper and thread take-
up not right.
Refer to "Thread tension." (Page 7)
Wrong threading.
Refer to "Threading." (Page 6)
Needle gets hot.
Use with needle cooler or use smaller size needle.
B.Skip stitching
Cause
Remedy
Wrong threading.
Refer to "Threading." (Page 6)
Point of looper out of shape. Reshape
with oil stone or replace.
Needle point blunt or bent.
Replace.
Needle improperly fitted. Refer to "Installing needles." (Page 6)
Relation of needle with looper and
thread take-
up or clearance between them not right. Refer to
"Thread tension" and "Adjustment."
(Pages 7 & 11)
Needle and needle guard out of proper relation. Refer to "Installing needle
guard." (Page 11)
Needle gets hot.
Use with needle cooler or use smaller size needle.
Pressure of tension disc too small.
Adjust to proper pressure.
C. Needle breaks
Cau.se
Remedy
Needle and needle guard out of prc^per relation.
Refer to "Installing needle guard",
"Matching needle guard and needle" and
"Installing double chain stitch needle guard."
(Page 11)
Needle and looper out of proper relation.
Refer to "Relation between needle and under
looper" and "Relation of needle with under looper
and over looper." (Pages 11 & 12)
Needle bent.
Replace.
Needle imporoperly fitted. Refer to "Installing needles." (Page 6)
14

D. Imperfect chaining-off
(overlook stitch)
Cause
Remedy
WroiiK threading. Refer to
"Threading." (Page 6)
Stitch tonjjue on needle plate has flaw. Smooth with emery paper and polish with buff.
Looper thread take-up and thread guide out of
position.
Refer to "Thread tension" (Page 7)
Chain feed dog improperly installed. Refer to "Adjustment on the pressure of presser
foot: Installing or removing feed dogs: and Height
of feed dogs." (Page 8)
Threads too tight. Adjust to
proper tension.
(Double chain stitch)
Cause
Remedy
Wrong threading.
Refer to "Threading." (Page 6)
Needle thread and looper thread have tension
too strong or too weak.
Adjust to proper tension.
Differential feed
dog not in level with main feed. Refer to "Adjustment on the pressure of presser
foot: Installing and removing feed dogs: and
Height of feed dogs." (Page 8)
Needle thread guide out of position. Refer to
"Thread tension." (Page 7)
Lower thread take-up out of timing. Refer to
"Thread tension." (Page 7)
E. Improper thread tension
Cause
Remedy
Relation of needle with looper and thread take-
up not right.
Refer to "Adjustment" and "Thread tension."
(Page 7 & 11)
Tension disc will not work properly. Clean tension disc of foreign particles to allow
smooth operation.
Thread too thick for needle.
Use needle or thread of the right size.
Wrong threading.
Refer to "Threading." (Page 6)
F. Poor trimming performance
Cause
Remedy
Lower knife worn out.
Re-sharpen.
Upper and lower knives installed improperly.
Refer to "Installing and Maintenance of knives."
(Page 13)
Spring pressure on lower knife not right for
materials to be trimmed.
Refer to "Installing and Maintenance of knives."
(Page 13)
15

G. Irregular stitches
Cause
Remedy
Wrong threading.
Refer to "Threading." (Page 6)
Thread irregular in thickness.
Use thread of good quality.
Thread passage rough.
Smoothly polish.
Thread take-up and thread guide out of position.
Refer to "Thread tension." (page 7)
Knives blunt.
Refer to "Installing and Maintenance of knives."
(Page 13)
Lower knife installed improperly.
Refer to "Installing and Maintenahce of knives."
(Page 13)
H. Excessive wrinkles along stitches
Cause
Remedy
Differential feed needs adjustment.
Refer to "Adjusting differential feed." (Page 10)
Pressure of presser foot not right.
Adjust to proper pressure.
Thread tension too strong.
Adjust properly.
Feed dogs installed improperly.
Refer to "Adjustment on pressure of presser
foot: Installing and removing feed dogs: and
Height of feed dogs." (Page 8)
Knives blunt.
Refer to "Installing and Maintenance of knives."
(Page 13)
Cloth trimming width and stitch tongue of needle
plate out of proportion.
Adjust trimming width to needle plate or replace
needle plate.
Needle too thick.
Use needle proper for materials and thread.
1. Needle produce too large holes
Cause
Remedy
Needle point blunt.
Replace needle.
Needle too large for materials.
Use smaller size needle.
Needle gets hot.
Use needle cooler.
16 —
N

PARTS LIST for MA4-B972
INDEX
Paris. Nil.
(KlMin .P(Mr
002670 (i-14
K.-f. Nil. Kiiiiiirk
Paris. .Nil.
Kif. Nil.
Remark
Parts. .Nil.
/. 28
C 47
1)11
"
1(K).541 04)2
1IK)54T(|.()2 K .26
A 5
i KIO T
110821.001
1108:52.r).()l
'
(ill
1(M).579.04)2
l>-21
(xi.'ieao-?).!
(K)9()69-312
(M)9670ni4
1)10
(;.5
C 82
l(KK)44.()0.1
l(MK)454|.():i
1111275 04)1
1 A 84
1 K 70 '
" (1 55 - -
1111044)4)1
1114^001
009670516 A UK)
101.5.52.04)1
H (12 1
009671 (i 02
C 19
101.5724)4)1
ZIO
009680.8 12
00968 toil
(K)968I-2^'
Mill
A .20
"l>.87
101706.04)1
A.4.5
1)26
i 11 .54
• - -
iiMnoiroi
11186.54)01
11225)7
009682()-M
()69689-4 I2
009711()I2
A.22
11.62
024
101795.().()1
ll)2.5:i8.().(Kl
1()2629.0(H
Z:22
A 19
Z 9
Jj22!)7.0 16
1122994) 01
1122()()4).()|
ni27r)0.6l4
oi7751-4 12 K .1)7
C 16
1: 45
10271(14102
1026i204H
(1 .57
^10
11
112:5(6 1)^01
112.2.184) 111
017771-4.12 1) 14
1) 22
11.16
11)42154)4)1
1044.m) 4)1
104.521 ool
1-: .V.
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1)27
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11.5.2
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1 12
C 51
104651.04)1
C 46 1
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A-16
112.551 0 III
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11 12 1122.59.04)1
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26
10I908 0.01
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26
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1121(17.0 01
021770-1.02
K 12
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15.22
112421 ().()2
022710 |.02
1-; :!5
l(l.5()794)()l 15 19 11
1291 ool
021080 1 06
z :i5
105122.04)1
(111
1144474)01
025080 2:16
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1051624)4)1
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025.^50.2:{2
II .VI
105172.04)2
11 46
IMIKl 41 01
()28080.2.42
z:ii
10.5228.0.()1
(i-.59 11601611 01
021451 6.02 Z 24
105220 04)1
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116221.0.01
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0480.50.3.47
1 .21
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(•180 116778.04)1
048080 3 46
p.:i()
105242()0l
Z 2 «
(kl81.501.42 1)11)5
10.5:t44 0 01 Z 8
117127 11.02
072600 0.20
11:!()
10.58274)01 C-JO
117127114)1
081004 0.70 1 29 106069.1)411
C 25
11716(1 0481
1(KM)16.()4)2
11 49
-P .29
117515 1101
1000254)4)1
l).|(Mi
1(811291)01
P. (11 1175164)4)1
1(100:12 OOl
A 40
11 .55
IIMi812.00l
107092 l).02
Z 25
1) 108
117I1(16.|).()I
1(KK)25()()2
(ill
1) 112
l(KK)8().().():i 1: :21
107'22l 4)4)1
P*..VI 118.527 I) 01
1(K)I2().().()1 A 18
10724 l ()4)l
15 .52 -
•P 12
107272()()2
A 28 12082:51)01
i(K)i:i7.().()i
11 19
1()7:{5I 001
15 59
M(8):i2.ooi
l(K)i:i7.0.()2
A.18
l()7.t()7()4l2 1) 86
M(8):52.l).ll|
-11 61
107491 •04)2
Ci 17
M(M):«1.|).01
l(K)127.().o:i
(:.18
107779.0.01 Z 5
M(8):S7.(I.()2
100176 04)1 I-; 1 108721 •() 1)1 (1
27
MI8):S8.(I02
1(K)185 ()4):i
A 21 -(1 ;55 1400:594)4)1
A .55 -(1 (12
14(8140 (1 III
- 111 l()8<Ki2.() 01 Z 41 14(8)11(101
-11 11 Z
19 1418)12(101
1IK)18.5.().()1 A 51
1(I92()2()01
A.89
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A.()2
109.574.0.01
I >79 M(8).|8.(l.()()
«A
4)9 lOlK-MlOOl
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11(8Ti|.(l.()2
•A 71
1101(11.0.(12 P .28 14(8).5.5.().()1
-
A.7.5
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l(8).564l 4)1
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78
1101614) in
1) 2
1100.57.0.01
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(12
110191 04)1
1 -211
1100.58 4|.()1
-Cf 9
1104.26.001
Z 1 MOOdOOOl
•
(•.21 110495 OOl
All 140062.(101
•
(;..52
110641.04)1
A .90
14(8M14.(|.()1
"1
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110671.().(K)
15-19 Mn065.(|.01
-1 20
110668.04)1 15..K)
MIMMMlnOl
100215.0 00
1) 109
110670.048)
15-18
110067.(14)1
100242 0 02 All
1106724)48) 15 .V)
14(8)71.04)1
100251.04)1 |).95
1106734)48) 15 51
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100260 04)1
11 4
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15 15 140075.0.01
100264 0.04 11416
K 10
1400774)4)1
100289()01
C 2 -V.
22
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100289.0.0:1 C.28
11071)4.0.01
CO 14(8)84 O OO
100.366001
11 9 c
.:i5
14(8)85.0.02
n
11.1:1 110706001
C 14
140088.04)1
•K 21
110720.04)1
K.22 140089.04)1
100368.002
1147
1107.254) 111 A 8
140090.0.01
100469 0()2
A.56
110778 0.01
Kl
140091.0 00
100539.00:1 1)51
11079.24)4)1
p.32
140092.04)1
1(X)54I.0.01 11-20
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140093.04)1
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110094.001
100541.0 02
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A-52
Kcniiirk
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MOIOI
MO n-
MO (Mi
l-iOIOH
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Mono
Moni
Mon
1011 5 0 01
MOIMOO
MOllo'O'Ol
MOIKi'O'lH)
MOI 7-0 1)
MOI IS'O'INI
Momoiii
MOlliO-OOl
MOll'lOOl
M(n22-0-01
M0121-0(ll
M012:.0))l
I 10127 IIOI
M0128-0()l
M012<>'0<>l
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Moi;!;i ool
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Moi:;<i II 111
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Mill II IMIl
M0M2 IMI]
MOMIMI'IH)
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Mlll.TIMIINI
Moir.l o m
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I4II1800III
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1018-I00
40I8ri4)IK)
M018(i4)4MI
I0187()()0
140188 0 0.t
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14011KMI4I1
140194101
1401920 01
140194(14)1
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1401974)4)1
140202 04)
402024)4)1
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11)2074)4)1
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):t6.:t7

INDEX
Parts. No.
Ref. No.
Remark
Parts. No. Ref. No.
Remark
Parts. No. Ref. No.
Remark
Parts. No.
Ref. No.
Remark
140212001 D-16
140727-0-01 A-101.102
143179-0-01 B-40
14,52840-01
1}-95~113
140213-001
D-19
140736-001 K-1
143182-0-01 B-41
145285-0-01
D-101
140214-0-01 D-18
140738-0-01 Z-31
143280-001 J-18
M5286-0-O1
D-99
140215-0-01
D-44
140739-0-01
Z-.32 «
L-5
145288-001
D-107
140216-0-01
D-43
1407,56-0-01
G-65
1432820-01
1,-5
145289-0-01
1)110
140217-0-01
D-46
1407.58-0-01
A-91 '
K-17 1
145290 0 01
D-111
140226-0-01
D-58
140759-0 00 Z-17
143284-0 01
A-58
145638-0-01
B-68-72
140228-0-01
D-4
140764-0-01 11-3
•
1,-5
145640-0-01
B-71
140229-0-01 D-5
140768-0-01 11-23
14:1286-0-01 G -64
14,5651-0 01
B-73
140230-0-01 E-21~25
140771-0-01
i)-:ii
143287-001 D-60
145663-0-01
D-113
140231-0-00 E-22
140772 0-01 U-41 1
143292-0 02
A-21 1
145664-0-00
A-103
140232-0-01
E-24
140774-000
C-,5,3 1
143293-0-01
A-IB 1
146195-001
180323-0-01
1 8-:i5
140233-0-01 E-25
140774 0 01 D-30 1
14.3294-0-02
A-95 1 C
-2.3 ,
140235-0-00 E 66
140775-001
D-56 1
143296 0 01
K-13 1"C.27.28 i
1)26.27 1
140236-0-01 E-68
140778 0-01
11-19
14.3297-0-01 0-114
181995-0-01
140237-0-01
E-63
140779-0-01 11-28
143312-0-00
B -31
403387-0-01 1)85 1
140238-0-01 E -64
140780-001
11-6
14332:10-01
E -51
40:1865-0-02
G-16 1
140239-0-01
E-62
II-7
143324-0-01 E -50 1
508693 0-01
11-47 1
140240-0-01
E-60
»11
20
143325 0 01 E -52 1 1
140241-0-01 E-59
140781-0 01 11-8
143326-001
E -49 I 1
140242-0-01
E-61
.
11-24
143374-001 A-101 11
140243 0 01 E-58
140782-0-01
11-16 1
143375-001 A-.54 11
140244-0-01
E 50
140792 0 01 Z-23 114,3442 0-01 i E -69 j
1402460-01 E 39
140798-0-01
Z -21 1
143524-0-00
B-.32
1
140247-0-01 E-54 1
140888-0-01 E-11 1
143,5,31 0 01 11-10
j
140260-0-01
E -28
140910-001
1 -1.3
14,35:16-0-01
A-:i()
140261-0-01 K -27
140912-0 01 J13
14:1537 0-00 A-29
1
140262-0-00 E -31 1»
K-12
143538-0-01
A-57
i
140263-0-01 E-25 1
140913-0 01 A-19
143,550-0-01
A-72
140264 0 01 1 K-24
140928 0 00 0-25
143564-001 0-33
1
140266 0 01 1 p-9 :
140989 0 01
140990 0 01
E- 1-9
143,565-001
U-20
1
1 K-.3 E 4
14.3566001
Z 4
140267-0 01 1 I'M
140991-0-01 1 E-5
14.370.3 0-01
A-104 t
140268-0-01 K-3~11
440992-()(>l
140993-0 01
E 7
14.37O.I-0-0I
A-105 I
140269-0 01 K-9 E.8
• • E^W
1437:1:1-0-01
C-29
C-i2
1
140270-0-01 K-:i
140997-001
14:1734-0-01
i
K-8
14118:10 01 A 43
143757-001
G-IS
t
140271-0-01 i K-10
1411880.01
0 12 i
Z.I2 '
1437.580-01
C-18
1
140272-0 01 ; K -6
142125-0 00
14.3768-001
143774-01)1
" 1437820-oT
G-4.5 !
1 K-1I
142126 0 01 B-.3.3 i
A-80 ,1
1402730 01 f K-1
142127001 J-1
A-79
I
K-6
142182-001
A 64
r Jll
14.3783-0 01 1,-3
s
140274-0-01 j K-4
142198-001 14:1850-0-01 E -71
14027.5-0-01 1 K-2
1-12201-0-01 i 1,-1 1
1-1.3991 0.02 1 A-98
1 K-7
142229-0 01 1
1-30
I" J3 i
• J-IO
14:1992-001
A-99
140276 0-01 1 K-5 142241001
1440.53-0 01
1440.55-001
1440.56001
144079001
1)102
1)1(13
140277-0 01 K-37
142243-0 01
140278 0 01 C,
40
C-ll
142244-001
J -7 1) 104 1
140281-0-01
142245 0-01 J 8 1--
.44
!
»<:
19 142246001 J 5 1-14080 001
1-14081-0 01
1.140820 01
I" 17 !
«
<;-22
1422I7-0O1 1 J -1
- -
E -48
140286-0-01
14224900I
, J 14
' .1-3 10 I-
-43
140289-0-01
C-K)
1-t22.50 00l
1422.51-O-OI
14408:1001
E -54
140290 0-01 (1-56
i J -9
1)96 1
' 1-16
144084.0.01
141085001
1-- -12
1
140291-0 01
(:-.5.3
142260001
1" -46
i
140292-001
(:-5i
14228100I
144086 0 01
M l088 (Mi l
144103.001
E 45 1
140293 0 01 1 (:-48 1422820 01 1-11
E .55 1
140294 0 01 : C-dO 14228-I001 1 -19
G-72.76 '" ^
140295-0-01
(:-46
M2292O01
1 17
1 "1
14410-10 01 (:-71.75
1402g<;-0-01
A-50 1
142314 0-01
114J[0.5O()1
144106-0-01
G-70. 74
!
140298-0-01
(:-i7
142316-001
ll2:il 8 0(10
G-69.73 i1
140299-0(11
(:-.55
H -42
1 1-18 j
1 -22
1-141()8 0 ()1 1 G -79
144109.0 01 1 G-78
1
140300 0-01
140305-0 01
142321-0O1
i-r232:t"oor !
11-.58
1 1 -32
1441100 01
G-77
G.67,68
j
140313-0-01
E -3 1 1 J -20 1
144112 0 01
149314 0 01
11-14
1 K-18 1441170(XI E.7.3
140317-0 (K) : K-27 i
142329000 1 1-14 i
1441.10 0 (XI I :i,5
E -72
1 -:i.i
K-ii)
J -21'
1 -.31
149320-0-00 i H-10 1
142:1,300 01 1
-28
z-:io
1441780(11
140325-0-00
11-4 1
1423:H-001
142:{40 001
Ml 1830.(11
140326-0-01
n-6 1
A-79
Ml 1810 (11
» H-23 1-12:14:1-001 1 Z-15
144185.001
»I
-10
142370-001 , J -1.5
1441860 (Ml
140327-0-01
n-18 1 I-I2371001 1 J.16
J-22
»
C-4 1
142412-0 (X) 1 -8 .
K-20
1
1 C -40 142574-0 01
o-:i8
0.54
1)13
14422.5001
Z-16
1
140342-0-01 Z-2 ! 142.5880-01
1.1.1:119000
K 21
11-49 6.3
I
140414-0-01 C-15 1
142.589 0-01
142590 001
1146170.01
140415-0-00
B-21
C-7 1
M.16180.(M)
_M-i(>19 (J.()0
M462().(I01
11-57 1
140416-0-00
C-42
«
c-:i:i
11 51 1
140417-0-00
A-68
-E-7 1
11-55
n .56
1
*
C-43
-
1M9
1446210.01
144622-0.01
1
140418-0 00 B-5
'
1-: -:io 1
11-52
1
140419 0 00
C-22
14266900I ! (M.l
M462:iO.(X)
II 60
!
140420-0-00
D-15
14267:iO(X»
0-93
144624-0 00
1161 i1
140421-0-01
A-71
142674-0-00
0-94
M4625-().(X)
11-62 !
140423 0-01
B-27
1I2787001
I -24 1
141699-0-00
J -2.3
140456-0-01
J-12
142!)79-0-01
Z-.36
144779-001
G-81
r——
140468-0-01
11-59
14,3151-0-01
1.-2
14488.1.0-01
A-100
140708 0-00
C-11
14317:1001
B-38 M497.3-(l-()1
E;41
z-9:i
"
C-37 i 14,3174-001
B.37 1
14.5277001
1
— 18 —
rs