Yamato CZ8000 User manual

Thank you for purchasing the Model CZ8000 class.
Before using your machine, please read the instruction
manual and understand the contents well.
After reading the instruction manual, please keep it in a lo-
cation where it is easily accessible to the operator.
CZ8000 class
SUPER HIGH SPEED OVERLOCK
Instruction Manual

CONTENTS
Safety instructions ⅰ - iv
1. Name of each part 1
2. Installation 2
2.1 Semi-submerged type 2
2.1.1 Table cutting diagram 2
2.1.2 Installation 3
2.2 Motor, pulley and belt 4
2.3 Hanging belt 5
2.4 Belt cover 5
2.5 Eye guard and 󲥬nger guard 5
3. Sewing speed and rotating direction of pulley 6
4. Lubrication 7
4.1 Lubricating oil 7
4.2 Lubricating 7
4.3 Changing oil 8
4.4 Checking and replacing oil 󲥬lter 8
5. Proper operation 9
5.1 Needle system 9
5.2 Installing needles 9
5.3 Adjusting thread tension 10
5.4 Pressure of presser foot 11
5.5 Releasing presser foot 11
5.6 Opening cover 12
5.7 Adjusting differential feed dog 12
5.8 Adjusting stitch length 13
5.9 SP device and HR device 14
5.10 Cleaning the machine 15

CONTENTS
6. Adjustments of sewing machine 16
6.1 Needle thread tension for overlock stitch 16
6.2 Looper thread tension for overlock stitch 17
6.3 Width of overedge seam 18
6.4 Upper and lower knives 19
6.4.1 Height of lower knife 19
6.4.2 Height of upper knife(󲥭at type) 19
6.4.3 Sharpness of knives 20
6.4.4 Sharpening knives 20
6.5 Height of feed dogs 21
6.6 Needles and loopers 22
6.6.1 Height of needle 22
6.6.2 Installing angle of lower looper 23
6.6.3 Distance between needle and lower looper 23
6.6.4 Front-and-rear position of lower looper 24
6.6.5 Parallel of needles 24
6.6.6 Distance between needle and upper looper 25
6.6.7 Back and forth position of upper looper 25
6.6.8 Timing relation between lower looper and upper looper 26
6.7 Needle and needle guards 26
6.7.1 Needle and needle guard(rear) 26
6.7.2 Needle and needle guard(front) 26
6.8 Position of presser foot 27
7. Specifications 28
Attention
The parts used for this product are subject to change without notice. If such a change is made, any part
of the contents and illustrations of this instruction manual may not conform to this product.
In preparing the instruction manual, we have made our best efforts for making it free of any error or
omission. If any error or omission should yet be found, it might not be rectified immediately.
Attention
◇This instruction manual is designed mainly for technicians, but it is advisable that also operators read
the instructions with mark to use the machine properly.
◇The numbers in lower left corners of figures are figure numbers. We use them in texts as needed for
your reference.

i
SAFETY INSTRUCTIONS
The sewing machine, automatic machine, and attachments (collectively called“the machine”below) involve
sewing operations that require the operator to be near moving parts of the machine. Because of this,
there is always a potential danger of unintentional contact with the moving parts. For this reason, the
operators who actually use the machine and the maintenance staff who perform maintenance and repair must
carefully read“2. Basic precautions”and“3. Precautions to be taken in various operating stage”below
and fully understand this information before operating or maintaining the machine.
The information contained in the“Safety Instruction”of this manual also includes items not found in
the product speci󲥬cations.
To assist in better understanding this manual and the product warning labels, warning indicators are
categorized as shown below. Be sure that you fully understand the contents and carefully follow the
instructions.
1. Safety Instruction
1.1 Explanation of risk levels
DANGER
This indication is given when there is a danger of death or serious injury if
the person in charge or any third party mishandles the machine or does not
avoid the dangerous situation when operating or maintaining the machine.
WARNING
This indication is given when there is a potential for death or serious injury
if the person in charge or any third party mishandles the machine or does not
avoid the dangerous situation when operating or maintaining the machine.
CAUTION
This indication is given when there is a potential danger of medium to minor
injury or damage of the sewing machine if the person in charge or any third
party mishandles the machine or does not avoid the dangerous situation when
operating or maintaining the machine.
1.2 Explanation of pictorial warning indications and warning labels
There is a risk of injury if contacting a moving section.
There is a risk of a burn if contacting a high-temperature section.
There is a risk of electrical shock if contacting a high-voltage section.
Connection of an earth cable is indicated.
The correct direction is indicated.
Explanation of safety label
① There is the possibility that slight to serious injury or
death may be caused.
There is the possibility that injury may be caused by
touching the moving part.
② Perform sewing work with safety cover.
Perform sewing work with safety protection device.
③ Be sure to turn the power OFF before carrying out
“threading,”“needle changing,”“bobbin changing”or
“oiling and cleaning.”
①②③
Explanation of high-voltage warning label
High voltages are 󲥭owing inside the power supply of the control
box. This indicates that there is a risk of electrical shock.
When it is necessary to open the control box containing
electrical parts, be sure to turn the power off, remove the power
plug and wait for at least 󲥬ve minutes before opening the cover
in order to prevent an accident resulting in electrical shock.

ii
SAFETY INSTRUCTINONS
Explains the symbols used in the instruction manual.
Failure to follow the instructions can result in an injury or damage to the machine.
Be sure to follow the instructions when you operate, check, adjust or repair the machine.
Never do this.
Be sure to remove the power plug from the source of the power supply, when checking, adjusting
and/or repairing the machine or when there is the possibility that lightning may strike.
Additional explanations and notes, etc., for operation or adjustment
1.3 Explanation of symbols
2. Basic precautions
1. Be sure to read this instruction manual and
all the other explanatory documents supplied
with accessories of the machine before using
the machine. Always keep the instruction manual
where it is easily accessible for the operator
and maintenance staff.
2. The content of this section includes items which are
not contained in the speci󲥬cations of your product.
3. Be sure to wear safety goggles to protect
against accidents caused by needle breakage.
2.1 Applications, purpose
Our industrial sewing machines have been
developed in order to increase quality and/or
productivity in the sewing industry.
Accordingly, never use our products for other
than the intended use as described above.
2.3 Safety devices and warning labels
Be sure to operate the machine after verifying
that safety device(s) are correctly installed
in order to prevent accidents caused by lack
of the device(s).
With regard to safety device(s), please refer
to page vi.
If any of the safety devices is removed, be
sure to replace it and verify that it works
normally in order to prevent accidents.
Be sure to keep the safety label and/
or warning lables attached to the machine
clearly visible in order to prevent
accidents. If any of the labels has become
stained or come unstuck, be sure to replace
it with a new one.
2.2 Working environment
The environment in which our industrial sewing
machines are used may seriously affect their
durability, functions, performance and/or safety.
Do not use the machine in the circumstances below.
Places of high ambient temperature and/or
humidity that seriously affects sewing machines.
Outdoors, places of high temperature or in
direct sunlight.
Environments containing dust, corrosive or
󲥭ammable gases, or in contact with chemicals.
Where the voltage 󲥭uctuation range is more
than ± 10% of the rated voltage.
Location where suf󲥬cient power is not available
for the power supply capacity of the controllers
and motors that is used.
Near objects where strong electric or magnetic
󲥬elds, such as high frequency welding
machines which make noise, are generated.
As dew condensation may occur when suddenly
bringing the machine from a cold environment
to a warm place, in order to prevent accidents
caused by breakage or malfunction of the
electrical components, be sure to turn the power
on after waiting for a suf󲥬cient period of time
until there is no sign of water droplets.
When lightning occurs, be sure to stop operation
and remove the power plug in order to prevent
accidents caused by breakage or malfunction of
the electrical components.
2.4 Instruction and training
○ Operators and workers, who supervise, repair or
maintain the machine head and/or machine unit,
are required to have the adequate knowledge and
operation skills to do the job safely.
○ The manager should plan and enforce the safety
education and training of those operators and
workers beforehand.
2.5 Modi󲥬cation
Never modify and/or alter the machine in
order to prevent accident that can result in
personal injury or death. Yamato assumes no
responsibility for damages or personal injury
or death resulting from a machine which has
been modi󲥬ed or altered.

iii
SAFETY INSTRUCTINONS
3.1 Unpacking
Be sure to unpack the machine from the top.
If the machine is packed in a wooden crate, be
careful of the nails. Remove the nails from
the board.
Never hold the parts near the needle or
threading parts when removing the sewing
machine head from the buffer of the box.
Removing and carrying the sewing machine head
should always be carried out by two or more people.
Take out the machine very carefully while
checking the position of the center of gravity.
Preserve the cardboard box and packing material
carefully in case secondary transport is
needed in the future.
Disposal of the packaging
The packaging material of the machine consists
of wood, paper, cardboard and polystyrene foam.
The proper disposal of the packaging is the
responsibility of the customer, and must be
properly disposed of in accordance with the locally
valid environmental protection regulations.
WARNING
2.6 Items for which the power to the machine
has to be turned off
Be sure to immediately turn the power off if
any abnormality or failure is found or in the
case of power failure in order to protect
against accidents that can result in personal
injury or death.
To protect against accidents resulting from
abrupt starting of the machine, be sure to
carry out the following operations after
turning the power off.
● When threading to the parts such as the
needle, looper, spreader, etc., or when
changing the bobbin.
● When changing or adjusting all component
parts of the machine.
● Adjusting the stitch length
● Adjusting the differential feed ratio
● When inspecting, repairing or cleaning the
machine or leaving the machine.
○ Be sure to remove the power plug by holding
the plug section instead of the cord section
in order to prevent electrical shock, earth-
leakage or 󲥬re accidents.
○ If the machine is using a clutch motor, to
protect against accidents resulting from abrupt
starting of the machine, be sure to carry out
the above operations after verifying that the
machine has stopped completely, since the
motor continues turning for a while even after
turning off the power supply switch.
3 PRECAUTIONS TO BE TAKEN IN VARIOUS
OPERATING STAGES
Disposal of the machine waste
The proper disposal of the machine waste is the
responsibility of the customer, and must be
disposed of in accordance with the locally valid
environmental protection regulations.
The materials used in the machines are steel,
aluminum, brass and various plastics.
A specialist should be commissioned if necessary.
3.2 Transportation
Be sure to take suf󲥬cient safety measures to
prevent falling or dropping when lifting or
moving the machine.
If the machine and/or your hands are stained
with oil, the machine may easily fall to the
󲥭oor. Therefore, wipe off the oil carefully.
To prevent accidents during transportation,
repackage in the same state as the original
delivery packaging.
Be particularly sure to fully wipe off
any oil adhering to the machine before
repackaging.
The machine head should be carried by two or
more people.
The machine should be carried by people
only when moving to the table or transfer
hand truck, and all other transportation
operations should use a hand truck. When
moving to the table or hand truck, be
careful that the machine is not subjected to
excessive impact or vibrations. Otherwise the
sewing head could fall over.
When handling the machine, do not carry the
bottom part of the cloth plate cover.

iv
SAFETY INSTRUCTINONS
3.3.2 Wiring and grounding
Never connect the plug for power supply until
assembly is 󲥬nished.
Also, be sure to avoid the usage of multiple-
outlet extension cords in order to prevent
electrical shock, earth-leakage or 󲥬re
accident.
Fix the connectors securely to the sewing
machine head, motor, and electric apparatus.
Also, when unplugging the connectors, hold
the connector part.
When wiring the connection cords, please take
care of the following.
○ Connect the cords away from the driving
parts.
○ Do not apply excessive force to the
connection cords.
○ Do not bend the cords excessively.
Never use staples to fasten the cables. Otherwise
it may cause a short circuit and/or 󲥬re.
Arrange the ground wire securely to the designated
position on the machine head.
Also, wire separately from the grounding for
other equipment.
3.3.3 Handling machine oil
Keep machine oil out of the reach of children.
Be sure to 󲥬ll or add lubrication oil to
sewing machines before operating them.
Use “Yamato SF oil 28” as speci󲥬ed.
If machine oil gets in your eyes, it may
cause eye in󲥭ammation. Always wear protective
glasses to prevent the oil from getting in
your eyes.
*Should machine oil get in your eyes, wash
them with fresh water for 15 minutes and
then consult a medical doctor.
If oil adheres to your eyes or body, be sure
to immediately wash it off in order to prevent
in󲥭ammation or irritation.
If oil is swallowed unintentionally, be sure to
consult a medical doctor in order to prevent
diarrhea or vomiting.
Methods of disposing of waste oil and/or
containers are speci󲥬ed by law. Dispose of
it properly as required by law. If you have
further questions on its disposal, consult
the place of purchase.
After opening the oil container, be sure
to seal it to prevent dust and water from
getting into the oil and keep it in the dark
to avoid direct sunlight.
Do not store in high-temperature areas or
areas exposed to an open 󲥭ame.
3.3 Installation, preparation
3.3.1 Machine table
Prepare a machine table (table board and legs)
that has suf󲥬cient strength to withstand the
weight of the sewing head and any reaction
while operating.
Securely join the table and legs to ensure
suf󲥬cient strength to withstand the weight
of the sewing head and any reaction while
operating.
○ Maintain a comfortable working environment
with consideration of the lighting and the
arrangement of sewing machine to enable the
operators to work smoothly.
○ Adjust the height of the table according to
the posture of the worker.
Also, when installing the control box and the
related parts on the sewing machine, make
sure not to affect the posture of the worker.
If casters are 󲥬tted to the table stand, be
sure to use high-strength casters with a
locking mechanism.
Lock the casters except when moving the machine.
WARNING
3.4 Before operation
○ Never put your hand under the needle or near
the moving parts of the machine when turning
on the power supply switch.
○ When operating a new sewing machine, make
sure the rotating direction of the pulley
agrees with the rotating-direction mark.
○ Before turning the power on, visually check
the cables and connectors for conditions such
as damage, disconnection and/or loosening.
○ If a table stand with casters is used, be
sure to secure the table stand by locking the
casters or securing the legs with adjusters,
if provided, in order to prevent accidents
caused by abrupt moving of the machine.

v
SAFETY INSTRUCTINONS
WARNING
3.6 Maintenance, inspection and repair
○ Maintenance, inspection, and repair must be
performed by staff that have received special
training and fully understand and follow the
information in the instruction manual.
○ Be sure to turn off the power supply switch
and make sure the sewing machine and motor
completely stop before the maintenance,
inspection, and repair. (If the machine is
using a clutch motor, take care that the
motor keeps turning for a while even after
turning off the power supply switch.)
4. Recommended check points for maintaining
machine performance
(1) Perform regular cleaning of the machine parts
by following the instruction manual.
(2) Perform regular inspection of the lubrication
oil by following the instruction manual, and
re󲥬ll or replace the oil as required.
(3) Because the oil-proof parts use rubber, their
oil-proof performance is reduced over time.
○ If the seals or other stationary parts
fall off or begin to lose their sealing
performance, replace them with new parts.
○ The replacement period for parts used in
the movable sections varies depending
on the machine operating conditions,
environment, maintenance, and oil used,
but replacement every several years is
recommended.
(4) For details about the replacement procedure,
please contact your local dealer or Yamato.
WARNING
3.5 During operation
○ Be sure to operate the sewing machine using
the safeguards such as belt cover, 󲥬nger
guard, and eye guard.
○ Never place your 󲥬nger, hair or objects under
the needle or close to the moving parts while
operating the sewing machine.
○ Be sure to turn off the power supply switch
when threading or replacing the needles.
○ Never place your hands close to the knives
(upper and lower knives) when operating the
sewing machine with the trimming devices.
○ Be sure to turn off the power supply switch
when terminating the sewing work or leaving
the sewing machine.
○ In the event of the power failure, be sure to
turn off the power.
Also, if the sewing machine malfunctions,
makes abnormal sound or emits unusual odors
while operating, be sure to turn off the
power supply switch.
○ While operating the machine, wear clothing
that cannot be caught in the machine.
○ Do not put any tools or other unnecessary
objects on the machine table while running
the machine.
○ If a clutch motor type is used, it will
continue running for a while even after the
power is turned off. Therefore, be careful
because the machine could start running by
pressing the machine pedal.
○ If a servomotor is used, the motor does not
produce noise while the machine is at rest.
Be sure not to forget to turn the power off
in order to prevent accidents caused by
abrupt starting of the machine or motor.
○ To prevent entanglement accidents in machines
with a puller mechanism, keep your hands,
hair, and clothing away from the machine.
○ Do not attempt to modify the machine at your
own discretion. We are not responsible for
accidents caused by such modi󲥬cation.
○ Use genuine Yamato parts when repairing the
machine and/or replacing the parts. We are
not responsible for accidents caused by any
improper repair/adjustment and substituting
other parts for those manufactured by Yamato.
○ Turn off the power supply switch if removing
or replacing any parts or during adjustment
of the sewing machine.
○ Be sure to also remove the gasket if the
cover is removed for maintenance, inspection,
and repair. If the gasket is not removed, the
edge of gasket may cause injury.
○ Do not pull the cord when removing the plug.
Be sure to hold the plug itself.
○ A high voltage is applied inside the control
box. Turn off the power supply switch and
wait for at least 󲥬ve minutes before opening
the cover.
○ Be sure to replace the safety devices and/
or safety covers if removed for maintenance,
inspection and repair.
○ After performing maintenance, inspection and
repair, make sure that turning on the power
does not pose any danger to you.
When operating the machine for the 󲥬rst time
after work is performed, run at low speed to
check for abnormal sounds or other problems
before performing high-speed operation.

vi
SAFETY INSTRUCTINONS
Belt cover
The belt cover prevents entanglement with the
belt.
Do not operate with the cover removed.
Front cover
The front cover prevents contact with the
moving parts inside the cover.
Do not operate with the cover opened.
Eye guard
The eye guard prevents injury to the operator’
s eyes due to breaking of needles during the
sewing operation. This section also houses
the needle thread take-up, upper knife, and
other moving parts.
Do not operate with the eye guard opened.
Finger guard
The 󲥬nger guard prevents the operator’s 󲥬ngers
from going under the needle. However, there
is some space at the top of the 󲥬nger guard
and other sections, and so there is a risk of
󲥬nger insertion.
Do not operate when the 󲥬nger guard is removed.
Cloth plate
The cloth plate prevents contact with the
moving parts inside the cloth plate.
Do not operate when the cloth plate is opened.
Safety label, warning label
Reaf󲥬x the labels if they start peeling off or
become dirty and illegible.
Cloth plate
Eye guard
Front cover
Finger guard
Safety label
Belt cover
5. Safety devices and warning label affixing locations

1
CZ8000
1. Name of each part
Fig. 1-1
Oil cap
Presser foot
Drain hole screw
Cloth plate
Presser foot
release lever
Finger guard
Oil reservoir
Eye guard
SP device
(behind Eyeguard)
Thread tension
spring cap
Front cover

2
CZ8000
2.1 Semi-submerged type
2.1.1 Table cutting diagram
2. Installation
Fig. 2-1
Center of crank shaft
Center of machine pulley
operator
Installing hole for motor
Table dimensions 1200
×
540
×
40 mm
Section X - X
Section Y - Y
Section Z - Z
Refer to the instruction man- ual of the motor for dimen- sions A, B, C, and D.
3×φ9 . 5

3
CZ8000
2.1.2 Installation
Install the machine correctly referring to Fig. 2-2 and 2-3.
Table 1 The number of spacers ① and ②
Size of spacers : ①=15㎜ ②=5㎜
Fig. 2-3
2. Installation
③
②
①rubber
cushion
Fig. 2-2
③
④
supporting board
rubber cushion
①
②
⑤
⑥
⑦
chute (upper)
support
chute
④
supporting
board
machine table
Thickness of
tables Number of ① Number of ②
40 ㎜ 4 4
45 ㎜ 4 not necessary

2. Installation
4
CZ8000
Use only those motor pulleys applicable to the machine.
If not, the sewing speed will be over maximum and the
machine will be damaged.
2.2 Motor, pulley and belt
See the instruction manual for the motor to use and install
the motor properly.
To install the clutch motor, align the center of the machine
pulley with that of the motor pulley when the motor pulley
shifts to the left by toeing down the pedal.
NOTE: Table 2 shows the outside diameter of the motor
pulley, sewing speed of the machine, and size of
the belt when using the clutch motor of 3-phase,
2-pole, 400 W(1/2HP).
The outside diameter on the table shows the near-
est size to the calculated values based on the com-
mercial pulleys at intervals of 5 ㎜.
Fig. 2-4
Table 2
V-belt of M-type
Servomotor:
Calculate the outside diameter of a motor pulley from the
formula as below.
Or see Table 3 to select a proper motor pulley diameter.
Outside diameter Usual sewing speed
of motor pulley Servomotor speed
= × 48.5 + 5 mm
Table 3
Belt
Use a V-belt of M type.
For belt size, refer to Table 2.
Outside
diameter of
pulley (㎜)
Sewing speed
of machine
(sti/min)
Size of belt
50Ｈｚ 60Ｈｚ Semi-submerged
90 6000 M34
95 6400 M34
100 6700 M35
105 5900 7000 M35
110 6200 7200 M35
115 6500 7500 M36
120 6700 7700 M36
125 6850 8000 M37
130 7000 M37
135 7300 M37
140 7500 M38
145 7800 M38
150 8000 M38
Sewing speed
of machine
(sti/min)
Outside diameter of motor
pulley(㎜)
rpm of servomotor
3000 rpm 3600 rpm
6000 102 86
6200 105 89
6500 110 93
6700 113 95
7000 118 99
7200 121 102
7500 126 106
7700 129 109
8000 134 113

2. Installation
5
CZ8000
10 - 20㎜
①
②
③
④
To prevent you from getting injured and a material from
being caught by the belt, be sure to install the belt cover.
2.4 Belt cover
(1) Install the auxiliary belt cover ⑤ as shown in the
󳊂gure.
(2) Install the belt cover ⑥ as shown in the 󳊂gure.
2.5 Eye guard and finger guard
To ensure safe use, ALWAYS install the eye guard ⑦ and the 󳊂nger guard ⑧ on the prescribed position dur-
ing operation.
2.3 Hanging belt
Use the V-belt of M-type.
(1) Hang the belt ① on the machine pulley ②, and then
on the motor pulley ③ while rotating the machine pul-
ley.
(2) Adjust the belt tension so that the belt has 10 - 20㎜
slack when its center is pressed with 10 N .
(3) Lock the motor with the adjusting bar ④.
Fig. 2-6
Fig. 2-7 Fig. 2-8
⑤
⑥
Before hanging belt, Always turn the motor switch OFF
and check that the motor has already stopped.
⑦
Fig. 2-5
⑧

6
CZ8000
If rotating in reverse direction, oil can not be supplied
properly, and the machine can be damaged.
3. Sewing speed and rotating direction of pulley
The maximum sewing speed is 8000 sti/min.
Run a new machine at speed about 15 - 20% lower
than maximum speed during the 󲥬rst 200 hours (for
about one month) so that a machine can offer a
long service life in good condition.
The rotating direction of the motor pulley ① and the ma-
chine pulley ② is clockwise as shown in the 󳊂gure.
Fig. 3-1
②
①

7
CZ8000
Too much oil or insufficient oil can cause oil leakage and
machine trouble. Be sure to keep the oil level between
the lines. Also too much lubrication can cause oil scat-
ter and material stain.
4. Lubrication
4.1 Lubricating oil
4.2 Lubricating
Use YAMATO SF OIL No. 28 or Mobil Velocite SM22.
When using a new machine or a machine which has not
been run for a while, supply few drops of oil to the needle
bar ① and the looper bar ②.
Remove the oil cap ③ indicated “OIL-IN” and supply oil
to the upper line of the oil sight gauge ④.
Make sure that the oil splashes from the nozzle inside the
oil cap ③ when running the machine.
If oil does not splash from the nozzle, see “4.4 Checking
and replacing oil 󳊂lter” on page 8.
Fig. 4-1
Fig. 4-2
Fig. 4-4
Fig. 4-3
③
④
②
NEVER add additives to the oil.
If added, it can cause the deterioration of the oil and the
damage to the machine.
①

8
CZ8000
Period :
When using a new machine, change the lubricating oil af-
ter running the machine for 200 hours (about one month).
After that, change the oil once or twice a year.
Procedure :
(1) Remove the belt cover. (See page 5)
(2) Remove V-belt from the motor pulley. (See page 5)
(3) Remove the machine from the machine table.
(4) Set a container under the screw ① to receive the oil.
(5) After removing screw ①, the oil will drain out.
(6) Reset the screw ①.
(7) Change the oil. (See “4.2 Lubricating” on page 7)
(8) Reinstall the machine on the machine table.
(9) Hang the V-belt on the motor pulley and reinstall the
belt cover. (See page 5)
Be careful the oil may spill out from the oil filter ②,
when loosening the screw ④．
4. Lubrication
4.3 Changing oil
4.4 Checking and replacing oil filter
◆ If the oil 󳊂lter ② is clogged with dust, lubrication can-
not be done properly.
◆ Remove the oil 󳊂lter cap ③ and the oil 󳊂lter ② to
check them every six months. If clogged or cracked,
clean or replace the oil 󳊂lter.
◆ If the oil splashes from the nozzle insuf󳊂ciently or in-
cludes many bubbles even though oil is suf󳊂ciently kept,
check or replace the oil 󳊂lter.
Fig. 4-5
Fig. 4-6
②
③
④
Be careful not to soil the V-belt and the machine pulley
with the oil.
①
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9
CZ8000
5. Proper operation
5.1 Needle system
5.2 Installing needles
CZ8000 class : DC×27 (or B27, 1886)
Select proper needles in size according to the thickness
and the type of the material. Table 4
Fig. 5-1
Fig. 5-3
Fig. 5-2
NO OK! NO OK! NO
Tighten the screws ① with a tightening torque of 0.6
N･m.
Before installing the needles, ALWAYS turn the mo-
tor switch OFF and check that the motor has already
stopped.
(1) Loosen the screw ① with a minus screw driver. (Fig.
5-1)
(2) Remove the old needle with a pair of tweezers.
(3) Insert a new needle into the needle clamp ② as far as
it goes with facing its scarf to the right back. (Fig.
5-2 and 5-3)
(4) Tighten the screw ① with the minus screw driver.
● Accessories include the minus screw driver.
②
①
front
Japanese
standard 8910 11 12 13 14
Metric
standard 60 65 70 75 80 85 90
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5. Proper operation
10
CZ8000
5.3 Adjusting thread tension
Adjust the thread tension with the thread tension spring
caps ① - ④ according to the type of fabric, the type of
thread, seam width, stitch length, and other sewing condi-
tions.
● To tighten the thread tension, turn caps clockwise.
● To loosen the thread tension, turn caps counterclock-
wise.
Fig. 5-4
Threading
Table 5
③
②
①
Loosen
Tighten
Before threading, ALWAYS turn the motor switch OFF
and check that the motor has already stopped.
Improper threading can cause thread breakage, skip
stitch, and uneven stitch.
Threading correctly by referring to the threading 󳊂gure
which is attached on the back of the front cover.
ATTENTION
④
Model
Thread
CZ8003
single needle
overlock
CZ8020
2-needle
overlock
Left needle ① ①
Right needle ②
Upper looper
thread ③ ③
Lower looper
thread ④ ④