Welcome To SIRUBA

◎ The needle thread is too tight/loose.

Check：

Is the tension of the needle thread too loose or too tight?

Adjustment：

Please adjust the tension of the needle thread.

------------------------------------------------------------------------------------------------------------------------

◎ The skipping stitches of the needle thread.

Check：

Choose the wrong needle?

Adjustment：

Select the correct needle and thread number that fits the fabrics.

Check：

Bad needle?

Adjustment：

Replace with a new needle.

Check：

Is there any clearance between the needle and the top of the left looper?

Adjustment：

Adjust the clearance between the left looper tip and the needle to be ±0.

Check：

Does the small tension adjusting spring not function?

Adjustment：

(1) If the small spring does not function, pull it to be more tightened.
NOTE: the thread broken might occur if pulling the spring too tight.
(2) If there is any groove existing on the tension adjusting plate, please change a new one.

------------------------------------------------------------------------------------------------------------------------

◎ The skipping stitches of the needle thread.

Check：

Is the tension of the needle thread too tight?

Adjustment：

(1) Loosen the needle thread tension properly.
(2) Adjust the line (A) of the needle thread to the highest position, so that the released value of the needle thread from the thread hook (B) will be decreased.

------------------------------------------------------------------------------------------------------------------------

◎ The skipping stitches of the right looper thread.

Check：

Is the clearance between the right looper and the needle is too wide?

Adjustment：

When the right looper moves right backward, the clearance to the needle has to be 0.1 mm, which is using the correct right looper. (Each model has the most appropriate right looper for 1 needle, 2-needle, heavy materials, or light materials.)

Check：

Is the clearance between the right looper and the left needle is too wide when using 2 needles?

Adjustment：

Because of the correlation of the left/right positions while assembling the right looper and up/down moving positions of the right looper seat, adjust the movement path of the looper. When the right looper is descending, decrease the descending amount from the left to the right needle.

------------------------------------------------------------------------------------------------------------------------

◎ The skipping stitches of the left looper thread.

Check：

Does the right looper not hook the left looper thread while they are crossing each other?

Adjustment：

Change a new left looper. (When the left looper tip is worn and is to be adjusted/replaced, please do not grind or make the top of the left looper thiner.

------------------------------------------------------------------------------------------------------------------------

◎ Needle broken.

Check：

Choose the wrong needle?

Adjustment：

Use a thicker needle without having the pinhole on the fabrics.

Check：

Assemble the presser foot incorrectly?

Adjustment：

When assembling, make sure that the needle can insert into the center of the needle hole of the presser foot.

Check：

Is the height of the feed dog incorrect while assembling?

Adjustment：

Adjust the height of the feed dog teeth to be 0.8mm~1mm over the needle plate, and keep the proper pressure of the presser foot at the same time.

Check：

Bad threading?

Adjustment：

If there is any connecting part of the thread, please deal with it first before threading.

------------------------------------------------------------------------------------------------------------------------

◎ The needle tip is damaged.

Check：

Are the height positions of the right looper and the needle incorrect?

Adjustment：

When the needle is close to the upper dead point, push the needle forward a little to see if the needle tip touches the right looper or not. Then, adjust the height of the needle or the moving position of the right looper.

Check：

Is the needle guard too close?

Adjustment：

The needle guard inside must leave the needle before the left looper tip reaches the right side of the needle. The clearance from the front needle guard to the needle should be about 0.2 mm.

Check：

Is the assembled position of the needle plate incorrect?

Adjustment：

Move the needle plate forward a little to assemble in order to widen the clearance A a little.

------------------------------------------------------------------------------------------------------------------------

◎ Broken thread and rough/uneven stitches

Check：

Is the thread hold of the thread stand not polished?

Adjustment：

Use a piece of the emery cloth to polish the surroundings of the thread hole.

Check：

Choose the wrong thread?

Adjustment：

Replace with a better thread to balance the threads.

Check：

Isn't the thread adjusted correctly?

Adjustment：

Please be noted that the threads of the left/right looper should not be too loose. When adjusting the position of even one needle thread, related changes of the threads are needed to be noticed.
A. Pull the needle thread tightly→the left looper thread is looser→the right looper thread is looser.
B. Pull the left looper thread tightly→the right looper thread is looser→the needle thread is looser, too.
C. Pull the right looser tighter→the left looper thread is looser→the needle thread is looser.

Check：

Is the presser foot spring adjusted incorrectly?

Adjustment：

Adjust the presser foot flexibility to fit the fabrics.

Check：

Is the trimmer worn?

Adjustment：

Sharpen the trimmer edge or replace with a new one.

Check：

Does the differential ratio not match/fit?

Adjustment：

Adjust the differential feeding to match the feeding fabrics.

------------------------------------------------------------------------------------------------------------------------

◎ The thread does not come out when doing chainstitch.

Check：

Is the chainstitch looper cam adjusted inappropriately?

Adjustment：

Adjust the cam to an appropriate position.

Check：

Does the thread tension control device not function well?

Adjustment：

(1) Adjust the spring strength　
(2) Polish it or replace with a new one.

Check：

Is the presser foot rear spring not assembled correctly?

Adjustment：

Readjust the spring or change a new one to ensure that the presser foot can move smoothly and test its pressure.

------------------------------------------------------------------------------------------------------------------------

◎ The thin or thick thread is not able to distinguish.

Check：

Is the eccentric cam rusty?

Adjustment：

Clean the stock part, so that the oil can reach the cam.

Check：

Is the control spring of the eccentric cam not adjusted appropriately?

Adjustment：

Adjust the tension properly, but the tension should not be too loose.

Check：

Doesn't the slide block that cooperates with the stopper cam function well?

Adjustment：

(1) Correct the width of KP09D or polish the width of KP09D to make it narrower.
(2) Replace KP09D or KP06F.

------------------------------------------------------------------------------------------------------------------------

◎ Loud noise or strange noise.

Check：

Sound of the fabric plate?

Adjustment：

(1) Adjust the screw to the proper position.
(2) Adjust NK26 of KB06E to stablize the side cover of the fabric plate cover.

Check：

Is the main shaft loose and making noise?

Adjustment：

Clean the copper glue from the copper sleeve of the main shaft and readjust it.

Check：

Is there any crashing noise from the side cover of the fabric plate?

Adjustment：

Correct the angle of the side cover of the fabric plate to keep it from the lower looper and the upper trimmer seat.

Check：

Noise of the pump (scratchy sound)?

Adjustment：

Use a fixture to add pressure on the gear of the pump, and keep the pump running for about 3~5 minutes.

Check：

Is the needle bar loose?

Adjustment：

Replace a new one or polish the contacting surface to make the clearance smaller.

Check：

Is the fixed hook of the connecting rod that controls the clearance loosening or clashing?

Adjustment：

(1) Add glue onto the screw.
(2) Grind the groove to make it wider or chamfer.
(3) Replace it with a new one.

Check：

Is the position of the upper and the lower trimmers incorrect?

Adjustment：

Adjust the angles of the upper and the lower trimmers.

------------------------------------------------------------------------------------------------------------------------

◎ The oil does not splash.

Check：

Does the oil not come out from the pump?

Adjustment：

(1) Relock it to the correct position.　
(2) Reassemble the gear of the pump to the main shaft and adjust the position.

Check：

Does the upper mechanism not splash the oil?

Adjustment：

(1) Clean the lints and change the oil releasing screw.
(2) Change a new filter.
(3) Clean the dirts or replace with a new one.
(4) Use a piece of iron wire to clean the oil path through.

------------------------------------------------------------------------------------------------------------------------

◎ The trimmer is not sharp.

Check：

Is the trimmer not sharp?

Adjustment：

(1) Sharpen it or replace it with a new one.
(2) Correct the angles of the upper or lower trimmer seats.
(3) Reassemble it. (Assemble and adjust based on the norm standard)

------------------------------------------------------------------------------------------------------------------------