Baby Lock Serger Thread keeps breaking

Try rethreading it using the order: 3, 4, 2, 1. If you are threading it in the wrong order it will give you problems. Afterwards, you will need to carefully adjust the tension controls. This can be done more easily using four different colored threads.

Serger thread breaks

1. Is the serger threaded correctly?

2. Is the needles inserted correctly?

3. Is one of the needles bent or damaged?

4. Is the tension adjusted too tightly?

5. Is the tension adjusted to accommodate thickness of thread being used?

6. Are you using inferior quality thread?

7. Is the thread feeding off the cone/spool freely?

8. Is the needle size correct for the type of fabric being used?

9. Are the needles being used the correct one for the serger?

10. If all of the above suggestions don't help then the serger needs to be checked for a timing problem at a sewing machine repair shop.

Serger thread breaks
1. Is the serger threaded correctly?
2. Is the needles inserted correctly?
3. Is one of the needles bent or damaged?
4. Is the tension adjusted too tightly?
5. Is the tension adjusted to accommodate thickness of thread being used?
6. Are you using inferior quality thread?
7. Is the thread feeding of the cone/spool freely?
8. Is the needle size correct for the type of fabric being used?
9. Are the needles being used the correct one for the serger?

I suggest changing both needles
and rethreading the machine
use a can of air that is used for computer keyboards on the inside
here's a link for parts to the machine and also has a manual
the manual should have information about the thread tension
http://www.sewingpartsonline.com/babylock-BL90-serger-machine-parts.aspx

change the needle--flat side to the back of the machine
check to see if
1. bobbin is inserted correctly
2. are there any burrs on the needle plate or bobbin area
3. change thread--use every thread guide
name of machine & model number is not shown
if this is a baby lock machine then go to the website & contact customer service about a manual

You will have to order the manual from a Baby Lock dealer.

This model may have to be threaded in a certain order.

Try raising the presser foot and setting the tensions to zero.

Turn the handwheel so the upper looper (the curved one) is at it's highest position - there may be a mark on the side of the serger where you align the handwheel for this.

Thread the upper looper and then the lower looper and then the needles.

Pull the threads under the presser foot and toward the side of the serger.

Set the tensions back to 4 - 6, lower the presser foot.

Hold onto the thread tails and gently press the power pedal to begin a thread chain before serging fabric.

• the factory default settings are 4,4,4,4 and M
• Change the needles
• use a can of air spray ( compressed air can sold in computer stores) to ensure there is no fabric or dust under the needle plate

change the knife blades

My lower looper thread keep breaking, what is the problem.

I was in a similar position (but had the manual). The manual isn't as complete as I'd like. Anyway, what finally got mine working were the following:
1. turn all tensions to zero before putting thread through them
2. thread the upper looper, then lower looper, then needles.
3. when threading the lower looper (mine kept pulling out), after passing the thread through the looper eye, it needs to go pretty much straight up, not wrapping around anything else - other thread, for example. Mine was at one point trying to wrap itself around a post.
4.when everything is all threaded up, make sure all threads are under the foot *and* pulled to the left (even though the manual says pull to the back). Then chain off without fabric, turning the handwheel by hand to make sure loops are forming. If so, adjust tensions to where you think they should be (mine are currently all between 2 and 5), and add fabric. Then tweak as needed.

For me, this was a lot of trial & error, hair-pulling, and getting tips 1, 2, and 4. I figured out #3 on my own, with much swearing along the way. Good luck!

LF