I have a Juki DDL8700 Lock stich sewing machine. Does it require a Lockstich needle? I am having a problem with machine not sewing

A Juki DDL8700 uses a system 16 X 231 needle. You can buy them anywhere they sell industrial sewing machine needles. This number indicates the LENGTH of the needle. Then you will need to decide the weight of the material you are going to be sewing. Generally a Size 14 needle sews most items. If you are sewing a lot of jeans hems etc. you might go to a Size 16. If you are going to sew knits, buy your size 14 in a ball point needle to prevent skipped stitches. A home machine needle will not work in this machine. You thread this needle left to right so the needle goes into the machine with the thread hole sideways and not front to back. A Juki DDL8700 uses a system 16 X 231 needle. You can buy them anywhere they sell industrial sewing machine needles. This number indicates the LENGTH of the needle. Then you will need to decide the weight of the material you are going to be sewing. Generally a Size 14 needle sews most items. If you are sewing a lot of jeans hems etc. you might go to a Size 16. If you are going to sew knits, buy your size 14 in a ball point needle to prevent skipped stitches. A home machine needle will not work in this machine. You thread this needle left to right so the needle goes into the machine with the thread hole sideways and not front to back.