Having problems with lockstitch

[Sasho]

Hello, it's my first post and I didn't find a better section to post this if this is not the place excuse me. 

On topic 

I have a walking foot machine, a new one I have set it, but there's a problem occurring :

Whenever I try to lockstitch the thread underneath bunches up and is happening only when I reverse

Somehow the above thread is pulled under without any signs of other problems 

My forward/reverse stitches are perfectly matching

Upper tension and bottom tension besides this are perfect and in unison

I have played with the hook also to see if it's misaligned or out of time, but I don't see anything wrong with it

Have tried different size of needles and thread, but without any success 

Tried the tighten the top tension and its improving abit, but then the botton thread is showing ontop

Providing 4 pictures, last one is when I sew and then turn the fabric which makes a perfect stitch formation

I will be really thankful if you have any suggestions or have experienced similar problems 

 

[Northmount]

@Sasho Moved your post to leather sewing machines.

[kgg]

4 hours ago, Sasho said:

I have a walking foot machine, a new one I have set it, but there's a problem occurring

Any chance of providing some extra photo's showing how you have threaded the machine from the top thread spool to the needle, machine name and model number.

kgg