Seiko Sth 8 Bld-3 Stitch Problem With Leather/vinyl

[Dude]

Hi all. Hope I am in the right topic section for this query. If not please forgive me and/or direct me to the proper topic area.

Recently developed a problem with my machine that is driving me crazy.

I cannot get the top stitch tight enough to draw the bobbin thread to the middle. I have even adjusted the top thread so tightly it starts to break when sewing. I have even loosened the bobbin thread to the point where the tension screw barely holds threads and still won't pull the bottom thread up. Further I have replaced the entire top thread tension assembly thinking there might have been something wrong or worn on my original. That made no difference. I am using #92 bonded thread and marine vinyl and upholstery leather.

I also have a Consew 206 RB-4 that works perfectly. I tried to simulate the tensions of the 206 on the Seiko but that proved futile.

Any help would be greatly appreciated. Thanks, Darryl

[dirtclod]

Found this after doing a search for your machine it may or may not help.

Since I use multiple thread weights on this I find it very helpful to keep scraps from cutting and use them to test the tension. Threading is not difficult but you do have to make sure it is done correctly. When I go through the tension discs I will “floss” with the thread to make sure it is in securely. When you pass the thread through the bottom disc (the one with the small wire on the left), make sure you pull upward until you hear a click. I didn’t do this initially and I had all sorts of issues which had me removing the 80 pound head and running it down to my dealer in a panic.