I once bought a machine and upon close inspection it had the wrong bobbin, wrong bobbin case and wrong needle and it had two completely different weights and types of thread. Poor baby. Ran great when all fixed. Keep at the process of elimination Dorothy and eventually you will have a trouble free machine.

Maybe you need a new bobbin case?

Sunflowerzz, I had read so many peoples' bad experiences of disassembling the tension unit that I was really leery of messing with it. I took it apart carefully following the book and cleaned all pieces. None were terribly grungy but all are nice and shiny now. Didn't notice any burrs or rough places on the interior pieces.First try at getting it back together didn't go well so have decided to take a break. A little time reading here and playing a couple of games of Words with Friends and I'll tackle it again.

Bearisgray, a previous poster had me check the bobbin case and there doesn't seem to be a problem there. The leaf spring is not bent and there are no burrs or rough spots. And at $40-$50 for a new one, I really don't want to put good money after bad on this machine.

You know, it's funny, but I have a habit of naming inanimate objects. The Singer 128 was Goody the moment I picked her up from Goodwill (not very inventive, I know). The 15-88 is Estelle for the aunt from whom I inherited her. Even had a car one time that had a bad habit of getting the horn stuck when the keychain clicker didn't work properly. Named him Horatio after Forester's Horatio Hornblower. But I've had this machine for three weeks now and it doesn't have a name. Guess that should tell me something. LOLOLOL

Last time I cleaned the lint out of my 301's feed dogs I didn't get the below "R" finger in the "O" slot correctly when replacing the needle plate. I remember the tension was bad and it did not improve regardless of bobbin case tension changes made or the disassembly and cleaning of the upper tension assembly. But, once I read the manual and saw that "R" was not in "O" and fixed that issue then all was fine.

Getting a tension back together is pretty simple - make sure the little pin is in the post and moving easily - a lot of times it can have a bit of gummy oil on it. If the little pin is gummy it won't push in and out right. Put things back in the right order per your diagram - pay attention to getting the bits in the right direction. Getting it adjusted at the end can take a bit of time but don't let the machine think you are in a hurry or are scared. I wish I could reach through my computer screen and do it for you. Most of the time I just pull the tension apart as I clean a machine and re-assemble. Most of the time is is pretty easy. It is also a good idea to pull the tension spring off the bobbin case, clean and re-assemble and adjust if you are doing a deep clean up on a machine. This manual should have a tension about like the 301 - look at the 201 with the numbered dial: http://www.tfsr.org/publications/tec...achine_manual/

Check to be sure the needle is set in the right direction. Have you made sure you threaded the needle in the right direction? Check your manual.

Thanks for the pic, Judy. I had that problem when I first started working with this machine. That is what I was talking about when I said "And the position finger is in place in the notch of the position plate."

Miriam, I have the tension unit back together all nicely cleaned up and shiny. I have been following the diagrams and instructions in the original user's manual. Tools for Self Reliance is a wonderful organization, isn't it? The thread follows the proper path for threading, ending at the needle where it goes from right to left. The needle is placed with the flat side to the left. Fortunately, at least according to the manual, that is fool proof as it will only fit in one way ;)

After working with the tension unit, the stitching is still exactly as it was regardless of how I set the top or bottom tension. The only thing I haven't done is disassemble the bobbin case and clean and reassemble it. Will wait until tomorrow to tackle that as I'm completely worn out at this point. I've been working on this for over two weeks, reading and researching and trying first this and then that with no good outcome. I'm not a quitter but this is about to beat me.

Oh, sorry Dorothy. I didn't read all of the text carefully enough. Good luck tomorrow with the debugging! :-)

I would take apart the upper tension assembly and make sure its cleaned. Then I would check my bobbin tension by holding the thread and pulling on it to see if it has any tension to to it at all. If that doesn't work, I don't know?

Thanks, redsquirrel. Got brave this afternoon and took the tension assembly apart, cleaned and reassembled it. Tried some test sews and various settings with no change from previous. Also have the bobbin tension set so that the unit will just barely move downward if I hold it by the thread.

I've never found anything mechanical I can't fix but this has me flummoxed.

Dorothy, the first Singer 401G I worked on took me about a year to make it work right. I worked on it. Gave up and went back to it again and again. It works beautifully and now I know a lot about Singer 401s, etc. Keep on with it. At least you have a manual and somewhere to turn for problems.

I had a 401 about a week ago that was giving me fits with it's tension. I replaced the tension and it was still doing it so it wasn't the tension. I looked for burrs & polished up some burrs in the throat plate and on the hook - that wasn't all of it. I took apart the bobbin case area and cleaned. That wasn't all of it. There was a slight adjustment on the spring that did some good. I set the tension real loose on both ends and then tighten a little at a time. Eventually it worked just fine. Some times you clean up a tension and it magically goes back together and works beautifully the first try. Some times not. Keep going on it.