Not a vintage machine but,
 

maybe someone can help me. I have a White Superlock serger that will not sew, it did, but now the handwheel will only turn one revolution, and it will go back the same distance. Since it won't continue to turn, it won't sew. Everything else seems to be moving fine. I don't need it to sew well, tension and all of that, I just need it to work so I can use the cutter. Any ideas or suggestions, or should I just pitch it! TIA

Maybe time for a trip to the sewing machine repair shop?

I have one of those on the bench right now (model 534), that's doing the exact same thing. I've drenched it with WD-40 (which usually works), but it still binds in the same spot. The gears are metal, so it's not a broken gear. The last one was the lower blade shaft (right in the front) that was frozen. The previous one was the big, round eccentric that you can see from the open bottom of the machine.

They're an alright machine, but they don't have differential feed, and they can't sew through 4 layers of Jersey knit. I have one at home, but had to buy a Bernina (Juki) so I could sew those 4 layers of stretchy fabric for my home business.

It's worth opening up and trying to find where it's binding.

Yes, Annette, that's the model # and I have taken the bottom off and looked and from what I can see it seems to be at the handwheel, which I can't see. If you find what it is, please let me know. Thanks for responding.

I'm hoping to talk to the boss about the White serger tomorrow morning. I'll let you know what he says.

Did you take the right side panel off? You can get to the belt and motor from that side.

I couldn't figure how to get it out of the "sides" to get it clear of the handwheel. I didn't want to apply too much pressure for fear of cracking it.

I have had this serger since 1987 and would not part with it. Just in case it comes up with the same malady as your's, I will be watching to see what the cure is. The biggest problem I've had was in changing the knife and not seating it properly. I quit taking it in for yearly service when I realized the techs were blowing the case clean and oiling it. At that time the charge was about $89 for the service.

OK, I didn't take the cover off the gear box. There IS a nylon gear in there! Here's a picture. The Boss says it would cost the woman $38 for the gear and $90 labor. It's not a fun one to change out. He sold her a used Bernette for $150, instead.

Well that's put paid to this one. Thank you so much Annette for all your help.