bkay

I'm using the 401a that I cleaned up a couple of months ago. The stitch length lever does not match the stitches per inch. Set at 10 SPI, I am getting 15 or so. It's not really a big deal, as I can just set it at differently. Still, though, I wonder what I missed cleaning as this one was really a dirty bird and took a lot of solvents to get everything moving again.

bkay

Mickey2

I don't know about the 401 but I know the 201 and 15 with stitch length lever can act up this way; and like many other issues it's can be caused by grime, dirt and sticky parts some where in the machinery. Sticky parts can take days to sort out (and I know you know it very well), it can be hard to identify exactly which it is. There should be adjustments for this and I guess there's something in the service manual. It should show sitches per inch very accurate. My 201 does but my 99 is not spot on the stitch.