Juki LS-340 Sewing Machine

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Juki LS-340

Serial #LS0YC03478

The LS-341N is a very similar model. The manuals can be used to set-up the LS-340 with only very minor differences. Currently scouting about for LS-340 IM and EM's.


This is a Juki LS-340 Cylinder-Bed 1-Needle, Unison Feed Lockstich Machine (with reverse).

I acquired this machine in mid-October of 2011. It was originally used for mobile baseball glove construction/repair at Major League Baseball games by a company that makes gloves and other sporting equipment. The machine had been sitting for a few years, but overall was in pretty good shape. It took a few hours of good solid cleaning to get the accumulated dust and grime off, and get everything properly lubed. A few inexpensive parts had to be replaced, such as the thread tension spring, the thread tension pressure discs, and thread feed post.

Subsequently I replaced the slip-clutch motor with a variable speed servo motor (so I actually had some control!), along with the thread spool stand and the bobbin winder (the latter wasn't *really* necessary, but the tensions discs and springs were rusty and a new winder assembly was all of $10), and some additional bobbins.

I've spend a number of hours on the 'net trying to track down original documentation. I found a copy of the parts book circulating, but it had 2 pages missing (the frame diagram and parts numbers). I recently acquired an updated version with all the pages present. Yet to be found is the Engineers Manual and Instruction Manual. I suspect somewhere in the dark recesses of a filing cabinet a printed copy exists, and if I could track it down, I'd scan it and make it available.

Based on a comment in the parts books, I think this machine is from somewhere around 1994. I've emailed Juki about some info on the machine and gotten some help (like the updated parts book), but no reply on the age of the machine based on the serial number.

I still have a lot to learn just how to use the machine, but I can get the needle and bobbin threaded, and with some trial and error with a given piece of fabric, get the tension set correctly. As for sewing a straight line, well, that's not really happening yet... I've actually had just as much fun getting it cleaned up, tuned up and running as actually using it. I can see why people get addicted to sewing machines :)

Equivalent Machines

  • Seiko CW-8B
  • Brother LS3-C53-050
  • Consew 227R-2
  • Highlead GC22618
  • Global WF975
  • Mitsubishi LY3-6840
  • Pfaff 345H3
  • Singer 153B8B


Needle Info