kgg

Thickness and most importantly breaking strength. The V92 has a breaking strength of 14.5 lbs. while V138 is 22 lbs. A good chart for needle and thread size selection can be found at ( www.tolindsewmach.com/thread-chart.html ). kgg

I looked at their website and didn't see what size and type of needle they supplied with their machines. For that machine the needle system needs to be a 135 x 16 for leather where as the 135 x 17 is made for fabric. I would suggest a buying V92 and V138 thread for your needs. A excellent thread made in the US and Canada would be American & Efird ( www.amefird.com ) which you can also get from places like Wawak ( www.wawak.com ) in either bonded nylon or bonded polyester. Bonded polyester offers better UV protection then bonded nylon. kgg

I am not familiar with a Singer 25KY needle. The needle from the info I have seen for that machine calls for a DDX1 needle system and for the thread V92 that you are using in a size #19 or #20 or #21 depending on how thick a material you are trying to sew. The needle needs to be inserted so the long grooves are on your left and the thread is threaded from left to right, Page 5 and 6 of the manual I have attached. kgg Manual Singer 132K6 Seiko SK-7 SK-8 SK-26 - II (1)-1.pdf

First what size thread are you using with what needle size and system? From the last photo it appears you have the needle in backwards. A better photo of how you have the needle installed would help. kgg

I have been following your progress from a barn find to a beautiful old iron machine and the job you have done is just excellent. kgg

Make a trip to a sewing machine repair / sales shop. kgg

I honesty don't know. I've never dove into that aspect. kgg

There are a lot of "after" market parts available for all the Juki machines but for the most part of the same quality or tolerances as that of real Juki parts. I don't even use non Juki bobbins in my machines as the tolerances are all over the place with the cheap aftermarket ones. Yes, you will pay more but they are going to work properly. I would call Juki USA to find Juki dealers near you and explain to them the problem you are having with your tension issue. They may recommend using the Juki LU-1508 NH parts. kgg

Yes, this type of thing can drive you nuts just like the screws which go into the top of the cylinder arm of the Juki's LS-1341 and clones like Techsew 2750 or Kobe Ls-1341. It is a "Juki" thread and right now were costing as high as $4.50 CAD ($3.30 USD) each. It took me forever to track down a Chinese copy at what I would consider a reasonable cost. The cost of odd ball dies would probably be prohibitive for small runs. kgg

Most of the ones that you see for sale on the used market have been used in an industrial setting so probably seen a lot of use which would be reflected in the price. The one you reference appears to be in really good condition with little use. That one if it as good as it shown it's worth the price in my mind. The Juki LS-1341 is the original and are made in Japan with a hefty engineering, manufacturing, advertisement and quality cost attached which is reflected in the new purchase price. Clones are typically out of China or Taiwan. There are a lot of clones, some are good while others not so much. kgg

The price to me seems a bit high but that will depend on your area. In Ontario, Canada a used Juki LS-1341 usually go for about $1500 CAD or approximately $1100 USD complete with servo motor and table. A couple of things to look for: i) is there grooves cut into the thread guides which will indicate a lot of use. ii) paint worn off the body and amount of wear on the foot pedals and frame as well condition of table. iii) check to make sure the built in bobbin winder works properly. iv) the machine should not have any unusual sounds like banging / rattling. vi) the machine should have no slop in the needle bar or other shafts. vii) the machine should sound and feel smooth both when handwheeled over and when running under power. viii) tip the machine and look at the drive belt and all the bearing surfaces for wear / heat discoloration. ix) the original handwheel should be gray in color x) a Juki LS-1341 should have the name " JUKI "in blue above the reverse handle and the permanently attached nameplate / serial number / model number to the left of the stitch length dial. If the machine looks like it was rode hard and put out wet I would pass. A picture of the listing may help to spot other things. kgg

To the best of my knowledge every Singer had their serial numbers molded in the frame. Like shoepatcher has noted the one in the background is a long arm Singer 29K ???. The location of the serial numbers can be found on the flat surface of the body just below where the model badge and company emblem were originally. Once you get those numbers you can go to ISMACS International ( https://ismacs.net/singer_sewing_machine_company/singer_dating_by_serial_number.html ) find the serial number and from that you can find the model model number and the year it was made. You can also do the same for the machine in the foreground since it is also a Singer. kgg

The question I have is what and how thick of material are you planning on sewing? The information I have seen shows that in thick / tough / sticky material a size 21 (130) would be a good choice for V92 thread or in thinner material that needle could be the bottom end V138 thread. If the hole the needle makes isn't large enough the top thread will not form the loop properly and you will get skipped stitches. Also the slightly larger needle will reduce needle deflection in thicker / tougher / sticky materials particularly with zig zag in thicker materials. My experience with doing a zig zag seam, be it with a sailrite clone, is a size 20 (125) is the hole is really a touch too small when I sew above it's rated max of about 3/16" (~4.75mm). This little machine does one thing, edge binding and I regularly sew 7 mm thick material. I did have to make some modifications with a few fancy words of encouragement to get the height clearance under the outer and inner presser feet up to 10mm (touch over 3/8") . kgg

I think we all have had problems in the beginning with one or another machine. If possible a few pictures of your top thread path from the thread spool to the tip of the needle may help in spotting something that may need to be tweaked. kgg

That really is a thin sewing thread and if my calculations are right it is a 3 ply bonded nylon in the range of Tex 23. which would make it a domestic sewing thread size. If they supplied the correct needle for that size of thread the thread is probably breaking rather then fraying as it would only rated to handle a couple of pounds of stress. I would suggest that you get a leather needle 135 x 16 in size 18 and some industrial V69 thread from a place like Wawak.com (https://www.wawak.com/sewing/needles/industrial-machine/schmetz-leather-industrial-machine-needles-135x16-tri-dpx16-d-10pack/#sku=smnl135118 ) and ( https://www.wawak.com/thread/thread-by-use/top-stitch/amann-strongbond-nylon-bonded-thread-tex-70/#sku=atdp1237 ). The needles that came with your machine are for fabric and more then likely of poor / cheapest quality made just to show you it can sew. How thick is the leather you are trying to sew? You also maybe getting needle deflection if the material is to thick. kgg

I looked at your link to the machine and I noticed a couple of things: i) the description states this in it's description " Counting NO: 7MM, sewing system DP*17 16#-18#. " This I interrupt as: 1) can sew a max thickness of 7mm (0.275", just a touch over 1/4") 2) can handle needles from #16 to #18 3) can handle V46 and V69 thread. ii) the description lists it as a " 2972 Leather Sewing Machine " meaning it is a clone of the Singer 29K-72 patcher. iii) the photo's of the top threading are incorrect and you should thread the machine as a Singer 29k-72. The pdf attachment will give you better instruction for your clone machine then you probably got with your machine. kgg 29k71-2.pdf

I would try the simple things first. 1. Replace the needle with a brand name needle, 135 x 16 for leather and 135 x 17 for fabric in the appropriate size for your thread. A good reference chart for needle size to thread size can be found at https://www.tolindsewmach.com/thread-chart.html 2. Make sure the needle is insert all the way in and with the grooves on the side of the needle are to your left. The needle needs to be inserted so the grooves are at the 9 o'clock position. Sometimes you may find in thick material you may have to have the needle twisted ever so slightly with the groove towards either to the 8:30 or the 9:30 o'clock position in thicker / tougher stuff near the max sewing thickness which is about 1/4". Also you will probably have to move up one needle size above the recommended size in thick material so the thread doesn't catch on the side of the hole and interfere with the top thread loop being correctly formed which will cause the hook to miss picking it up. 3. Check to make sure the bobbin cover has the correct size hole aligned with the needle. There should be two hole sizes in the cover plate. 4. Check for any burrs in the needle holes of the bobbin cover plate. What size of thread are you using with what size and type of needle? What is the thickness that you are trying to sew? kgg

Nice to hear. kgg

That is good customer service. So which option did you choose? kgg

I do have one of those cheap Chinese patchers which I fondly call a "Tinkers Delight". If you want a frustration generator go for it. If you would like a 29k clone patcher on a limited budget I think maybe something off Amazon like what is available in Canada new for about $800 cad ($600 usd). Available from for $799 cad: 1. Amazon.ca: https://www.amazon.ca/INTBUYING-Industrial-Machine-Leather-Stitching/dp/B09VXL421L/ref=sr_1_11?crid=208W2UFMBWVPC&keywords=Leather+Sewing+Machine+Sewing+Mending+Machine+Shoe+Repair&qid=1670125739&sprefix=leather+sewing+machine+sewing+mending+machine+shoe+repair%2Caps%2C100&sr=8-11 2. Asc365.com: http://www.asc365.com/SearchProduct.asp?action=search I can't speak to the quality and there probably is no product support but for the price it maybe something to consider. kgg

There two things you need to know. The sewing machines needle system and the needle size capability. The needle system for the Juki 1508 is 135 x16 for Leather and 135 x 17 for fabric and the size of needle is dependent upon the size of thread you are using within it's thread size sewing capability which for this model can handle needles from V46 to V138. The Consew may use the same needle system but without knowing the model number who knows. kgg

The thread is from a excellent manufacturer as well as the needle manufacturer however my suggestions are: i) Change the needle from 135 X 17 which is a fabric needle to a 135 X16 for leather. ii) Change the size of your needle to a minimum #22 (140) for V138 (T135) thread but I would recommend start with a #23 (160) and in thick or tough leather you may have to even move up to #24 (180) needle. iii) When selecting a needle for a particular thread size a good reference chart can be found at ( https://www.tolindsewmach.com/thread-chart.html ) When a needle is to small for the thread the thread loop isn't formed properly as there isn't enough space and so the top thread can get held against the side of the needle hole. That means the thread doesn't form a proper loop for the hook to catch. kgg

I do live in a rural area with my closest neighbour being a kilometer away. Packages for myself and my neighbors get misdirected a lot with Xmass time being the worst. The problem in my area is the drivers are using their stupid phones for directions and not looking at the address marker at the front of the driveways. The worst was I was expecting three pallets loads a few weeks back. The driver pulled into my neighbors drivieway who luckly was at home and stopped the off loading of my delivery. kgg

Glad you got it resolved. kgg

That should catch their attention. kgg