kgg

Some of the rebadged machines actually had the original manufacturers identification in the bottom of the casing. I don't know of any rebadged machines out their today but I haven't looked. Most clones are made in China or Taiwan these days. Even with the Juki machines not all models are made in Japan as I have a Juki DNU-1541S made in Japan and my Juki DU 1181N is made in China. As far as I'm concerned here is a difference in quality. The Juki DNU-1541S, Juki LS-1341 and the Juki TSC-441 are still made for now in Japan. Also some models are made in Vietnam. Seiko's are also is still made in Japan. I do know that all clones are not created equal. The casings maybe a bit rougher some made with Chineseism metal but the problem is some don't use the original style of bobbin mechanisms and the quality of other internal parts can be less then. A couple years back a member was having problems with his 1541 clone bobbin and bobbin case mechanism and when we compared his photo's to my Juki Dnu-1541S they were completely different. Just like the parts in the Sailrite portable walking foot sewing machines are generally less then hence the price difference between the Sailrite at $1500 CAD and the clones at $600 CAD. They have to cut corners somewhere. Dealers bad mouthing other dealers machines is like the pot calling the kettle black. I would ask an independent repair person as to what he generally sees as problem machines. The only advice I can really give about the clones is deal with a dealer brand name or clone that you think can supply the best after market service. kgg

@toxo Looks to be in good shape, price seems in line with what a good used one would cost at about 45 percent that of a new one on this side of the pond. However I would probably checkout some of the clone dealers like Tysew, Typical or Highlead you never know what they may have. kgg

I think if you can afford a new Juki LS-1341 you will be pleased however if you need the smaller gauge nose then you would need to go to the LS-1342 which would also give you the additional vertical stroke adjustment for going over thick seams. Here is a link to the Juki LS- 1340 series so you can compare the models in that series. ( https://www.juki.co.jp/industrial_e/admin/pdata/filedata/332/ls1340.pdf ) Then there are the clones which are less costly. kgg

This a Seiko design. They were market in North America by Consew as the 206RB and the Singer 531 same machine just a different badges. kgg

Juki machines overall are excellent often copied but the quality like everything else comes at a price. The price difference can be substantial, an example would be a Juki TSC-441 will set you back about 10 K CAD versus a clone costing about $4000 CAD. On the used market the Juki's are easier to sell and will command a higher price then a similar clone in similar condition. Parts and accessories generally are easier to find at reasonable prices. kgg

This what I think I know of your Singer 531B-8BL probably built around mid 1990's were rebadged Seiko's STH 8BL and sold by Consew as 206 RB, Singer 531-8bl and possibly Chikon CK-8BL( http://www.chikon.com.tw/ck-8bl.htm ). The front head assembly (needle area) look awfully close to that of a Juki LU-563 but different reverse / forward stitching mechanisms to my mind. There is a couple of manuals which may help. kgg Consew_206RB_Operating_Instructions.pdf SINGER_5318BL.pdf

You are in the used sewing machine market as even a one arm bandit like a Tippmann Boss will probably run $1500 CAD or so with rate of exchange and shipping. The next questions: i) How thick of leather are you planning on sewing including seams? ii) What size of tread are you planning on using, size wise? I think you will be disappointed investing in a Sailrite LSZ-1 clone. Have you checked with places that sell leather, do industrial sewing machine repairs? kgg

Be aware that the Omega portable walking foot is nowhere near the quality of an industrial sewing and the internal parts are not going to be that of the Sailrite portable walking foot machines. The portable walking foot machines were designed to sew sail cloth and are more of a domestic sewing machine with a walking foot rather then a industrial sewing machine. You will find as the thickness of the item being sewn increases the stitch length will decrease, the bobbin is that of a class 15 domestic sewing machine bobbin, presser feet are very aggressive. feed dog is very aggressive, only presser feet and feed dogs made for the portable sewing machines will fit and it can only handle V92 thread, which is one size up from domestic V69 thread. If this going to be your only machine I would strongly suggest you look at other options if you want to sew leather. What is your budget as there maybe other options like a one armed bandit? kgg

I wouldn't bother with purchasing this machine particularly since it does not have reverse and it has a clutch motor. Learning to use a clutch motor has for most a steep learning curve. Upgrading the motor to a servo motor will set you back another $150 to $200. I would suggest looking for something like a Juki LU-563 or a Consew 206rb. What part of Canada are you in? Someone maybe able to suggest a dealer near your location. kgg

I re-sized your photo to get a little better look at the speed reducer. It appears from the photo that the wick goes to the bearing for the lever that actuates the motor. I would carefully remove the speed reducer / lever mechanism from the table. That way you could better see how and what the wick actually is suppose to prove oil to. You said " Both old leather belts are slipping, I assume because they seem to be saturated with oil. " Once you get the belts off can should be able to see the path the wick is taking from the oil pan and how / why the belts are becoming oil soaked. You are going to have to at least try and clean the oil off the belts, remove any oil from the pulleys where the belts set or the belts will continue to slip. If the wick is use to oil the bearing for the lever that actuates the motor you could probably just stub it off and remember to put a few drops of oil on it every once in awhile. If you decide to replace the full wick from the oil pan to it I would suggest threading a new wick through a tube (metal or plastic ) so that the oil doesn't natural drip down on the pulley and belts. As for: i) the wicks think of 100 percent cotton wicks used for oil lanterns which can be had at hardware stores or 100 cotton cording used in upholstery edges on seats which can be had fabric stores. ii) cleaning the bearing out by flushing with thin oil and compressed air or even a tin of 10w24. A couple of additional photo's would help. kgg

Yes this is often done. I'm assuming you are in the US so I would check with Toledo Sewing Machines ( https://www.tolindsewmach.com/ ) for a speed reducer and a servo motor pulley. kgg

From what I can gather and I don't know much about linen thread the #16 that you are using in the Juki 341 is a 3 cord or 4 cord which has a thickness of 0.56 mm or 0.65 mm thread equal to about: i) #16, 3 cord just a touch over V207 which means it should use probably a#25 needle ii) #16, 4 cord just a touch under V346 which means it should use probably a#26 needle. So since you are using it in the Juki 341, i) I figure you are using #16, 3 cord as that machine isn't rated to handle a #26 needle or V346 thread. ii) The #22 needle is good for V92 thread or about a #30 linen thread. iii) The #25 needle you are using in the Cobra is good for V277. If you can read the information off the barbours thread spool to get a size or if you could measure the diameter of the thread someone more knowledgeable could suggest a proper size needle that may work. The Class 441 machines, Juki or clones are only rated for thread up to V415 or thread with a diameter of about 0.28" or .72 mm. kgg

You may want to check with Leather Machine Co. for how you need to set the machine up. Also attach a couple of photo's of how you have threaded the machine as they may recommend a different method of threading. The Cobra clones are threaded differently then the Juki TSC-441, the Cowboy or the Techsew. Here is a topic with photo's of how the top thread is threaded differently on these machines. You could try and thread the machine like a Juki TSC-441 and see if that works. Different thread path, different tensions, different number of top thread tension points. Also what size of needle are you using in the Juki 341 with what size of thread and what are size thread are you using in Cobra with what size needle? kgg

The two leather belts indicates to me that the machine has a speed reducer pulley setup and the wick going into the oil cup is to lub the speed reducer pulley bearing. Any light oil should be work. When you replace the pulley belts if possible replace the wick and flush the bearing out. kgg

Yes you are correct just no letter before the serial number. I misread the information. kgg

Nicely done. Neat and tidy. kgg

I almost bought a one armed bandit and came to the same conclusion before getting a Class 441. Now it just comes down to which machine best meets your budget, needs and who you feel will give you the best after sales service. As far as accessories / attachments that is going to depend on what your needs are. When it comes to the needle positioning some people like it and others not so much. My machine did come with the needle positioning along with a 9 coil brushless motor. I never installed the needle positioning and the jury is still out as whether I keep the brushless motor on the machine. kgg

I forgot to add that there are presently three one armed bandits available, Tippmann Boss, Cowboy Outlaw, Weaver Cub. kgg

The site for dating the Singers I would use the " International Sewing Machine Collectors' Society ". Dating your Singer by serial number ( G4763530 ) indicates it was made in Elizabethport between 1916 -1918 and with your machines having a low number for that series probably built in 1916. ( https://ismacs.net/singer_sewing_machine_company/singer_dating_by_serial_number.html ). The way I read the information is that 29K machines built prior to 1900 had No serial numbers. As far as getting the thread through if you have access to a length of #20 AWG copper wire, guitar string I think is smaller at #22 AW or #13 piano wire. Those should go through. kgg

Simple answer is Yes. My simple way of determining the class of machine. If a machine uses the 794 X SIZE of system needles then it is a Class 441 where SIZE is the size of needle that is determined by the size of thread being used. In the class 441 you have the one armed bandits and the machines with 9", 16", 25", 37.5" cylinder arms. I class machines basically on what the equivalent Juki or Singer series of machines it best's represents like 29K / 1141 / 1541 / 341 / 441. For someone new to machines trying to figure out which clones have similar capabilities can be a chore. kgg

If your thread range is V138 to V346 then you are into a class 441 machine to handle the V346 thread. If you are planning on selling / repairing traps or straps in general for other people be very careful, get trained, certified and insured. It isn't just about that you can do the work or what machine can do the job it's the liability should things go south. kgg

I think you got a bum motor. I think the best solution before making changes to the hand-wheel would be to replace the servo and get that sorted out first. I would suggest looking at either a brushed servo motor something like the CSM550-1 or an electronic controlled servo motor with at least 9 coils, 12 coils would be preferred like the Sailrite workhorse or the Reliable SewQuiet 6000SM both are 12-Coil servo motors. kgg

All the Juki's and the clones like Cowboy CB-341, Cobra Class 26, Techsew 2750, KOBE LS-1341 to name a few in the 341 / 1341 class cylinder arm machines all have the hand-wheel orientated so the belt is closest to end of the machine and main bearing. When you move up to the Juki TSC-441 and the clones like Cowboy 4500, Cobra Class 4, Techsew 5100, KOBE TSC-441 to name a few they have their hand-wheels orientated with the belt on the outside. A lot of the Singers like the 111W 155 had their hand-wheel orientated with the belt on the outside while the Singer 212 the hand-wheel is orientated with the belt on the inside. Pfaff also had a mix the 1245 had the belt on the inside while the 145 and 545 had it on the outside. I guess it comes down to how each class of machine is designed and how the "all alluring" belt cover is supposed to be installed. I am surprised as I don't know of any manufacturer / dealer that ships the machine with the hand-wheel installed on the machine over on this side of the pond. You should have your brother bring leather needles along in the size for the thread you are planning on using. Needles for the Juki and clone 341 / 1341 use 135 X 16 X SIZE for leather and 135 X 17 X SIZE for fabric. Here is a good link for needle size vs thread size. https://www.tolindsewmach.com/thread-chart.html kgg

The jerk is probably from the minimum startup speed of the motor you are using. Yes, increasing the size of the hand-wheel will help with slowing the machine and increase torque. However it will not eliminate the startup jerk. I think you would be better installing a proper speed reducer pulley and leaving the existing hand-wheel. You will get better speed reduction, increased torque and it will help to reduce / smooth out the startup jerk. kgg

What size of thread with what size of needle are you using? Also a few photo's of how you have your machine threaded maybe of some help. kgg