DON'T cut lumps out of your machine. There will be a sequence you use to remove the parts you need to access to the gears more easily. The Youtuber you referred to sounds like they have zero knowledge when it comes to these older style machines.
'Note' Some of the gear mount nuts are on a "Reverse" thread meaning you turn them the 'wrong' way to get them off.
My limited knowledge is more on the much older hand crank and treadle machines.
Try the Youtube link below for a channel called 'Andy Tube'. He has a good reputation for correct repair methods. The link is for a 758 but they're both Touch and Sew machines.
You could also try the Facebook group 'Vintage Singer Sewing Machines' as they have loads of knowledge about loads of different machines.
https://www.youtube.com/watch?v=zxd5hKjGBlE
If the one and only problem is that the wheel is very stiff, doesn't that suggest some fluff, or what, is blocking the wheel?
Are there any other symptoms?
Incorrect threading.
Bad tension settings top and bobbin.
Bad quality thread. Cotton can go rotten as it is organic.
Other ideas in textual form and videos.
Look around the screen and see if there is a contrast adjustment knob. It might be on the side of the machine or on the top of the machine or under the screen. It is possible the the contrast of the machines screen is off. If that is not the issue it might be a loose cable inside the machine or it could be something more serious.
Question edited for clarity and spelling 'treading' to threading.
Question moved from Cars and Trucks category to Sewing Machines.
It is a professional machine and in a normal daily working environment needs servicing every 6 months. When was it last done?
https://www.google.com/search?q=kansai+w8103d+threading+instructions
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No they have to be on the outside and visible by law. It should be at the back where the power goes in. Voltage, Power Consumption, Maker, Model Number and Serial Number,
See Jiku Website. You can download the required manual by giving type of machine, model number etc.
Juki-Manuals (jukilanka.com)
There are more than 400 manuals on this site. You can find your required manual.
Juki manuals
