Northmount

Service manual should have instructions on setting the check spring position.

I see a parts list at https://www.supsew.com/search-results/?wpfb_s=46k46 But no instruction manual. Further above in this thread, @Constabulary said he has one of these machines. Maybe he has more information that can help you.

The pin must be slightly tapered. Put some fingernail polish on it, tap it into place - gently. Clean any oil off the pin and out of the hole first before applying fingernail polish (or other retaining compound such as Loctite - various formulations like Loctite 290 thread locker). EDIT: Do you have a manual for your machine? Lots of manuals online for 20U33. Just looked at my 20U33. It doesn't have a pin. My machine is blue, from about 1975 if I remember right.

@KeriHat The check spring is adjusted by rotating the assembly to the desired position before you tighten the retaining screw. Do a search for setting the check spring.

@Tophee Moved to Tooling, Stamping & Carving Leather > Dyes, Antiques, Stains, Glues, Waxes, Finishes and Conditioners

@Pink1977 moved your post to leather sewing machines since this is turning into a sewing machine discussion.

Moved your post to > Marketplace > Items For Sale > Machinery -- Sewing and Stitching > Used

Split your post off an unrelated thread. You'll get better response from properly titled and placed post than you will from contaminating another unrelated thread.

You seem to add spam links to vendor sites every so often. Please provide info, not spam. Moved this thread to 3D Printers and Lasers

This forum includes both hand and machine sewing. There is a separate forum for sewing machines where machine types, troubles, how to, problem solving are discussed.

Moved your post to Gun Holsters, Rifle Slings and Knife Sheathes.

Moved to leather sewing machines. I think you may have better luck here.

Moved to wanted

Moved to sewing leather

Moved your post to leather sewing machines.