I spend most of the day cleaning a very dirty Adler 67 GK 373. Lots of lint and old dried oil, but it come out looking nice and I didn't find any worn parts.
After putting everything back together there is a timing issue only on the beginning of back stitching. When the hook rotates contra clockwise the hook hits the feed dog. Forward stitching is fine.
I've watched the video Uwe put on YouTube, and checked the hook timing that looks fine.
Any ideas how to fix this? I asume this is not normal
Thanks
here are some photos of the hook hits the feed dog (before and after)