I can pull a motor off of a Singer 201 in about five minutes now. That's because I have done it so many times. I know a fair bit about older Kenmores, too. I don't know squat about newer machines, but the last two Taiwanese made machines I was able to at least take apart to get to their innards.
But the Viking that Andrea and I worked on is totally different from any machine I have ever worked on. Except that, like almost all of the others, its major problem was being dirty and gunked up.
Or so we thought.