Originally Posted by
ArchaicArcane
That's really odd, I wonder why? I would have thought the underbits would have been the same... maybe just slightly different timings for the lack of a second needle thread?
What sounds even better is that it sounds like you manual is legible, unlike the photos on the 401 adjuster's manual (the copy floating around the web is a scan of a bad photocopy)
Oh,they're the same bits alright. Just with different adjustments.
Or different timing if you prefer.
The service manual is an original singer one you yup, legible as it gets.
