Mike, If you'd like a free .pdf Owner's Handbook, a Parts List, and an Engine Adjusting & Disassembly Guide for your 1973 S 3800, just send me an e-mail at: briansolex@live.com
Also, check out my latest Solex 3800 USA website:
https://solex3800usa.blogspot.com/
And my BrianSolex Youtube channel:
https://www.youtube.com/c/BrianSolex
Playlist of BrianSolex "How to" videos:
https://www.youtube.com/playlist?list=PLgAp0hMqCDUtRoIkafKKmndsF5sLa8LVQ