Bump.
I’m in the same boat. Just bought some used Seraphs that were sparingly run in juniors. You can search the forums, like “seraph setup,” and see what people posted years ago. A lot of it ranges around:
46.5-48% font
57-60% left
60-64% cross
But I’d like to know if this is accurate. Any help would be greatly appreciated. One kart running Medium and heavy, other is a beginner junior.