Sandy,
I saw the photos in the link provided but I thought that spring set up on those Holley carbs may have been for a car set up. When you lift your foot off the accelerator peddle is required to spring back. You have to manually bring back the throttle on a boat. That's why, I thought there may be some differences between a car and a boat. I have looked specifically for a Crusader 350 set up online, I haven't seen any exploded diagrams that show an axial spring. I have had this boat for 20 years and never saw an axial spring connected to the throttle linkage. That's not to say there shouldn't be one. I would just like to have it right.
Thanks,
Johnnie