2001 90hp Evinrude Carb Needle Spring

[mav6759]

I notice today all 3 of my carbs have a spring on the crab needle adjustment screw. Can someone tell me what that spring is for, and what does it do.

 

[racerone]

?----3 or 4 carburetors ??------The spring puts tension on the screw so that it is less likely to move on it's own.