This is how the spring is supposed to be installed. Also, Your spring is not the right spring so it may not have the correct tension. You may also need an additional spring as I mentioned, on the vertical throttle rod. Fenton use to make linkage for their intakes that had the tab already welded, to assist with the upper linkage rod.
Others have mentioned a spring for each carb. That works but if you are using the straight unadjustable rod and tab style linkage (like the offy intakes use) the carbs have to be set exactly the same in terms of throttle arm opening/position or they may not close, especially if one carb is open a bit more then the other. You need some independent adjustment for each carb and a tiny bit of slop in the linkage. Also, it’s easier to synchronize the carbs if they can be independently adjusted.
