ernest2
There are some benefits to leaving some spring tension. 1) If your throttle linkage broke or came loose the spring would shut down the enging 2) the spring helps to keep the butterfly in alignment with the bore of the carb.

On Walbro carbs (2 stroke engines) I just take a string and pull the spring back away from and down from the attachment to the lever, allow the spring to 'unwind' 1 revolution and slip it back on the lever. The tension is minimal. I use standard servos on the throttle.