RE: Carburator spring
I use to disconnect the springs or move the hook to a hole with less tension, but for the last several engines, I just leave it in place. If you measure the current drawn by the throttle servo with the spring in place, the draw is minimal. It takes very little servo power to overcome the spring. There is some safety in leaving the spring in place. If the throttle linkage should fail for any reason, the throttle would spring closed.