jetjockyf18, Is it possible that the butterfly is hanging up in the body of the carb and when you move it to the side that it becomes unstuck? I can't see why the spring by itself is causing the problem? BTW how does the Pitts land with that engine? I am looking the Eagle for this Taurus Engine. It's supposed to be for my Yellow P-47 Jug but that project is on hold for the moment. I am finishing a Duncan Hutson SE5a for the Scale Masters next year lol!.. BobH.