jetjockyf, do you have the Taurus 3.2 on your pitts?. If so, how does it fly and Bill O. does not recommend removing the spring. Personally I don't think it is necessary. According to some..the spring keeps the shaft from wearing out the carb body. I'm not sure I agree with that but some people believe it to be true. Taking the spring off won't change your idle, your throttle linkage is responsible for that. Make sure it is 100% positive in the open and closed position.
I have 10 years in the Chain saw industry in my past if that means anything.. Regards BobH.