None of my Cubs have spring spiral spaces without tension on the spring. Someone in the past may have sprung your spring, since it's a bugger to install.
Here's info from TM Tractor's website:
The pictures can be deceptive since they are a composite of a lot of pictures, taken over a lot of years, of a lot of Cubs, in a lot of places. I did the repair with the governor housing installed, out in the snow during sub-freezing weather back in February.