So, a few days ago, I reversed the work I did on the choke linkage and then adjusted it using the throttle cable clamp as you guys suggested. I was actually able to close the choke tighter that way, and it was easier to do than bending the linkage (I bet you already knew that ). It was still fairly warm that day (>40 deg.), and the tractor fired right up. Today it's closer to 30 deg., and I needed the tractor to drag some firewood up to the house. She fired right up and ran great. I'm going to call this one solved. Thanks a lot for your help!