dmanshep, The outside temp does have some do with how it runs. It is about 45 Degrees here in Tucson and I am going to wait to break in my wifes new engine when it gets alitle bit warmer, but you CAN break it in, in cold temps but you should break it in close to the temps you plan to run it in.

Also the cold air is more dense so you will have to tune it richer to compensate for the dense air. Which in turn COULD Create more power.

Running it in cold should not hurt it, tho

Good luck, and have fun!!