If you changed the pilot to a 25 thats is your problem im running a 40 pilot right now 15 degree weather. Only time I run a 25 is on my ported setup on stock carb that is in the dead of summer. If you dont quit messing with all your jetting circuits your going to fry that motor  in the cold  where you live one circuits at a time get it idling to 1/4 throttle adjust the needle to 1/2 . Then recheck to see if you idle is fine. Then go on from their 3/4 to wot throttle one at a time you need to read in tech section Carls  write up about jetting l. I will bumb so you can read it. It will help if you choice to  use it.