What happens if you don't winterize. Say you leave your ski for about 2 months. What is the longest you can leave it without winterizing?

Leaving your ski sit (not touching it at all) for any length of time will lead to problems. The gas goes bad, battery dies, carbs or injectors gum up, etc...

It's a good rule of thumb to prep your ski for storage if you're not going to use it for a month or more. If you live where the temperature drops below freezing you must winterize your ski. Any water left in the cooling system will freeze possibly damaging parts beyond repair. You won't even know it until next season when you go for that first ride. Which you will then be stranded and mad.