How long is too long for a snake to go without eating?

I have had the same problem with my king snake. As long as the snake is not too skinny then it is ok for the snake not to be eating, it may be just fasting. One thing to try is small lizards (you can find them live at bait shops) or buy some baby guppies and put it in there water bowl. I even talked to a reptile vet who said to take a pinkie and make a small insestion near the head or put other lizard or snake sent on the pinkie ( since kingsnakes eat other snakes). another reason it might not be eating is the temputure in the cage, if it is to low it may not eat. Also make sure you have two proper hidding places in the cage and are not handling it to much in this case you are probaly stressing it out. Hope I helped!! :)