I got my 4wheeler second hand partially disassembled. I have no clue how the vacuum and breather lines are supposed to go. Currently none of the lines or breathers are hooked up and I cannot find a diagram anywhere online. I have a Bear Tracker but I would think any 250 would be similar.

 

Shouldn't be any vacuum lines on your 250. Should be a vent hose for the carb....but could be two of them, a carb bowl drain hose, a fuel line of course, and a larger black hose that connects to your air box..... the crankcase vent. If you get confused, post a pic of your carb and Iwill try to help you.