I have a Baja 250. I was replacing the cooling fan and when I had it back together, I see this mystery hose laying around and don't know where it came from since I didn't disconnect any hoses so I'm hoping someone can tell me where it goes. It's some sort of air or vacuum line and has a clamp as if it was somewhere at one point. Here's some pics attached.

 

i couldn't imagine that being a crankcase vent. especially going to a canister. what's that canister apparatus? do you know? is it connected to anything else? looks like the hose is small enough to latch on to the carb somewhere. i'm sorry, i really don't know, just trying to help. surely there's a nipple within range of that hose!

 

I have no idea what the -canister is. But it has 3 hoses coming off it. One goes to the other side of the engine, forward and under the carb. Another hose goes to this side of the engine where the mystery hose is and plugs into the case where the oil fill plug is. And this 3rd hose, I have no idea. I can't find any open nipples anywhere.
Since it just appeared after my fan work, I'm wondering if it was just stuffed somewhere ever since before I got it and just never noticed it. It still runs fine, at least at idle. I just ran it in the garage to test the fan operation and haven't actually driven it yet. But that hose is either sucking or blowing air, can't really tell cause it seems to be cycling.
I'm wondering if that canister is one of those charcoal canisters for emissions like cars have. It sort of looks like one, only a smaller version.

 

i honestly don't know on this one. first i've heard of an emissions canister on a quad. wow, i'll keep looking though. so the crankcase vent goes to the canister? and the overflow of the carb goes there also or is the carb hose on the vacuum side? is the hose long enough to reach the gearbox for its vent?

 

No, I don't think so. Maybe I'll take some more pics this weekend and see what I can or can't figure out.