Here is a pic of my ATC70 carb. A hose goes on that spot for a vent.
tmas

 

does the other end of your hose attach to anything? or is the breather hose just to discourage spiders and dirt from finding a tight home?

 

Here's a pic of the hose off. Yours looks to be broken off.. maybe?
tmas

 

You can't see in my photos, but i do have the 1/2" nipple on the carb body for the hose to mount (thanks tmas). But when the hose clamps to the carb right there, where does the other opposite end of said hose go to on a normal/working setup?

 

Most likely the vent hose just goes down below the motor or into the frame maybe. It just allows air to pass...in or out. If you are getting fuel leaking from the vent, your fuel level, in the carb, must be reaching that height!.. Stuck float, wrong float height setting, hole in float, bad float valve/seat, etc. It would seem almost impossible that the fuel level could go that high...so, maybe I'm missing something.

 

Most likely the vent hose just goes down below the motor or into the frame maybe.

That's correct...
tmas

 

nice. thanks. Ill toss a breather hose on it for good luck.


@kirrbby - it only leaks when off bike, upside down in hand.

 

Doh! Guess I didn't read past the pic in your #1 post.

One thing I've learned about our carbs, every mysterious hole, leads to another. With a proper carb cleaning, I shoot carb cleaner into every hole I find, to make sure it comes out of another...at least one other, sometimes two.
If you shot C-cleaner into that hole, it'll come out of a tiny hole in the "ceiling" of the float chamber. If not, it's plugged.
I do that with each hole or port on the carb to be sure all is clear before I put the carb back together. It also helps to give me a clue of how my carb works.