I bought an 07 400ex (upgraded from my 01 300ex) and I'm getting ready to tear into my carb and I noticed this hose sticking out and not going anywhere. Is it just a vent? My first thought was a vacuum line for the petcock, but then I saw that it is not a vacuum operated petcock. I see on it's located in a place unusual for vacuum so I started it to see if it was. As expected, it's not vacuum. What does it go to? If it is just a vent, where does it lay? Thanks in advance!

 

It look's like a vent hose/bowl/overflow the way it's routed up high , i could be wrong but that's what it look's like to me ; look's like 2 hose's hooked into the one you're holding!
Look for another hose hooked to the bottom of the carb bowl , if there isn't one on the bottom ; then it has to be for the carb vent/overflow .

Good luck to you and welcome to the forum !

williebee.....

 

if you lift up that rubber pad i think it has a hole in the frame tube right there it gos down in.

 

it goes right on top through the black rubber peice with the other hose