Breather/vacuum pipe

On investigating a newly acquired 1995 Thunderbird I have found a pipe running from a connection between carbs 1 and 2 to the breather connection on the rear of the fuel tank. According to my Haynes manual the tank breather should go to some sort of valve to prevent leakage if the bike inverts. No sign of this. I think the carb connection is a tee connection between the top of the body and is either a vacuum or some sort of breather, Haynes is not clear where this should go. Help would be appreciated.

 

Thank you. Unfortunately this is for an evaporator system which, thank god, I dont have. Think I am going to find another thunderbird and steal a look.

 

The pipe between 1 and 2 carbs is a vent and should be open and it's poked down behind the air filter. The fitting on the rear bottom of the tank is also a vent and must also be kept clear or you'll get all sorts of running problems. A link in the rubber pipe is a prime candidate for this.