Intake Manifold rubber cap

[GreetSlide808]

What is the purpose of the silver tube and rubber cap on top of the intake manifold? I removed my tank for the first time to check for loose connections and fittings and noticed the rubber cap was not on very securely.

 

[hulkss]

A "purge tube" is connected where the cap is on California bikes.

 

[GreetSlide808]

Thanks Hulkss