Cam box vent pipe

[Popstar]

After assembly of my carbs from a box of bits I've discovered two vent pipes , the longer one comes out of the vent on the cam box which is very long and would fit on the offset tube appature on the air box, the other pipe has a larger diameter pipe and is sleeved down to a smaller diameter pipe but doesn't appear to have anywhere to live. The bikes is a 71 500k1

[Bryanj]

71 500 cam vent goes down behind crankcase and open to air, there is also a tube from airbox that does same. Only the 550 recirculate

[Popstar]

Ok thanks, I've not come across this before(the one from the air box) I will of course connect it now I know, won't his pipe breath in unfiltered air when you consider it's position?

[Seabeowner]

The original pipe from the airbox terminated in a slit so was basically sealed. You were supposed to squeeze the slit to open it to drain any fluids there.

[Popstar]

That makes sense.

[Sesman]

Pipe is Plugged with a slit so seals on negative pressure.