Screw instead of a vent to the cylinder

[Wilmer]

Hello. I have a GasGas EC 125 05. And I saw that on the left side of the cylinder there is a little screw. But when I looked in the partlist of the bike I can see that there is going to be some sort of a vent with a hose on. In the partlist the name of the thing was DESVAP. I wonder what that vent do and if I am going to replace the little screw with a knew original vent with a hose on? Will there be any difference? Will the bike go better or is it just better for the engine if the vent is there. Here is a few pictures of my bike and someone else's bike with the vent.

My bike

Attachment 7392

Attachment 7393

A bike with the vent

Attachment 7394

[Gasser Nate]

It is probably just the power valve chamber drain, if you run the fitting and a hose you won't have to drain the spooge. It'll go the same.

[Wilmer]

Okey, thank you for your reply. Then the best thing is to replace it with a vent and a hose instead, regardless it makes any differents or not.