Crankase breather hose or something else ?

[gvp90000]

I have a 2stroke yamaha model 30DEO.
6J8K - L - 1003853
6J8-D0 Model 2004

What is the purpose of the hose in the picture below (part number included) and is the term "Crankcase breather hose" the correct one ?

Thank you.

[boscoe99]

I don't see it listed as a crankcase breather hose. Yamaha lists it as just a hose.

When I think of a crank case breather hose I think of a four stroke.

My guess is that it is an oil recirculation hose.

[99yam40]

or crankcase recirculation .
I believe it recirculates liquid oil/fuel that settles out at the bottom of each crankcase section that does not make it into the combustion chamber to burn it
should have a check valve involved