When my DH was doing maintenance on the 2009 GC250, he noticed that the vent hose from the rear gear housing
to the Air Box was cracked and not connected to the air box. He is in the process of replacing the hose.
We just wanted to alert other owners to this problem...
Not sure what effect it would have except the air:fuel ratio may be a bit higher.
The Kymco hose isn't expensive but perhaps regular auto parts hose will work.
Scoot safely.