Go to the auto parts store and get 5 or 6 feet of 1/4 inch fuel line and run the vent tube all the way up the frame and down the rear splash guard so it vents out the back. Having it run uphill on the frame will keep the oil from spewing out but if a little does come out it will drop on the ground behind you. It won't amount to much. You can drill two small holes about 3/4 of an inch apart in the rear splash guard and run a zip tie through them and around the tube to hold the tube in place. I did my blue scooter like that.
Ride your scooter to my shop with the fuel line and I'll show you how to do it for a 6 pack of Coronas.

We can plug off that smog crap while were at it. Tomorrow I have to got to Los Alamitos in the morning but I'll be back by 1 or 2 PM.