Mobil-1, 20w-50. Started at about 10k miles (bought the scoot new), have 165k miles now. The other Connie in the shed had ~ 18k miles when I started using Mobil-1 as above, now has 80k+ I change oil/filter at the same time as tires, about every 9k miles. Have gone longer.
I generally like the oil that comes in plastic containers with a screw top. And generally pour the oil into the hole in the engine case. And usually, but not always, so you can see it in the glass thingy in the engine case.
Oil is good, make sure you have some.
Rick