Welcome Kymco Owners!
google search the sellers.
There's important differences in o-rings when installing in gas engines. This kind of search might not yield useful information - go direct to experts such as these folks: https://www.fst.com/news/2015-fst-new-o-ring-configuratorFreudenberg Sealing Technologies dealers in almost every city in the world.
I could not find anyone selling just the o-ring
No need to despair, Freudenberg dealers (they're everywhere all over the world) will sell you one o-ring if that's all you need.
I checked.Indiana and Canada are to far to go for a $.35 o ring.