I've not changed mine, so just guessing.
On other's I have changed, after letting it run just enough for the bars to start showing, I shut it off and checked the level again. Always had to add some.
Same with car. Repeat the process UNLESS you didn't add some, then it should be good.
Again, I haven't done this with mine or any Kymco. This is my first Kymco. But if I'm wrong, maybe this will get someone to chime in.