In theory, I suppose you could modify the YBX. But look at some other things first. Take one of your SSX engines and try it on her kart. It could be the kart or its setup or that engine needs a rebuild. You could also try just putting one of your SSX cans on her motor. And before you start drilling on the YBX, see if anyone local has a used SSX they’re willing to sell you. I’ve got at least one extra I could part with and I’m guessing there are some near you as well.
LAD Specialties customer / tony kart / rotax / kt100