My last comment. Unless your buying your fuel from the refinery you really don’t have and idea how old it is.
Your fuel passes through your crank case. So unless your dissasembling the engine and drying it out you’ve got ethanol sitting inside.
It may not matter or you may tear that engine down one day and wish you had stayed away from ethanol. As you said everything in karting is expensive and time consuming which for me is a reason to stay away from it.