Carb question Subaru engine

Mini Bike & Go-Kart Parts

I have a Subaru ex21 with efi.
I was thinking of replacing the fuel injection with a carb. My logic for this is I would expect the efi would become problematic after a while and a carb is easily fixable. The problem is, I have no idea of what jets they use and I assume adding an less restrictive air filter would call for a rejet. I’ll attach a picture of the carb I’m considering. if anyone recognizes it, give me the lowdown please.