ok, so i have run the gammut of research on all of the engines and have decided that the 912uls with an efi package is probably the way to go. without going into all the ins and outs with compare/contrast, let's just say that reliability and proven performance has led me to this point. quite simply, the 912 can take a substantial beating in many types of airframes. for the kitfox, i believe it is head and shoulders above the likes of viking/honda (NOT an aircraft engine!) for STOL aircraft. sure, other engines will work a treat, such as the O-200 and 235, but rotax has the proven history / performance for higher revving engines to do what STOLs are supposed to do, namely, get off the ground quickly. i just want to find a good used 200 to 300 hour 912uls to add an efi package to.