Help guys, it's you old aggravating friend with more questions about the Rotax engine. I have decided that will be the engine that I was going to put into a Kitfox STI but that has changed as well. I am going to go with the Rotax 912 ULS (100hp), I just need to know the difference between the 2 & 3? I know that the 2 is 6 lbs lighter than the 3 but all the other dimensions look the same. That being said and it may not even be relevant the new kit will be a Just Aircraft Highlander with the Rotax ULS. Also going to go with the Kiev #293 prop as I've read that setup works pretty great together. It's also about 700$ cheaper than the Whirlwind prop I was going to go with. Sorry for rambling on folks and thank you all for your time and information.