I saw some posts on the 4-cylinder making the XL too heavy, but seeing how long a wait for a 2- cylinder engine to be built by Casler had me wondering. Assuming someone didn't mind going the LSA way and looking at the max weight of 575#'s, if you added a 4-cylinder, the gas tank (8 gal) was positioned behind the pilot, and the pilot weighed 210 or under, wouldn't that keep the weight or CG from going over? I'm just not seeing the difference if the pilot is of average size.
Thanks,