I fly off of a paved strip, so the LA is going into the avistar. Power, or lack thereof, should not be a problem. Like I said, I don't need gobs of power. Also, the wife already bought the super tiger .40 engine that I plan on putting in the 4*. I think I'll be fine with that too considering that Sig reccomends a .40 sized engine. Would I like a larger engine for the 4*? Maybe, but I think I'll go ahead and use what I have on hand. (unless of course one of you all wants to "donate" a tt .46!) Besides, in the review on the super tiger .40 on this site, the author flew a 4* with this engine and seemed to think it was adequate to fly the plane quite nicely.