Just finished installing a new O.S. .25LA on mine. Originally flew with a magnum .15XL and it was enough to hover but just slightly under full throttle with very slow pull out. So, picked up a new LA yesterday and installed it tonight. The weather around here really sux but if and when it is decent, i can't wait to get out and try the new engine. Anyone else have much experience with the .25LA combo yet. Only weighs 2oz more than the .15.