I hate the thought of adding weight to such a light little model. If it flies like it's far too nose-heavy, I'll swap out the Super Tigre G40 for a G34. It has a little less horsepower, but about four ounces less weight so I think things kind of balance out. My first choice of engine for the little Ultimate was a G34 ringed ABC Heli engine, which isn't made any longer. I have two, but they are going in a Hobbico Twinstar ARF. I have a regular "aero" ringed, steel cylinder version of the G34 as well (and a little J'Tec Pitts muffler for it). It may end up in the nose of the Ultimate.

Good flying,
desmobob