Even with a 27-10 it will be fine for break-in I think, just don't keep it full power. I run mine slow and easy for the first few gallons.

Nice slow flying, its a good way to get a good feel for the plane anyway. Mine can be slowed way down, even at 25lbs, and its fun just doing slowwww inverted, upright, loops, rolls, spins, and a little full tilt stuff just to see what it can do. The 3W is very robust, mine has been outstanding, no overheating at all.