I had to adjust the engine mount. It would "hunt" just as mlevings described on pg 3 of this thread. Once on the ground, I noticed I had down elevator trim for "level" flight, though it didn't level out. I put the engine thrust down about 2 deg from where it was and now rock solid level. Much more trimming to be done ie: she pitches to the belly on knife edge and I need down elevator inverted. Otherwise she seems to be very light, no additional weight added. Lifts off in 15-20'.