ORIGINAL: submikester
Iron, it could be a thrust angle issue...but we'll see if mine exhibits something similar.
Anyway - Since I was out of town most of last week and the weekend weather was lame I've been working on it to get it ready for Saturday morning. All I have left to do is mount the wing servos and balance and she's ready to go. I'll take some pictures tomorrow and post them.
I've installed a HB .61 in mine and had to mount the battery in VERY rear of the fuse to get it to balance at 90mm.
The HB .61 weighs 14.3 oz without muffler(Very Light!!!)
Good luck trying to balance yours without extra weight.
OS 70 Surpass 22 oz
Saito 72 (Engine Only) 16Oz
Magnum 46 16oz
OS 46AX 17.2oz