Hi there.

First, I would check the lateral balance (put a finger in the middle of the fuse in the back and pull upwards on the prop) and then I would tune the throws down on the elevator. It is snapping, and snapping can be caused not being laterally balanced and a heavy plane also. I flew my Seagull edge .90 with a Saito 150 and it was heavy but it didnt snap when I lateral balanced and tuned the low rate elevator down.

Best of luck

Shane