Did you shorten the tail boom at all when you did the buildup? That thing is WAAAAY longer than the stock tailboom. It's hard enough getting the CG forward as it is..
Skiddz
I left the tail boom alone. It was tough to balance with the second tail motor on there but that didn't last long seeing how I burned them both up in under a minute. Now I have 1 tail motor and the battery very forward. CG is now dead level. I didn't like how it flew when it was a little nose heavy.
Q: Are you using a LiPo or stock battery?