Thanks a lot for the tips..... yes, you are right, battery more at the front and servo would have eliminated some weight, the thing is that I had limited time to assembly. I never thought the plane would be so much tail heavy because the manual recommends 46 engine. I almost finished building before checking the CG and this post where everybody said it was extremely tail heavy.... too late to take out servo, fuel tanks, etc. So, I went for the easy: put weight and bigger battery (battery is under the fuel tank).....

However, you are right, I'll have some flights more with it, and one day I have more time, I'll do what you suggest, for the moment, I just need it to roll and loop decently for a while...

thanks for your input....