I am not understanding why my new build wants to turn over when throttle up!!!

I have solved the esc throttle calibration issue. I have balanced 2 of the 4 props with small pieces of aluminum duct tape and they show very even balance.

My build is currently as follows:

AreoSky 98oKV motors

Hobby eagle X6L Fight controller (not totally happy, have ordered KK2.1.5 Mini LCD Flight Control Board 6050MPU 644PA KK2 KK2.1 36x36mm USA Seller

Orange R620 Receiver and or AR8000 Receiver

Spektrum DX6i Transmitter.

Power distribution is of my own DIY design

F450 Quadcopter Kit Frame / Heighten Broaden Landing Gear Skids for RC F450 L4W8 frame

2200 lipo battery

SimonK 30A escs

Is there anyone out there who can give me some input as to how to resolve the issue?