Hi, all. I'm fairly new to quads and have taken on the project of resurrecting a broken Eachine Assassin 180 that I bought. In doing this, I have replaced the motors and ESCs as well as added the wiring and brackets to support a non-proprietary battery. If all goes well, I'm planning on finishing up an action camera mount on top. 

Once I got everything wired up and secured, I tested inside to make sure everything spun as it should. I immediately found that it shuttered very badly and that the roll and pitch seemed to not be very stable. I then decided that maybe my issue was some sort of ground effect and I should go outside. I did this to find that I couldn't get more than 2 feet off the ground and it still shuttered and floated around. I am not particularly good at acro in LOS, but I this is moving worse than I would expect. Additionally, I found that the motors with black propellers get pretty warm after a short time while the other two are cold. I figured it was PID related until I couldn't get any altitude, although its possible that multiple things are off.


The modifications include:
* Tattu R-Line 1300 mAh 75C lipo
* Favourite FVT LittleBee 20A ESC
* DYS BE1806-2300KV motors
* RAYCorp 4045 3-Blades 4x4.5x3 Propellers

Here is a video of it at full throttle.



Can I get some ideas of things to look at to track the issue down?