Just realized what model you have. Is it possible you have the blades on wrong? Even 1 on the wrong way will affect your lift. Slowly give it enough throttle to make the blades rotate. The blades should be slanted backward when slicing the air. Tilted lower on the backend as it spins. I don't think there's a pitch you can adjust and seeing as how simple those helis are, then I'm pretty sure it's your blades. It's very possible to install them wrong as I have done this before on the blade cx. And it's the same heli you have. just a diff brand. Opposing rotor helis are super simple.
If you still don't get it I can help you out if you're at the practice next Wed.