Rc plane help
 

A while ago i bought the nitroplanes fiberglass f4 phantom and have been working on it, but cannot seem to get it to move. Is it a weight problem? It might weigh around 7 to 10 pounds, but i am using the recommended jets: 70mm which are 3000kv each and it seems to be powerful like it wants to move but can't. Is 3000kv enough? I have covered every air spot so it is air tight. Really need help!