orion- lrp problem

[tomi30]

Hi I have a orion pro 2-3s and before I had it with a 6.5 vst but was very slow and I just bought a lrp x20 4.5 but I have a problem, is that the engine is only revs to the middle the throttle suddenly doesnt respond and suddenly works again and revs to the end and suddenly doesnt respond and revs to the middle and do this all the time ... I updated the software of the box and the esc and have recalibrated esc anyone know why that is?