Just put new rx in car

[Crazy L]

...and came across a bit of a problem, not did I have a mare binding it (not that that's the bit that's getting on my wick, oh no).

I'm running a HW 120 esc, was used for one race meet in November last year at the MK gp, and my car broke in the final so not touched it since, as I've been after a new radio (sanwa/ko etc) to replace my Core Code system, anyway, no bargains later so I bit the bullet and bought a new rx.

Bound it up but now when I turn the car on, it throttles up for about 5 seconds untill it finds itself, it's getting on my tits a bit.

Do you think it could be a rx issue or to do with the esc?

Thanks in advance