Open throttle
 

I just installed a different radio and reciever on 3.3 revo steering is fine now that I adjusted the position of servo horn. The throttle is staying open now doi have to adjust throttle servo horn also to correct this problem

take the horn off and re center then adjust trim on radio if need be

Set the radio trim to neutral before you re-center, other wise its already off by the amount of the trim.

I think he needs to reverse the servo action with the small switch on the tx..