O.k. heres my situation

I have an hitec optic 6 radio system an a 4 star powered by a magnum 52 4 stroke. Whats happening is when I throttle up on the stick, full throttle is reached when the stick is only a little more than half way. If this was any other channel I would just add some expo and it would fix the problem but with it being the channel for throttle expo is not an option. Now I could fly it as is and just keep in mind that half way on the sticks is full throttle but I would rather have it were full throw on the stick is full throttle. Any advise????


Thanks