hey all i just finished my mx 400 ( my first heli that wasnt bought ready to fly) and i couldnt get my futaba 7uaps to work correctly so i went out and bought a 6exh specifically designed for helis .i have everything set up but im having problems understanding the pitch servo.i went by the book and centered the servo and then adjusted the rod to achieve a horizontal position on the pithc tray.now when i add rpm the pitch servo moves with the throttle ( normal i assume to achieve the correct pitch with rpm) but it only lifts for a minute then the pitch is too much and it starts push the heli down i know i have it set up wrong i just dont know how to fix this . im obviously very new to this but trying to find info on this stuff is hard

Sounds like the pitch servo is reversed or your pitch may not be correctly setup.

Do a google search for "trex video ccpm setup part 1 2" (without the quotes). Granted, you don't have a TRex, but the MX400 is similar. There are some good videos out there on how to set up the model and ensure the build was correct.