Martu,
If I remember correctly, go to the F/S menu.
Now move your throttle stick to the full throttle position.
Now push the set button/wheel (?)...the F/S setting should sy 100%. At idle it should say 5-20%. With idle trim at zero, should say 0%.
Play with the buttons and you will go "OH! *****! Why didn't I think of that! (I have to play with it each time I set up a new plane.....
Hope this helps.
Greg