wont turn left

hi all my air boat wont turn left but will turn right on a six pence
both rudders have independent servos but the servos are matched and run off a y lead to one servo control
both rudders move left and right the same amount
i am running a pusher prop which rotates anti clockwise
any one got any idea's

It's to do with the rotation of the prop, the prop is aiding in the right turn but defeating the left, similar to prop walk on a boat. Only way to correct this issue is larger rudders, or increase the rudder throw so left becomes more responsive.

On a side note a single central rudder would work better and directing air throw, or setting up larger rudders to the outer edgers of the blade creating a funnel effect allowing the thrust to be directed better.

thanks for that it had me puzzeld
i will fit some bigger rudders on it this week end
at the moment the throw on both rudders in either direction is about 40degs
so i will have to reduce the right turn a little
thanks

well i made up a new set of rudders about 1/2 as big again
and hey the boat turns both directions now
thanks

Glad the solution was easily resolved