Tail wag in windy condition

[urgno]

have you checked this page ?

http://manual.spirit-system.com/index.p ... Servo_list
>> For optimal performance of the rudder, we recommend to set the Rudder Delay parameter according the table. <<

[ZeXx86]

If the tail wag is actually tail hunting - the boom is moving from side to side slowly then the problem can be too high Rudder Delay.
But in the most cases it is unfortunately a tighter mechanics.

The smoother the mechanics, the less apparent the effect of wind.

[urgno]

as ZeXx86 suggest check also the tail mechanic
disconnect the tail rod from the servo and try moving it with you hand
the mechanic have to move freely and smoothly