My Scorpion 4035-250 is happy with the XOAR 18x12. She can prop hang too, if necessary. As for the trust line I need some help here. How do I know my rudder is STRAIGHT when there is no counter balance? I suspect my thrust line is an issue and not the rudder but how does one be sure on that front? I mean if the rudder is say 3-4 degrees out to maintain a straight vertical then its obvious on the rudder but if its like 2 degrees how does one see it without the counter balance?