RE: Prather Funcruiser won't turn
Has it been in the water yet? Yeah, I know that this might be a dumb question but you might find that it doesn't need as much as you think if it hasn't been wet yet.
If it doesn't turn well and you can't go any more with the present setup then the linkage should be hooked up to the furthest hole out on the servo arm and the innermost on the rudder.