I think I might have seen something from Kitfox which recommended a higher initial setting for the angle. Of course you set it at whatever it takes. Whirlwind may even be aware that the recommendation is a little too fine and just haven't gotten around to changing it in their installation documentation. Wish it wasn't so, but that is not unusual for many companies, in my experience. Just out of curiosity, have you checked the accuracy of your tachometer?