Well my assumption that there was too much resistance in the pulleys themselves proved incorrect. I finally got another set of hands to help me directly test this last night, and even with a great deal of tension on the lines, the pulleys rolled smoothly. It turns out that the Ernst rudder itself is sticky.

I tried to lubricate the nylon-nylon contacts with Tri-Flow, but no luck. I think that I'll have to now modify the water rudder or make my own. I have no doubt that the Ernst rudder would function just fine if connected to a nyrod or the like, but in the stock configuration, and using pull-pull with kevlar lines, the movement isn't free enough.

I searched to see if others were struggling with a similar problem, but I found nothing. Anyway, I just thought I'd throw this out there to see if anyone had similar issues or whether someone has any recommendations for improving the movement of the Ernst rudder.