I have a Morris Su Do Khoi ARF. At the points where the pull-pull cables exit the fuselage, they bind. I've tried changing the angles by moving the control horns and the rudder and elevator servos to no avail. I've also tried various amounts of tension on the cables.

This is a problem because the rudder and elevator are very stiff and won't return to center when released. This makes it very difficult to control the plane - especially during high-alpha flying.

I'm using the stock plastic coated cable that came with the kit. I've considered using a more flexible kevlar cord, but I can't get it to thread through the tubes. Is there a trick to getting the cables right or to installing kevlar instead?