Doug
The locatation of the rebound adjuster should be backed all the way prior to installation on the YZ. Before you install the fork cap on the piston rod just make sure that there is spring tension on the rebound adjusting rod and that it will push down almost flush to the top of the piston rod.
You should get about 10 full turns of the fork cap before it bottoms on the piston rod (make sure it is not botoming out on the jam nut), this is a good way to check that you have full thread engagement.
Take Care, John