Do i turn the valve - or + to put less pressure on the rear brakes. I tried both ways and cannot tell a difference.

 

(-) would be less. It should take quite a few turns to make a large difference if it's a good prop valve.

 

will try tomarrow...

 

I have to check on mine but every valve under the sun usually works in such a way that it closes when you close it (as in turn it clockwise).
So if the valve is fully open (aniticlockwise) you should have the most brake pressure at the back ... just a thought, but need to verify as well