Sounds like good advice v8jon, thats what I desided to do. Put 60 degrees cw on diaphragm, seams to be the best with 2 turns on the smoke screw. At 90 degrees on diaphragm its quicker but smokes to much, and at 120 it smokes less but starts to return to normal power. I also tried 6o degrees ccw, boy it slowed down to the point I thaught "what have I done"!
I wonder what can be holding the diaphragm in mine, has nobody else had this problem? It definately comes to a metalic solid stop, and I am not brave enough to force it beyond this point... thanks for the tips.