The thing I am wondering is, the standard Yamaha metal reed valves have the metal stops to stop them opening too far, these don't have anything so the petals can open up as far as they want, is this correct or should I have metal stops to restrict how far they open, see photo below s375.photobucket.com/user/kitkatjeff/media/CIMG2733_zps3f0af2ff.jpg.html if I need stops you cant use the Yamaha ones as they have two screws and these have 3 screws, they are also wider than the Yamaha ones but do fit into the barrels, thanks, jeff