by L screw do you mean low ? or limiter ? because its the H limit screw you have to adjust.

as for the spacer, you cannot remove it, since the plastic sheeth between the cups will get crushed, and you cant really move it onto the non drive side cup because their wont be enough threads inside the frame.

what frame and what mech are you using ?

P.S. this should have been posted in bike mechanics instead of mountain bikes, youd get a lot more attention in there...