How do you know that is the problem. No you don't just tweak them. Do you know how to set breaker points? The reluctor gap is set the same way. If you look down in there is a screw to clamp one end of the assembly, with a sort of slot. You slightly loosen the screw, preferably using two screwdrivers, one in the adjust slot and one on the screw. Move it just a bit, re-snug the screw and see where the adjustment is.