jetting changes with reed spacer

What kind of jetting changes can be expected after installing a reed spacer? Also I've noticed all spacers are the same thickness except for ESR's. Does the size of the spacer make much of a difference or is it more of a personal preference? I have some 1/4 inch aluminum and was thinking of making 3 or 4 of them and trying different combinations. Anyone had any experience with this?

 

I made one for my 1990 LT250R
Reed spacers create more distance for the fuel to atominize. You won't notice a differnce until you get to about 3/8" thick. Going past 1/2" wont help either. 1/4" gain is slight. I have not noticed any jet changes, but i think that it will run slightly leaner at full throttle.
Derek