My gas mileage improved 16 mpg when I dipped carbs in water and vinegar and changed all the orings. Changed the emulsion tubes too.
Used the Factory nickel plated ones. I got the O-rings from O-rings Inc.
The O-rings listed below fit on 36mm carbs from a '90 GSXR-11
This thread in the search function helped me to find all the O-rings.
Re: BST36ss Carb o-ring sizes.
3mm x 1mm bn70 for mixture screws
3.5mm x 1.5mm bn70 for top cap
5mm x 1.5mm bn70 for small float post
7.5mm x 1.5mm bn70 for large float post
8mm x 1.5mm bn70 for can't remember (maybe the T fitting between carbs?)
10mm x 1.5mm v75 for bottom of slide guide