The best thing you can do to the counterweight is remove it, drill out the weight from the mount with a 3/8" bit, and stack 15g fender washers on. The stock weight is around 200g, I found the ideal weight with a short throw shifter was 130g, or 7 washers + M10x1.25x30mm bolt. Get all zinc platted stuff from Homo Depot and it'll look good, too.
The benefit of using washers is you can customize the weight until you find the right oomph to pull through the gears. We all have different expectations.