Curious on the shims, currently I have the two stock shims on it, one .28mm the other .32mm for an effective .60mm, and the extra shim in the box is .42mm. The engine has a bit over a gallon on it, would putting the single .42mm shim on it help with tuning at this point?

If it helps, I live in Northern IL and for the last couple months it's been high 70s up to mid 90s, humidity between 5- and 40%. Thanks for any insight.