You'll be drilling out the mixture adjustment screw to ba able to adjust the mixture. Kit has a heavier spring, and replaceable jets. Best way to get the jetting right is at the track or a dyno. There should be a range of jets to use on an 80" motor. Trial and error til ya get the fastest track time and good burning plugs!
Hoist!
There we go...I wasn't sure what the kit came with as far as jet sizes. So, they vary in size for the particular motor; in this case the EVO
Got a fairly good grip on the trial and error part from all the reading of various links and sites I was refered too; just didn't grasp the jet sizing part of the equation. I was tryin to picture in my head how the kit manufacture knows which jets to include when I order; but, I gather because the stock motors are all jetted basically the same depending on year , model, etc; the manufacture knows this and provides varying sizes larger/smaller than the stock jets for the builder to work with.