Power & Performance ALWAYS, with smoke trail, how thick or how thin it is, well that will depend on the fuel you run, and you can usually hear it one way or the other if it is too rich or too lean, if power starts to drop off during a race when below 1/4 tank then your too lean.

I only spit test mine after a race before shutting it down, for self assurance I'm not cooking anything, and if it stays idling until I get it back to my pit table then the bottom end tune is good too.