Tuning is not a huge mistery! You are adjusting a ratio. There is a prime amount of both air/fuel to make good power. The ex-tech cylinder is no different than any other from that stand point. Its hard to explain in a forum, but the concept is so simple. Fuel is needed to cool things down, but you dont want it so cool that its not burning all of it. If its fat, it can't burn all the fuel on combustion so it flogs it out the pipe, and its lazy. Lean on the other hand lets it get really hot, builds a huge fire, but it makes insane power, for just a second, there is the fine line. Keep runnin it lean it will eventually distort, gaul, melt the cylinder,piston, plug what have you.

I cant tell you, set your screw here, and here and it will be perfect. Elevation matters, type of pipe, fuel used, ambient temps, aif filter cleanliness, and even moisture in the air effects the tune.

Temps are good way to play it safe, but watch your smoke stream, feel the pull and you will dial it in, if it is just extremely blippy with no smoke, she be lean. Also, tuning the bottom end needle helps you off the snap, so you may not have to turn the top, and vise versa. Its a balancing act, but its not a hard one.

one thing to keep in mind, if you tune it to be nice and crisp as soon as you fire it up, its gonna go lean on ya as it warms up. Dont turn screws until you have made a lap or two, then start tweakin, small turns at a time.

MY OPINON, NOT CLAIMING TO KNOW ANYTHING!!!

One other thing, the BAT pipe from ex-tech, watch for the internal baffle coming lose, heard of it, and seen it happen MANY times. Seen it once, but heard SEVERAL folx with the issue.