Just a few questions on dyno tuning

How is the mixture of a 2 strokes jetting measured on a dyno?
Is the exhaust analyzed like a 4stroke? o2 sensor
Is the mixture measured by exhaust temperature?
or is it gauged by peaks and trough's in the power output and torque curve?

if anybody knows of a good 2stroke tuner in south east Queensland (nsr experience would be good) please pm me thanks