They dial in better starting on the rich side and learning to lean out. Nice tuner but still lacks IMO if you're fortunate enlighten to have someone near you that will use something like a TTS MasterTune instead. The things I don't care for about the TMax is email correspondence (not that a dyno operator like our shop has that measures actual power at all throttle adjustability points, they are not capable of pulling timing if you get a bad tank of fuel, they're not exactly a cheap product, and they don't have some of the nice fluff tables that really make a tune shine such as throttle progressivity etc. and last but certainly not least, they are only targeting a predetermined AFR. That Afros not necessarily where that bike performs best and the power is linear the ought the rpm range as it should be if tune right. One last thing, I prefer to rely on more than just one reading (oxygen) and a strain gauge to measure power in real time that shoot for a target AFR. Nearly every bike on the planet has reversion at some point in it's rpm range depending on exhaust, head ports, cam timing events length of pipe etc and when reversion occurs, the oxygen reading is skewed and will falsely tell the operator to add fuel. Is it's already too rich there to begin with, power will decrease with the rich condition.
There's 20.9% oxygen in the air we breathe. There's no CO (carbon monoxide) which are molecules of partially burned O2 and HC (Hydrocarbons) which is gasoline. Have readings of HC, CO, CO2 (completely burned oxygen and hydrocarbons) works great in the classroom but if you ever riddent a stock bike with a cat in the exhaust, you know they suck for the real world. The term used for this completely burned up mixture of HC's and O2's that works in the classroom and perhaps liquid cooled variable valve timing motors, sucks big time for out V-Twins. It creates heat, lazy throttle response, low power, heat and more heat which happens to be the enemy of an air cooled motor. Having 4 gas and a live reading of measured HP and TQ (not a calculation that is one size fits all for parasitic losses whether you're tuning a 50 cc dirt bike or a big V8 chopper with a 300 mm rear tire and a billet wheel that outweighs the entire 50 cc dirt bike doesn't seem nearly as up to snuff as some of the tuning modules are getting. Understand combustion chemistry is just the first step to executing a seamless tune. Standing and holding the throttle until a "safe" AFR is achieved is not much of a tuner in my book. Especially since the same AFR can be achieved by retarding the timing and taking fuel out or advancing timing and adding fuel with that advanced timing. 4 gas a da love reading measured with a strain gauge takes the guess work out and you can rest assured your bike runs to it's best potential for the components it has on it. There's no guess work, it tell you what to do with the timing and fuel and some bikes more or less than another but you have a live reading of power so kinda hard to screw that up.