In general a lean mix will run hotter, more complete burn in the chamber; and a rich mix will run cooler, burn is incomplete and continues into the headers which have more exposed surface area and can shed heat more efficiently.
Of course, this depends on what the reference point for lean vs rich is. If you're already very lean, leaning just reduces the amount of fuel to burn, less heat overall produced; and riching just increases the amount burned, more heat overall. Peak efficiency though will be somewhere in the range where leaner is hotter and richer is cooler. Which is a little ambiguous, since you reach a point where richer is just flooding.
Unfortunately, this bike having a cat means you can't really use an exhaust tester to tune fueling as finely, ideally you get a complete reaction with high CO2:CO ratio by the exhaust opening. Though you could still get it pretty close if you tap the headers, if I recall correctly you want <1% residual hydrocarbon at 1 inch past the block.
With regard to ambient temperature, depending on how extreme a temperature difference, cool air is denser and you'd want slightly richer, but unless you demand extreme performance, you can trust the ECU to manage this.
Last edited by USSENTERNCC1701E; 05-14-2016 at 03:29 PM.