Dear fellow xt660-riders,

I've already read alot of different CO-topics.
But i still find it hard to understand the whole CO setting/adjustment.
I ride a 2006 (so no o2 sensor) Xt660r, completely stock.
I do understand how to change the CO setting. I do know to make a note of the CO number before changing it, and that every xt can have a different CO setting from the factory ranging between -128 and 128.

But.. if i want to change the CO, how can i possibly know wether the previous owner didn't change it already?
Currently it's set to 25, can i up the value without any consequences to the engine?

And most of all: what does it actually do? Does it trick the ecu/engine in some way?

Kind regards from Holland