Originally Posted by Poolside
That's the thing about the 14.7 stoichiometric mixture, it isn't optimum. Electronic Fuel Injected and catalyst-equipped motors aren't operated at 14.7 either. Instead the mixture is cycled above and below stoichiometry. Which alternately creates an oxygen-rich, followed by an oxygen-lean, exhaust. The alternating oxygen-rich to oxygen-lean exhaust is necessary to operate the catalyst.
Yes, agreed it switches between something above the set point and something below it. When I use the term setting closed loop AFR to 14.2
, I mean that's the center of a range, the average AFR. In the case of 14.2, I'm running 13.7 to 14.7 at the moment but am still conducting tests.
Today I kept boosting AFR to see when the idle stumbled. Also noted that after a couple days of running 14.2 the bike is idling faster. Like it's cleaner. (?)