Originally Posted by lh4x4

Bob had it exactly right. The EMC has the lean burn standard programmed into it. The EMC checks every so many seconds when in closed loop the O2 content of the exhaust with the narrow band sensors. If the amount is under or over the EPA required 14.7:1 level the EMC adjusts it back to the standard.

That is why one can change the intake and or exhaust without the need for a tune. When they are changed a half hour ride will have the bike running the correct AFR. As said other changes require a tune to get the full effect.

The stock EMC does not adapt in any other manner while riding except ( always there is an exception) The spark curve is set to make the use of 91 octane. If you use anything higher it does not do crap for that higher octane. However if you use lower than 91 octane the EMC MAY reduce the sparks advance when detecting knock. But only for a set time period and it will revert back unless more knocking. The TC motors used ion sensing and retarded the spark 10 degrees {if my memory is correct). M8 engines were improved to sound detection as it is more responsive and the EMC only retards the amount needed and not a single set amount as in the past. It is more precise and much more responsive.

So the stock EMC only impacts AFR and spark advance. One needs to have a tuner to change maps particularly to have a power AFR.

That feature was not 2014 and up. It has been a feature with the first fuel injected H-D bikes. Lean burn H-Ds went back to around 78. My 80 FLT had the jets changed and crankcase vented to the atmosphere the day the first owner picked it up. He also had an oil cooler installed. That is why that AMF Shovel starts and runs so great today at 61K.