OK, here's the problem as I see it.
The stoichiometric ratio for gasoline is 14.7:1. That's what the EPA has mandated (and the MoCo blindly follows) that the ECU has to be calibrated to.
The stoichiometric ratio for ethanol is 9:1.
Here's my querey: in Oregon, they use a 10% ethanol fuel so that drops the stoichiometric ratio to 14.1:1 or so. That makes the EPA levels running way to lean for even the stock and Stage 1 ECU settings.
Why can't the ECU itself be recalibrated by the MoCo for available fuels in the region where I live? I don't want to have to buy add-on tweakers (PC, RideMaxx, Terminal Velocity, et al) just to get her to run right. For the money I already spent on her, she should run right straight from the factory, without haveing to spend another $500-$1000 for fuel management.

 

Flex fuel vehicles do exactly what you want as they can sense the type of fuel being burned. Our motorcycles can not. You have three options:
1. Use only 100% gasoline
2. Buy a fuel programmer or software
3. Live with it as-is
I voted for #2 and I use the TTS Mastertune. These are the realities. Spending another $400-$500 for the programmer or software may not be desirable, but the benefits are well worth the cost and will make your expensive motorcycle MUCH happier. It is just part of the cost of ownership.

 

Isn't that the purpose of the O2 sensors? It's not actually measuring the afr, but rather the afr is implied by the composition of the exhaust gases relative to air. Rich burns produce carbon monoxide, lean burns leave free oxygen. That's true irregardless of the actual afr of the stiochiometric ratio since that's effectively the definition of the stiochiometric ratio, i.e. just enough oxygen to completely burn the fuel.

 

Likely any wide band sensor will adjust. Problem is stock Harley uses narrow band for idle and constant rpm with limited range. At least that's my take on it.
Ron

 

It still indicates whether you are above or below. The only issue is how far the ECM will adjust the fueling to achieve the target afr, or, actually, bias voltage.