You take the lid off the airbox, take it to a dyno shop, tell them you want 12.75:1 for all WOT operations. 13.8 - at low loadings/throttle ops tapering down to 13.2:1 for higher loadings and throttle settings - then taper down to 12.75 as throttle settings go beyond 60% - with 12.75 being hit by 85% throttle position..

They may protest the part throttle fueling I suggest - and if they really know what they are doing, it's ok for them to "do their thing" in that RPM/throttle/loading range..That area is concerned with driveability and fuel mileage only.. However, 12.75:1 for all wide open throttle operations is non-negotiable..

Believe it or not, many "tuners" are complete morons - E.G. With no knowledge of how AFR affects flame front speeds.. Ask your tuner what they think your lidless airbox and barker exhaust will do to your engines' VE - see how they respond.. (VE = volumetric efficiency, but they might even know THAT! ).. A correct response would be something like "typically, those mods will significantly enhance VE in the upper 1/2 of the RPM range at WOT but the cams will determine the exact results"..

P.S.
Anywhere VE is enhanced (over stock) additional fueling would be required..
Assuming you have the full Barker exhaust system, and if they do your tune right, your bike becomes an "animal" compared to before...

 

 

One more bit of advice... If someone says " just one more drink", don't do it. You'll just wake up wondering "How did I get here? And where are my pants?"

 

 

 

Yes, my testing settled on those targets. That is probably all you wanted to know, so I'll not elaborate..

Carb or EFI ? This question makes no sense - The type of fueling system is irrelevant..

To talk any deeper about AFR will probably be counterproductive.

Just remember, most "tuners" are not the sharpest tools in the shed. Ask your friend/tuner/etc - What is the relationship between AFR and ignition timing ?

P.S. The right answer is that richer AFR's require less ignition advance, leaner AFR's require more ignition advance.

 

 

Yep, complete dumb asses... But dumb asses usually have dumb *** reasons for their dumb *** advice - which could be really funny to hear...?

Just a little primer : AFR = air fuel ratio. 12.75 : 1 - 12.75 parts air to 1 part fuel. Whether that is being created by EFI, carbs, or spraying fuel out a spray bottle into the intake tract, it's all the same to the engine..

 

Would you recommend the same AFRs with a 351 big bore?