What's the best target afr to shoot for on my k1 750?
The Honda 600's we dyno make peak horsepower around 13.3 on our wideband sensor
The Suzukis we dyno make peak horsepower around 13.1
The Kawasakis make peak power around 13.0
The Yamahas make peak power around 12.9
This is with Shell 93 pump gas, and the differences are strongly correlated to combustion chamber shape.
My GSXR 1000R, which has a two map switch, and we have done more research on, likes an ascending AFR that goes from 12.9 to 13.1 as RPM rises from 6,000 to 14,750 on 93.
On MR12 (Oxygenated race gas), this same engine likes a descending AFR from 13.1 to 12.7 over the same rpm range stated above. Keep in mind, the placement and type of O2 sensor, and the amount of leaks in your exhaust system, will all effect the number read which in fact is arbitrary, and generally not perfect on the dyno because your airbox and bike are not at speed with real world air flow and pressures.