I completely appreciate what you're saying, but I have to disagree with 10% variance being a worthy mixture ratio balance goal front to rear. I believe you meant that 10% as more of a concept than an actual number because right now I'm within 10% and I have about one full ratio point difference front to rear.

Looking at my a/f data logs and the constant, slight variance in mixture within a single cylinder at a relatively steady RPM & throttle position, I can see that it's impossible to tune to perfection, but I am hoping to get closer to a 4% mixture variance front to rear. At 4-ish% variance, with one cylinder at 13.5. The other could be as low as about 13.0 or as high as about 14.0. Being the utter tuning novice that I am, I don't know if that's realistic but I'd sure like to think it is.

Of course I realize that tuning to a target AFR is never going to result in that ratio being precisely, consistently met, but is more of a target average or mean.

 

Bob, I think that's great advice. I've watched tuning sessions on 2 of my Harleys but never close up and personal. When I go back for my post break-in session I'll see if he'll let me get close enough to the action to really see what's going on.

 

 

Remember that the Sensor measurement is called Engine Temperature on a TC. HT is just a calculated value by the ECM. The calculations were done on a stock engine so while it's better than nothing donot expect its reading to be correct on a modified engine.

 

Point taken. I've increased the displacement of my engine by about 14%, so I would expect it to run hotter, and I also expect to generate more heat from the characteristics of the new cam profile, though I'm not solid on how accurate those statements are.