Fuel mileage 14 or 14.5

[PoorUB]

I just had my '05 Ultra tuned and they set the fuel/air at 14to1. I asked for it to be leaner at cruise but the tuner refused to. My question, will that .5 make that much differance in actual MPG? The differance from 14 to 1 and 14.5 to 1 is ~3.5%. Will it affect mileage about the same % or more?

[FLTRI]

I just had my '05 Ultra tuned and they set the fuel/air at 14to1. I asked for it to be leaner at cruise but the tuner refused to.

Interesting that the tuner refused to do what the customer wanted without explanation?

My question, will that .5 make that much difference in actual MPG? The difference from 14 to 1 and 14.5 to 1 is ~3.5%. Will it affect mileage about the same % or more?

Actually the question should be: Will the difference in AFR make enough difference in running temperature to offset loss in mileage?
IMO the answer is yes, since we have these air-cooled engines without very good heat control to begin with, running 14.0 helps lower the combustion temps which in turn lowers the radiated heat you feel on a hot day, is what owners say when they add the Nightrider closed loop enricheners to their 07-up touring bikes. Your mileage may only go down 1-2 mpg at the most.

[Sonny S.]

IMHO the grooves change this.
If he was willing to go 14:1 @ WOT then he should be willing to go 14.5:1 at light cruise.
Non grooved I doubt 14:1 would be used @ WOT in the first place.

[FLTRI]

Sonny,
I thought we were discussing the AFR @ cruise?
IMO there is no reason, other than heat, to run richer than 14.5 during cruise whether you're groovy or not.
A couple questions come up:
Do grooved heads run cooler than non grooved heads with the same AFR @ cruise?
Do we have anyone who has measured the temp differences between 14.0 & 14.5 AFR @ cruise?
I think it would be great if someone with grooved heads could do that. It could be done in a controlled environment like a dyno cell or could be done on the street if the rider followed some stringent test procedures and had a Power Commander to make the change on the fly. It might be just what the folks here on the grooved fence need to see.
Bob

[Sonny S.]

Sonny,
I thought we were discussing the AFR @ cruise?

We are. I was just saying that if the guy was willing to go 14:1 @ WOT, he should have been willing to go 14.5:1 @ light cruise.
The groove comment is based grooved head bikes seem to be ok running a leaner mixture.
I think we are saying the same thing Bob, I just speak a different language.....and even I'm not sure what it is sometimes...lol 

[FLTRI]

I was just saying that if the guy was willing to go 14:1 @ WOT, he should have been willing to go 14.5:1 @ light cruise.

I agree and do tune some bikes, depending what type and how it is ridden, to 14.5 @ cruise. I do not use this AFR for land yachts due to their weight and aerodynamics. I fine 14-14.2:1 cruise afford a cooler running touring bike, and 14.5:1 works great for Dynas and some Softails.
Bob

[Sonny S.]

 

I'm also willing to bet that you would not go 14:1 WOT on a land yacht.
Now the only thing left is what you asked earlier..... Do grooved heads run cooler than non grooved heads with the same AFR @ cruise?

[PoorUB]

Your mileage may only go down 1-2 mpg at the most.

Do most here agree to this, at least?
In other words how much MPG will I gain if I get it leaned down to say 14.5? Enough to be concerned about it?

[Sonny S.]

Your mileage may only go down 1-2 mpg at the most.

Do most here agree to this, at least?
In other words how much MPG will I gain if I get it leaned down to say 14.5? Enough to be concerned about it?

Well, considering it's only me and Bob..... no, I disagree   
Just kidding, yeah it should only be a coupla MPG

[mayor]

Now the only thing left is what you asked earlier..... Do grooved heads run cooler than non grooved heads with the same AFR @ cruise?

well it wasn't a very scientific set of tests, but my groovy head 95" tw37 bike running mid 14's in cruise afr (CV44 checked on dyno) was at least 20 degree's cooler everytime (head temps measured with infra red temp gun) I compared to my brothers 96" stage 1 running at 13.5 or so cruise (T-max checked on dyno). Same riding conditions each test. Was it the grooves?  dunno.. I think cams and head flow may very well have an affect on that.