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[Dead_Reckoning]

What is a good Fuel Air Ratio?

18 months ago I had my 03 SERK Dyno Tuned by and HD Shop. The Fuel / Air Ratio was a straight 13:1 acrossed the board.

Recently I replaced the HD Stage 1 with a Doherty Power PACC.

I went to and Indy Shop that has been doing dyno tunes for about 20 years. I had them doa quick run to see what my Fuel / Air ratio is now.
It turned out ti be 12:9 to 13:0 and no longer a straight line across the board.

It ran very nicely at 13:1 and runs nicely at 12:9 - 13:0

The Dyno Tuner is suggesting that I may want to have a new dyno tune to 13:4 or 13:5 and claims that is a good F/A for Harleys.

My question is "What do you feel is a good F/A Ration?"

[hawgzilla]

There is no one number for a good air/fuel ratio.  I would guess that what you are looking at is only a full throttle pull.  If that is the case then around 13:1 would be close to ideal.  If you are actually running 13:1 in all ranges, then I bet your fuel mileage sucks!   Part throttle/ light loads the a/f ratio can be quite lean (~14.5:1).  The more load you place on the engine, the richer it needs to be.
I generally tune for 14:1 at part throttle and start going richer at higher loads/ throttle positions (>60% throttle and higher). 
The part throttle settings are FAR more important then just the full throttle settings.

[Steve Cole]

Typically a TwinCam engine doesn't much care if the mixture stays between 13.5 and 12.8 as far as power output goes at WOT. You might see a couple of HP difference across that entire range on a dyno but one needs to remember that the dyno runs from one to another vary by 2-3 to start with. So with that in mind if your bike is running good and YOUR happy with how it runs and rides I would not worry about it now. If you make more changes later it would be time to look into it.

[Dead_Reckoning]

Typically a TwinCam engine doesn't much care if the mixture stays between 13.5 and 12.8 as far as power output goes at WOT. You might see a couple of HP difference across that entire range on a dyno but one needs to remember that the dyno runs from one to another vary by 2-3 to start with. So with that in mind if your bike is running good and YOUR happy with how it runs and rides I would not worry about it now. If you make more changes later it would be time to look into it.

Thanks
I was planning on waiting until I add the S&S Headers and maybe some headwork

DR

[Dead_Reckoning]

There is no one number for a good air/fuel ratio.  I would guess that what you are looking at is only a full throttle pull.  If that is the case then around 13:1 would be close to ideal.  If you are actually running 13:1 in all ranges, then I bet your fuel mileage sucks!   Part throttle/ light loads the a/f ratio can be quite lean (~14.5:1).  The more load you place on the engine, the richer it needs to be.
I generally tune for 14:1 at part throttle and start going richer at higher loads/ throttle positions (>60% throttle and higher). 
The part throttle settings are FAR more important then just the full throttle settings.

Thanks
Yes, that is what it was tuned at 13:1 across the entire rpm range and Yes, the Fuel Milage has sucked compared to what it used to be.
As suggested elsewhere, I am going to wait until I do some more upgrades and then retune it.