Need Help - Popping

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Jun 19, 2008 | 12:13 PM

mikef

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Cruiser

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Need Help - Popping

I had my Dyno Tune done with the SERT.&nbsp\\;\\\\\\; My results are posted below.&nbsp\\;\\\\\\; It has been a few weeks since I had it done.&nbsp\\;\\\\\\; My problem is that it seems to be popping more now than before the Dyno Tune.&nbsp\\;\\\\\\; From what I have been told and what I read here the popping would be eliminated with the Dyno Tune.&nbsp\\;\\\\\\;
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I have been thinking that it might clear up or maybe it was normal.&nbsp\\;\\\\\\; But then yesterday I went for a ride into the mountains.&nbsp\\;\\\\\\; Once I got up in elevation the popping went away.&nbsp\\;\\\\\\; But then it came back when I went back down in elevation.
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Any Ideas????&nbsp\\;\\\\\\; I am going to take it back to the shop but I wanted to see if anyone had any ideas first.&nbsp\\;\\\\\\; Thanks guys.

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Jun 19, 2008 | 03:17 PM

priceamp

Road Captain

Joined: Jun 2006

Posts: 581

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From: Portland, OR

RE: Need Help - Popping

You should post this in the Electrical/Ignition/Tuner section and hopefully Doc, the Dyno guru, would answer.
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Assuming you are referring to popping when de-accelerating or between shifts, it sounds like you have a lean air/fuel ratio mixture at 0 and maybe 2 percent throttle positions. Case in point, when you went up in elevation, the air gets thinner and AFR get richer and decel popping went away. I had the same problem and increased the VE tables by several increments from 1500 to 6000 rpms for both the 0 and 2 percent throttle positions. This makes the ECM think the Volumetric Efficiency in this range is greater, ie, more efficient, and thus the ECM adds more fuel to maintain the AFR, which in effect richens the AFR mixture.

Jun 19, 2008 | 03:23 PM

mikef

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RE: Need Help - Popping

Yes the problem is when I left off of the throttle....
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I figured it was running lean too.... but when they did the Dyno Tune they made the mixture richer....&nbsp\\; Now the popping is worse.&nbsp\\; So that made me think that may not be the issue.&nbsp\\; Does that make any sense?

Jun 19, 2008 | 04:52 PM

squirrelu

Cruiser

Joined: Mar 2008

Posts: 171

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From: new haven,ct

RE: Need Help - Popping

so fatit up and see what happens is it carb or efi/////efi sucks more fuel more air more power

[IMG]local://upfiles/55565/77A484553CAE4103A558550157CCA021.jpg[/IMG]

[IMG]local://upfiles/55565/87764D3A5AFA499D8AA10EB5E0ABFA53.jpg[/IMG]

Jun 19, 2008 | 05:18 PM

mikef

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RE: Need Help - Popping

It is a 2008 with EFI.....

Jun 19, 2008 | 06:41 PM

WARG

Elite HDF Member

Joined: Jan 2006

Posts: 4,357

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From: The Lone Star State

RE: Need Help - Popping

The A/F ratio on your dyno sheet looks good, you may just need some tweeks at certain throttle positions.&nbsp\\; Your dyno guy should make the adjustments for you, no problem.&nbsp\\; Sometimes tuning is a process, not an exact science.

Jun 19, 2008 | 06:44 PM

priceamp

Road Captain

Joined: Jun 2006

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From: Portland, OR

RE: Need Help - Popping

Quote:

I figured it was running lean too.... but when they did the Dyno Tune they made the mixture richer

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Yes, you're right that a Dyno tune typically on newer bikes will always decrease the AFR, or conversely, add fuel. Looking at your fuel curve the tuner set the AFR at the typical 13.8 ratio, but notice that the curve(s) don't get to 13.8 until after 2700 rpms. So I think, typical of tuners, he focused on max power and torque and ignored ride-ability. He did achieve a nice value torque by the way. I'd contact the tuner and tell him he's got more work to do. Getting rid of the decel pop will not reduce your HP or TQ.