high idle RPM
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Outstanding HDF Member
Joined: Jun 2010
Posts: 2,015
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From: Moline, IL
i would rather do it myself i can, to prevent having to take my bike back to him and drop it off. its 45 min from me and im working 12 and dont have time to take it.
Club Member
Joined: Jun 2007
Posts: 45,429
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From: Bedford UK
That's understandable, but it is still worth calling them. If it is something you can do, they may be able to give you instructions over the phone. If not, then you can sort out how and when to get it to them.
Stellar HDF Member
Joined: Aug 2012
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From: Indiana, USA
OK- Here is why I say it is AFR
The idle is controlled by the throttle body and that apparently was not changed therefore if Air Fule Ratio was the same as before idle speed should be same as before. Lean Idle AFR will always generate a higher idle speed. In my opinion your AFR in low RPM's with little to no throttle is too lean. This is worsened by the cold start cycle which will teporarily raise idle until time or temperature is met then drop to fixed idle. Again all in the throttle body.
If you have the ability, document what you have now and add a little fuel in the bottom end then see if it makes a difference. If it helps maybe try a little more, if you go too far it will be like leaving the choke on and it will run rich and soot the plugs. Little steps then test are best If you are unhappy, put it back and take it back to the dyno dude.
The idle is controlled by the throttle body and that apparently was not changed therefore if Air Fule Ratio was the same as before idle speed should be same as before. Lean Idle AFR will always generate a higher idle speed. In my opinion your AFR in low RPM's with little to no throttle is too lean. This is worsened by the cold start cycle which will teporarily raise idle until time or temperature is met then drop to fixed idle. Again all in the throttle body.
If you have the ability, document what you have now and add a little fuel in the bottom end then see if it makes a difference. If it helps maybe try a little more, if you go too far it will be like leaving the choke on and it will run rich and soot the plugs. Little steps then test are best If you are unhappy, put it back and take it back to the dyno dude.
Stellar HDF Member
Joined: Aug 2012
Posts: 2,664
Likes: 184
From: Indiana, USA
Also - AFR is established with air flowing thru the intake and the injectors squirting fuel into the air making a stoichiometric AFR for gasoline of 14.7:1 Your new cams are lifting more with longer duration so now you have more air passing thru the intake. Assuming the bottom end was not adjusted, you now have a lean AFR so the injectors must pump more fuel to get back to the desired AFR.
Seasoned HDF Member
Joined: Jan 2006
Posts: 11,471
Likes: 2,998
From: Charleston, SC
I understand what you're saying about the AFR.
The only thing that confuses me in your approach (and I realize everyone here is just trying to help) is that the ECM will sense that it is over RPM and modify the butterfly (since these bikes don't have a Idle Air control valve) to lower the RPMs no matter what the AFR currently is.
Case in point, I can apply a -30, yes 30, to the fuel cells at idle and note that the engine sounds different, but it doesn't actually raise the idle because the ECM backs off the air flow automatically. Same if I +30. It just stays at 1000 rpm regardless.
So unless he has an intake leak the ECM should be able to account for whatever fuel mixture and control the idle anyway. That's my thinking. I dunno. This is why I'm thinking it's either set at a high RPM or there is a sensor proving a bad reading or leak somewhere. Just speculating of course.
lp
The only thing that confuses me in your approach (and I realize everyone here is just trying to help) is that the ECM will sense that it is over RPM and modify the butterfly (since these bikes don't have a Idle Air control valve) to lower the RPMs no matter what the AFR currently is.
Case in point, I can apply a -30, yes 30, to the fuel cells at idle and note that the engine sounds different, but it doesn't actually raise the idle because the ECM backs off the air flow automatically. Same if I +30. It just stays at 1000 rpm regardless.
So unless he has an intake leak the ECM should be able to account for whatever fuel mixture and control the idle anyway. That's my thinking. I dunno. This is why I'm thinking it's either set at a high RPM or there is a sensor proving a bad reading or leak somewhere. Just speculating of course.
lp
Last edited by lp; Jul 11, 2014 at 07:30 AM.
Novice
Joined: Mar 2012
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From: Florida
Thread Starter
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Outstanding HDF Member
Joined: Jun 2010
Posts: 2,015
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From: Moline, IL
thanks for the video, that saved me from having ot look up how to do it lol i will try this today after work first.
hopefully its as simple as making the adjustment. if not i will give the dyno a call monday
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Outstanding HDF Member
Joined: Jan 2011
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From: Western Illinois, land of bad roads, and corrupt politicians
This may be a dumb question, but, did you try doing a throttle reset yet? Ignition on, off, on, off, on, off.
Occam's razor...... All things being equal, the correct solution is usually the simplest.
Occam's razor...... All things being equal, the correct solution is usually the simplest.