| Author |
Message |
    
Newbolt
| | Posted on Sunday, October 14, 2007 - 05:42 pm: | 
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I have an 05 XB12R. Once it is warmed up the idle will not come down below 2K without bogging the engine. Once at idle it stays at 1000 to 1100 and is not rough. It runs fine, although the gas mileage has dropped a little bit.
I have lubed and adjusted the throttle cables. Checked for intake leaks and vaccum leaks, but found nothing. The TPS was reset about 1800 miles ago.
Were can I go from here. This is driving me crazy.
Any ideas would be greatly appreciated. |
Sparky
| | Posted on Monday, October 15, 2007 - 12:19 am: |
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I would lower the idle speed at the adjuster knob a little and see if that helps.
Also check if the rubber plug that covers the vacuum port by the throttle body is not cracked if this is not a Calif. model. |
Bombardier
| | Posted on Monday, October 15, 2007 - 05:00 am: |
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1000 to 1050 are the recommended settings |
Al_lighton
| | Posted on Monday, October 15, 2007 - 09:43 am: |
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This is a fairly common thing, especially on bikes with freer breathing intake and exhaust mods. The idle hang issue usually only occurs when hot. I've tried mapping it out and have not been successful.
During the warmer months, I keep the idle a little lower, 950-1000. This helps. During the colder months, it makes bike warm up a little dicier, so I bring it up 50 RPM.
I generally don't pull the clutch in coming to a stop on a hot engine until after the revs have dropped below 1700 RPM. Then it will drop right down. I don't even think about it anymore, so it doesn't bother me in the least.
Al |
Newbolt
| | Posted on Monday, October 15, 2007 - 06:32 pm: |
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Thanks for the replies. The vaccum port plug was cracked and I replaced it. I will try lower the RPM's a little and see. I have started to just come to a stop with the clutch out and that has worked. I was just concerned that something was wrong and I was missing it.
Thanks again, you guys are great. |
Bombardier
| | Posted on Monday, October 15, 2007 - 09:39 pm: |
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Al,
I read that the reason Buell says to set the idle at 1000 to 1050 is so the oil pump
is pumping the correct volume/pressure.
Below that I have heard it is not working effectively. Any comments? |
Sparky
| | Posted on Tuesday, October 16, 2007 - 01:06 am: |
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NB, Congrats on finding the leak.
I just love a story with a happy ending. |
Dentfixer
| | Posted on Tuesday, October 16, 2007 - 08:22 am: |
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I would like to hear some supporting data about the possibility of the oil pressure being too low at 950 to 1000 rpm. Anybody have the oil pump output numbers from the factory? What does the pump flow? Just might be some credibility to the theory since they updated the oil pump in 06. Perhaps it was just for the previous years?? Who can give us an answer? Please do. |
Al_lighton
| | Posted on Tuesday, October 16, 2007 - 09:50 am: |
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I have no data to back anything up. But nothing magic happens at 1000 RPM. It's a positive displacement pump. I have no doubt that the volume/pressure is lower at 950-1000 RPM than at 1000-1050 RPM. I just doubt there is any critical threshold that is exceeded there. But that 50-100 RPM idle reduction has been shown to help with the idle hanging issue, so that's what I and many have done. As always, go against the factory recommendations at your own risk. But the risk is minimal, IMHO.
The new 08 engine design may be a bit more critical in that regard. I can't think of any high pressure oil fed aluminum journals in the pre-08 engine. Everything is in bearings or splash fed bushings that I can think of. But the 08 has pressure fed cam aluminum journals from what I've read, so maybe those are more oil pressure sensitive than the earlier engines. They've also boosted the oil pressure by something like 12PSI, something that they probably couldn't have easily done with the old oil pump crossed helix drive design. But it's kinda moot as far as this discussion goes, the idle speed is now under processor control, there is no external manual adjustment. |
Dentfixer
| | Posted on Tuesday, October 16, 2007 - 01:10 pm: |
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Thanks Al. I trust your opinion. I've got another year on the warranty so I've set my idle low. It just feels better at a lower idle as well. My 06 has the race kit installed, it idles well and I don't even have trouble blipping the throttle like a lot of guys have complained about. |
Newbolt
| | Posted on Saturday, October 20, 2007 - 02:47 pm: |
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Al- you are a genius. I lowered the idle to 1K and have had no further issue with the idle hanging. The oil pressure light has not come on either. Thanks again. |
Moda
| | Posted on Thursday, January 10, 2008 - 09:42 pm: |
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Dear Sparky / Newbolt - ALL XBers:
I've too have experienced the hanging 2K idle on an XB12 with only 2K miles after warm-up. Can you inform exactly where the " rubber plug that covers the vacuum port by the throttle body" is located more precisely?
I see no such animal in the Buell Parts manual pictorials or part number items listing. Is it on the "Y" manifold? The cylinder? Where?
Please inform; if anyone can post a photo of the plug location, that would be great.
Thanks, moda |
Sparky
| | Posted on Friday, January 11, 2008 - 12:03 pm: |
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Moda, look at the third picture (says "Vacuum port that was plugged off") that Heyfred posted about his TPS mod. He installed a vacuum hose on the port fitting, but on a stock non-Calif model, the fitting should have a rubber plug on it. This rubber plug can age-crack and cause an air leak.
Have you found the idle speed adjuster knob and tried lowering the idle speed a hair? |
Moda
| | Posted on Friday, January 11, 2008 - 07:33 pm: |
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Hi Sparky:
Thank you for the fast reply. Also, my XB12 bike is a non-California model, I'm in the North East.
Yes; I'm aware of the cable-driven idle adjuster, but the bike idles perfectly at 1K until it warms up. I'm talking about 36 degree days, after slowly running the bike for 15 minutes, the idle floats at about 2K, so it is not overheating!
I'm fairly familiar with XBs and began doing TPS resets late in 2007. I do all maintainence. I've owned other XBs, but never had any act this way. This XB12 is 100 percent stock - NO mods at all.
I'm assuming you are referring to the 3rd photo from the bottom, since the 3rd from the top shows the PCV hoses that run into the airbox. In this photo(3rd from bottom), I see the "Vacuum port that was plugged off" note, and I believe this is where the hose is connected into the manifold and where the rubber plug would be on my non-CAL XB12.
Is this correct? Odd that the Buell Parts manual does not show the plug/port in the drawings. I'll check it out, but may as well order some plugs before tearing the bike apart...Do you know the Part Number of these plugs?
I'll search the manual again.
Thank you for your great direction Sparky!!!
Very Best Regards, moda |
Marks3tbillet
| | Posted on Friday, January 11, 2008 - 08:36 pm: |
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Moda:
My 2007 XB12X idle behaved like yours after my TPS reset. I figured it had to be related to the idle rpm setting. I lowered it with the cable and it all went back to normal.
When starting the bike cold and riding it was fine. Once warmed up, the idle would hang.
Mark |
Sparky
| | Posted on Friday, January 11, 2008 - 10:35 pm: |
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The plug/port is shown as a part of the Throttle Body Assy in the Induction Module - Electronic Fuel Injection section of the parts manual. I suspect that a rubber plug comes with each such TB Assy, and when the factory makes a Calif model, they replace the rubber plug with the Evap hoses and stuff.
So, to make it easy on yourself, improvise and take a short piece of fuel hose that fits on the fitting and plug the open end with something like a large nail head or screw and secure it with zip-ties. Or search the hardware or auto parts store for a proper size rubber plug. This is fairly standard automotive stuff.
After you have this buttoned up, you might want to do the standard intake manifold leak test that's mentioned in the KV here. Perhaps there's more than one gremlin lurking in the depths of that Milwaukee iron? |
Moda
| | Posted on Saturday, January 12, 2008 - 09:02 am: |
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Marks3tbillet & Sparky:
Thank you for your help; after fixing the plug issue, I'll perform the propane test for vacuum leak.
Thanks again Guys,
moda |
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XB will not return to idle