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Full Version: CB1100 Idle speed instability problem
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Ferret, have you tried the same thing with the bike on the center stand?

Could be the clutch is engaging at or before the point where the switch changes contacts and becomes hard to spot when in gear and moving or pulling away.

Think Doc means when the lcbs joins inversely against the iclsdg causing the sttlm to slide over the rdl track Dodgy Huh?

Thumbs Up max
(04-06-2018, 02:24 PM)max_imp Wrote: [ -> ]Ferret, have you tried the same thing with the bike on the center stand?

Could be the clutch is engaging at or before the point where the switch changes contacts and becomes hard to spot when in gear and moving or pulling away.

Think Doc means when the lcbs joins inversely against the iclsdg causing the sttlm to slide over the rdl track Dodgy Huh?

Thumbs Up max

That's certainly what I thought he meant. Huh
Max no, I may do that sometime although that would make it hard to tell when you are at the friction zone of the clutch engagement I would think. I only try these things because others bring them up and I want to see what they are talking about.

Just for the record I am not having any issues with my bike, at 37,000 miles + it still idles and runs perfectly.
Well... I'm gonna blame this thread for my '14 standard getting infected with the high idle issue. Mine started after a refuel so I'm hoping for change after burning this tank. If not, could someone give me an executive summary of the 79 ages of this thread?
Sure... It's not looking good for Nemo
(04-09-2018, 10:02 AM)Nemo_imp Wrote: [ -> ]Well... I'm gonna blame this thread for my '14 standard getting infected with the high idle issue. Mine started after a refuel so I'm hoping for change after burning this tank. If not, could someone give me an executive summary of the 79 ages of this thread?

Nemo, sorry to hear this as one who suffered through this for 6 months and then traded in my '14 standard as a result. I find it interesting that it started right after a refuel, as mine did too. Had never happened before--I filled tank before heading home after an hour ride, and upon starting it up, idle shot up to 1500 and stayed there. Over the next few months, high idle, low idle, back an forth, eventually, low idle was more common.

I posted this before as a "summary" of the spreadsheet where owners describe the problem and "fixes":

What members have done:
1. throttle assembly replacement, under warranty (more than $3,000 if not under warranty). Problem solved.
2. One IACV replacement worked (under warranty, would have been $1,300), one didn't--I think this one was performed by the member
3. WOT riding...worked for some, didn't for others, temporarily "worked" for others
4. battery replacement seeme to "fix" for one member; others have disconnected battery, recharging, problem returned.
5. TPS reset; worked for some, not for others.
6. Wire at TPS connector was crimped? "Fixed" and problem went away (I'm not sure of the details).
7. EOT replaced, didn't work for a couple
8. EOT unplugged, problem goes away, but then comes back.
9. sea foam added, fuel injector cleaners; some say this cured issue, for other no
10. ECU reset; worked? for others didn't
11. TPS disconnect, clean
12. some just live with it?


SportsterDoc has a summary of "to do" list back on [url=http://cb1100forum.com/forum/showthread.php?tid=8120&pid=190507#pid190507]post #651

Good luck with it.
Hi Nemo and thanks pdedse for the list, actually 2 iacv replacements have been succesful, johnf replaced by dealer and magnus done by himself came right after some time after replacing iacv, both are still fine to date.
Dave is in the process of replacing his iacv and would be the third one if succesful, as you may know the iacv is not expensive, just a lot of work to get to.

What may help you in the mean time is using the "engine off" switch on the right handlebar when it has high idle, it resets the iacv position among other things.

It would be interesting to know for us if the high idle is present all the time or starts some time after the engine is warmed up, so starts at 1500, settles at 1050 and then gets " stuck "at 1500 again after some time?
(04-10-2018, 05:13 AM)max_imp Wrote: [ -> ]Hi Nemo and thanks pdedse for the list, actually 2 iacv replacements have been succesful, johnf replaced by dealer and magnus done by himself came right after some time after replacing iacv, both are still fine to date.
Dave is in the process of replacing his iacv and would be the third one if succesful, as you may know the iacv is not expensive, just a lot of work to get to.

What may help you in the mean time is using the "engine off" switch on the right handlebar when it has high idle, it resets the iacv position among other things.

It would be interesting to know for us if the high idle is present all the time or starts some time after the engine is warmed up, so starts at 1500, settles at 1050 and then gets " stuck "at 1500 again after some time?

Once the high idle issue appeared, the bike would high idle cold then drop to 1050 when fully warm...normal like (on mine it looked to be right at 1000). Then after a few more miles, it would high idle at 1500 and sometimes spike to 1700. The high idle would continue until shutdown.

The low idle issue (drop to 500, then slow rise to 750-ish) would only happen after bike had been ridden 30+ minutes, often not till it had been ridden a full hour.

Upon any start-up with engine cold the idle would return to normal pattern: high idle at 1500 then down to 1050, after which it was only a matter of time before one or the other would return. After cleaning the TPS, both issues went away for 7-8 rides lasting from 30 minutes to 1.5 hours with two exceptions when idle dipped to 900 momentarily.

I traded it in at this point.
I didn’t ride today (monsoon going across Florida all day) but just started it and, cold, it went straight to 1300-1400, not quite 1500. Tomorrow it’s gonna get an I-95 injector cleaning. Will report back.
Thank you pdedse for the summary.
Nemo, cold it should go to 13-1400. That would be normal cold idle speed. Did you let it run until warm at which point it's supposed to drop to 1050?