CB1100 Idle speed instability problem

[max]

Very good observation Jeff, as you can see we are still lost as to why this happens on these 2014 models ( mostly ).
Anything you can find out with regards to hot/cold etc. would help focus our attention to what the software is doing in this case.
Yourself and Dave can bounce things around, in the meantime for your info there is a switch on the clutch handle and it's main function is to enable the engine to start with the clutch dis-engaged ( pulled in ) whilst in gear but you have probably worked that out by now ( and so has the e.c.u. engine controller with it's flukey software )
Thanks for your input .

[jeffmazz_imp]

I was finally able to get the bike out today and it did the famous idle instability thing after it got warmed up enough. Dave asked what the idle does when I go to neutral and disengage the clutch. The idle stabilizes just as it does when I fully compress the clutch lever to the bar. I have only experienced the high idle (1,600 RPM) once when the bike had under 1,000 miles. It was a very hot day and it hasn't done it since. I've never had the bike stall during it's idle fit but it does vary quite a bit (500 - 600 rpm's) when it starts acting up. It is weird that fully compressing the clutch or going to neutral calms it down.

[tod.branko_imp]

I was finally able to get the bike out today and it did the famous idle instability thing after it got warmed up enough. Dave asked what the idle does when I go to neutral and disengage the clutch. The idle stabilizes just as it does when I fully compress the clutch lever to the bar. I have only experienced the high idle (1,600 RPM) once when the bike had under 1,000 miles. It was a very hot day and it hasn't done it since. I've never had the bike stall during it's idle fit but it does vary quite a bit (500 - 600 rpm's) when it starts acting up. It is weird that fully compressing the clutch or going to neutral calms it down.

Have you had your clutch serviced? Warped plates, faulty springs? Does your rear wheel creep on the center stand in neutral?

'14 CB1100 STD 5 speed

[jeffmazz_imp]

I was finally able to get the bike out today and it did the famous idle instability thing after it got warmed up enough. Dave asked what the idle does when I go to neutral and disengage the clutch. The idle stabilizes just as it does when I fully compress the clutch lever to the bar. I have only experienced the high idle (1,600 RPM) once when the bike had under 1,000 miles. It was a very hot day and it hasn't done it since. I've never had the bike stall during it's idle fit but it does vary quite a bit (500 - 600 rpm's) when it starts acting up. It is weird that fully compressing the clutch or going to neutral calms it down.

Have you had your clutch serviced? Warped plates, faulty springs? Does your rear wheel creep on the center stand in neutral?

'14 CB1100 STD 5 speed

Have you had your clutch serviced? Warped plates, faulty springs? Does your rear wheel creep on the center stand in neutral?

'14 CB1100 STD 5 speed
Clutch is fine. When sitting in gear with the clutch disengaged with my two fingers the clutch lever will move out approx. 1/2" before engaging so it is completely disengaging.

[syncronizator_imp]

Just for reporting purpse.
Idle problem seems to be solved until now. I have traveled 28tkm since replacing the IACV. The problem never recurred. Now my CB1100 has 58tkm on clock.

[max]

That's the kind of news we like, thanks for the update.

[the Ferret]

Good deal sync

[Nachodaddy]

Here we go again.
I bought my 2013 standard in August, 2021 with around 4500 miles on it. A very clean bike that looked well cared for. I don't ride much, but recently the idle will suddenly drop to around 500 RPM and the engine will die. This first happened when I was riding very slowly, using the clutch to regulate my speed while practicing very slow speed turns, figure-eights and U-turns in an empty parking lot. Then it happened after riding fairly fast and stopping at a traffic light. Clutch pulled in, bike in 1st gear, engine idles down to 500 for a second or so and dies. This happened a few more times on the way home. The bike is hard to start when this happens. Enough so, that other traffic is getting irritated with me and I have no place to move the bike, but have to keep trying.
I will take it out and see if a few things help, like putting it in neutral and leaving the clutch out when I start it, turning off and on the master switch before starting it after it dies, and rotating the throttle completely each time.
I think it is too old for Honda to give me any kind of warranty coverage and I have absolutely no confidence in any of the local "Honda" shops.
Weather at this time is very mild - sixties to mid-seventies (F) dry air, typical desert winter weather. I very much appreciate all the posts, attachments and pictures others have posted of their experiences with this problem. If I had been smart enough to read this forum before buying this bike, I would not have bought it, especially at the price I paid.

[max]

Would think we are all sorry to hear this bad news Nacho, as for research you would have read that the majority of cases by far is on the 2014 models with very few exceptions.
So you could have drawn the conclusion we all have that the rest of the years are unaffected and safe to buy.
We only know this from experience and although i stated that the permanent magnets in some parts seem to be affected ( by lack of other evidence ) that is just my opinion and i would like to point out that a software update has also been known to repair this issue permanently with the same affected iacv in place as reported by several members in different countries.
On the other hand this is actually the only ( but unfortunate ) fault typical for this bike which is not a bad score overall.

On a happier note; where would you be without the assistance of the forum by Guth and co ( thanks gents! ).....

Yes it would be interesting to have more tests like you want to do, who knows what we might find, thanks for posting.

[Cormanus]

Nachodaddy, that’s a bummer for you. I can’t recall another 2013 reporting this problem and, even amongst the 2014 bikes, it’s rare. I hope you’re able to add to what we know about this issue. Otherwise, replace the IACV and it should be fine.