CB1100 Idle speed instability problem

[Enzofour_imp]

Yesterday after 1 hour on the road it turned off, it no longer held the minimum.
She turned off and on again, by turning the key, and left again normally.
After another hour of travel it is off, I repeat the procedure of turning it off and on with the key and it takes me home without any problem, 20 minutes of road practically in first and second gear due to traffic.
When I get home, I leave it on for a while and accelerate, nothing happens, at least very regular.
Who can tell me if the new IACV cod. Can 16431-MGZ-D01 fitted on 2017 and later models be used on pre 2017 models? Honda cod. 16430-MFJ-D01

[Enzofour_imp]

Yesterday after 1 hour on the road it turned off, it no longer held the minimum.
She turned off and on again, by turning the key, and left again normally.
After another hour of travel it is off, I repeat the procedure of turning it off and on with the key and it takes me home without any problem, 20 minutes of road practically in first and second gear due to traffic.
When I get home, I leave it on for a while and accelerate, nothing happens, at least very regular.
Who can tell me if the new IACV cod. Can 16431-MGZ-D01 fitted on 2017 and later models be used on pre 2017 models? Honda cod. 16430-MFJ-D01

Note: the temperature was only 22°

[max]

Whilst i was reading the german forum's post on the 256000 km cb1100 i came across this description, i will post the german and translated version and put it out here for your perusal, the owner had an issue with the iacv and repaired it by cleaning the worm shaft on the iacv, he claims it has not re-occurred since;

ich war damals bei meinem Hondahändler. Anfang haben die mir nicht geglaubt, da der Fahler nicht stabil reproduzierbar war und in sehr unterschiedlichen Situationen auftrat. Ich habe meine CB dann dem Meister für zwei Tage überlassen und er ist damit dann seinen Arbeitsweg gefahren – und hat dieselben Probleme wie ich. Der anfängliche Verdacht auf defekte Benzinpumpe konnte durch einen provisorischen Austausch auf Garantie ausgeschlossen werden.

Die Ursache war die verschmutze Schnecke beim Leerlaufsteller und deshalb wurde die Leerlaufsteuerung nicht friktionsfrei umsetzt. Nach der Reinigung waren die Probleme bei meiner CB weg und sind auch nie wieder aufgetreten.

Ich weiß aber auch von einem anderen CB-Fahrer, dass ein Software-Update 2017 sein Leerlaufproblem gelöst hat.

Viele Grüße

Thorsten


I was at my Honda dealer at the time. At the beginning they didn't believe me, because the error was not stable and reproducible and occurred in very different situations. I then left my CB to the foreman for two days and he went to work with it - and has the same problems as me. The initial suspicion of a defective fuel pump could be ruled out by a provisional exchange on guarantee.
The cause was the dirty worm on the idle actuator and therefore the idle control was not implemented without friction. After cleaning, the problems with my CB were gone and never came back.

The writer also claims that a 2017 cb was repaired with a software update, just like wisedrum's one.

And a link to the page in question, it is quite a way down and of course in german;
http://motorrad-und-touren.de/motorraede...cb-1100-ex
( Link opens in a new tab )

Just wondering if the same can be done by removing one of the rubber hoses on the top of the iacv housing and squirting some brake cleaner into the alu pipe whilst operating the red engine stop switch to motivate the iacv back and forth.



Just for your information.

[the Ferret]

Interesting. Is this worm gear is the stream of gas, in other words, would a dash of Seafoam now and then help to keep it clean and lubricated?

[DSD_imp]

I have a 2013 and fortunately have had no idle issues with mine. I have read every post and have followed this thread with great interest. I am not a mechanic or technician. This is just a thought. Could the IACV be converted cheaply to a manual operation? Like a choke in the old days.

[max]

Hi Ferret and sorry for the expanded picture everyone,

I read your reply as; " in the stream of gas " in other words fuel/air mixture, ie selfcleaning.
Ahhm no, the iacv regulates the bypass air ( bypasses the butterfly valves in the picture ) in a measured amount depending on engine temperature.

The filtered air is let in at two openings just below the iacv in the throttle body and leaves the iacv by means of the two hoses on top ( left hand side )
and two air passages inside the throttle body ( right hand side ) after it has been regulated by the iacv piston on it's stainless worm shaft.
It gets passed ( sucked ) forward of the butterfly valves by the "vacuum" created by the engine in each cylinder in turn where
the injectors "mist" the fuel in the intake at which point it cleans all parts ( valves ) and the cylinder wall if it is not ignited by the sparkplug .

Here is a short clip removing the iacv, not possible in our case with the engine in place,
showing the air passages;
https://www.youtube.com/watch?v=_asKPXxuHbQ

In carburettor days this idle speed was achieved by slightly opening the carburettor slide and
dribbling some fuel through the small "idle jet" and the "idle air/fuel mixture screw" keeping the engine running at idle.

The previous post is just an idea that could be tried with the engine not running instead of replacing the iacv,
maybe it works maybe it doesn't.

And in reply to DSD; i have driven with the iacv disconnected but it is not reliable in the long run
and i think the air/fuel mixture may not be optimal for the purpose, however
i think iamhero has used this idea temporarily with some success before he replaced his iacv and cured the issue permanently.

[the Ferret]

So in other words it only deals with air and not with fuel

[max]

correct.

[Lord Popgun]

Interesting info Max. The brake cleaner spray idea would sure be something to try before changing out an IACV.

[SportsterDoc]

Binding has long been a concern but the suspicion was of the piston binding rather than the screwdrive. Lubrication may have mitigated either binding.

http://cb1100forum.com/forum/showthread....#pid264896