NO ECU Available already!

Pete in PA

Running like a top
Thread starter
I'm literally going to buy a new to me 2014 CB1100 Oct. 1st and now having serious 2nd thoughts.
The ECU is already not available and there is exactly 1 used on EBAY.
With the potential idle problem and just the potential for the ECU going bad and bricking the whole bike, I don't know If I want to go through with the buy.

Am I being over cautious?
 
I'm literally going to buy a new to me 2014 CB1100 Oct. 1st and now having serious 2nd thoughts.
The ECU is already not available and there is exactly 1 used on EBAY.
With the potential idle problem and just the potential for the ECU going bad and bricking the whole bike, I don't know If I want to go through with the buy.

Am I being over cautious?

RE: "Am I being over cautious?"

Tough for anyone to say, but... probably? Back when this happened to my 2014 Standard, it didn't help me feel one iota better knowing that there weren't that many affected bikes. I remember wondering "ok, not a lot of bikes are affected 2-3 years after purchasing, but what about 10+ years later?" Would whatever was causing the high/low idle strike other owners' bikes later on? It seems to me that this has not been happening, that the issue begins let's say 10k miles are sooner, or within the first 1-3 years, but I'm going on memory here when I would read of others' stories of when the issue started for them.

Pete, are you aware of the different ECU part numbers for the 2013/2014 CB1100 models and the 2017ex? Some have surmised that this is because Honda knows of the possibility of pre-'17 ECU failure, and that the newer ECU had "the fix", whatever that might have been.

Have you checked the ECU part number (and availability) for the 2017 EX model? I'm pretty sure some '14 owners used the different '17 ECU with success. Someone please correct me if I'm wrong.

But that new part number for the '17 raises the question: instead of a '13/'14 model, could you be happy with a '17EX, or are you set on a the '14? As far as we know, there have been no '17ex models with high/low idle.

If the '17 is not of interest, and neither the '17 ECU nor other can be obtained and the issue would bug you if you bought the '14 you have in mind...maybe pass altogether and look at another air cooled, classic-style bike...like the Kawasaki W800! I've owned 2 of them; enjoyed them lots--so much I sold them for other bikes, but if anything happened to my '17ex, I'd replace with a W800.
 
I'm literally going to buy a new to me 2014 CB1100 Oct. 1st and now having serious 2nd thoughts.
The ECU is already not available and there is exactly 1 used on EBAY.
With the potential idle problem and just the potential for the ECU going bad and bricking the whole bike, I don't know If I want to go through with the buy.

Am I being over cautious?
You are not being overly cautious. With so many other really good motorcycles to choose from why take the risk? I dealt with the idle issue, and I hated every minute of it. When your bike is either stalling unexpectedly, or revving unexpectedly to 1,500 RPM all the time, you will not enjoy riding it. Even if the chance of this happening to an older bike is probably slim to none, if it did happen, and you have no way of fixing it, you'll be sorry you made the purchase. And I speak as a person who absolutely loves my 2014 CB1100 Dlx.
 
My 2013 standard had under 3,000 miles on it when I bought it in about 2019. I can't recall exactly when I bought it or how many miles it had on it when it started having the problem, but it wasn't much over 3,000, if that. I bought a new ECU from Partzilla for approximately $500 US. The bike then worked as it should.
I would not use a used ECU. The replacement had a different part number, but was listed as the correct part and worked perfectly. The idle problem makes the motorcycle not only difficult and frustrating to ride, but very dangerous.
 
You are not being overly cautious. With so many other really good motorcycles to choose from why take the risk? I dealt with the idle issue, and I hated every minute of it. ...

I'll change my "probably" to what Dave says. I think I wrote the other day...personally, I wouldn't buy a '13 or '14 because of jaded experience. There are so many happy owners with '13/'14 models. But I simply wouldn't want to risk repeating the experience. Every bike will have issues, but if parts are not available, that raises the bar of what I'd be willing to risk.
 
Am I being over cautious?
If it were me, I wouldn't turn the deal off. You've done your research so you know what to look for. Look over the bike fully and see that it starts, idles, warms up, and rides normally. Good idle cold and warm. To me that's the right level of caution.

If all seems right, you'll probably be fine. The risk isn't zero, but your chance of success will be as good as anyone. I bought my 2014 last year and it has been a blast. I hate to think that I might have missed out for fear of this problem. It could still happen to me I suppose, but I don't give it any thought and if it happens I'll just deal with it then.

I'm not trying to minimize your concern. Just saying that if I was able to start it, observe it, and ride it before purchase, that would be enough due diligence for me.
 
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I'll try to answer all. I have no interest in a streetbike with spokes, so no 2017.
I seriously doubt a different year ECU will work or it would be listed in the parts look up, that's just how they work.
If I don't get a 14 CB11 I'll just keep my 750 Nighthawk.
I'll just be very tuned in on my test drive and go from there.

Price on an ECU from Japan?
 
Something to consider is the availability of parts in general for the bike. It’s a rarity compared to a lot of other bikes and things like body and trim will start becoming harder as well.

Of course with a Nighthawk, you’re already used to this.
 
Thread starter
Something to consider is the availability of parts in general for the bike. It’s a rarity compared to a lot of other bikes and things like body and trim will start becoming harder as well.

Of course with a Nighthawk, you’re already used to this.
I'm amazed what IS still available for the CB11, the tank for one.
 
Edit: I learned from much more experienced members (@Cormanus, @Dave) that I only had partially correct informationin my original post below: A43 only applies to the black 2014 CB1100s. The red 2014 Deluxes have part numbers 38770-MGC-A73 and 38770-MGC-A74, with "4" in A74 being the newest version for the Deluxes (wanted to get this out there to keep anyone making an expensive mistake just as I would have with the help of you all). The A74 versions do also appear in stock at Webike as of this moment.

(To find Dave's original post, search on the part numbers above.)

==== My Original Post ====

The correct part number for the corrected ECU is 38770-MGC-A43. The "3" in "A43" at the end of the part number is the key differentiator between a replacement ECU you want and one you don't.

Screenshot_20260922-165525.webp

My understanding is that the "3" ECU corrects the iidle problem.

Anyone who knows this to be absolutely correct, please confirm? Otherwise I'll do more research.

As far as a general CB1100 parts shortage in the future, my experience sourcing GB500 parts (also very rare bikes) encourages my belief that pristine used CB1100 parts will become more and more available as the years pass and various mishaps result in a growing supply of parted-out CB1100s.
 
Last edited:
Thread starter
The correct part number for the corrected ECU is 38770-MGC-A43. The "3" in "A43" at the end of the part number is the key differentiator between a replacement ECU you want and one you don't.

View attachment 4394

My understanding is that this ECU corrects the iidle problem.

Anyone who knows this to be absolutely correct, please confirm? Otherwise I'll do more research.

As far as a general CB1100 parts shortage in the future, my experience sourcing GB500 parts (also very rare bikes) encourages my belief that pristine used CB1100 parts will become more and more available as the years pass and various mishaps result in a growing supply of parted-out CB1100s.
A pretty penny, but if it fixes the bike IF I have a problem.👍 Good to know there are options.
 
Gentlemen: I've been doing some research on ECM part numbers and discovered that not only has the ECM part number been superseded, but different Honda CB1100 models used different part numbers for the same year.

I believe the reason for the different ECM part numbers used for the same year is because the Standard (single pipe) and the Deluxe (two pipe) models required different parts. Can someone please explain why this is so? Partzilla identifies the different models using a model designation: CB1100SA AC (Deluxe?) versus CB1100AC (Standard?). Chaparral Motorsports uses VIN numbers to differentiate between the two models.

Chaparral identifies the old, and superseded part numbers for year 2014:
VIN JH2SC658-EK000001: OLD 38770-MGC-A73 NEW 38770-MGC-A74
VIN JH2SC651-EK100001: OLD 38770-MGC-A42 NEW 38770-MGC-A43

I just visited the Partzilla website, and for the 2014 model they do NOT list a superseded part number. I assume that if you place your order with Partzilla for the old part number they will automatically update it with the superseded part number.
CB1100SA-AC: 38770-MGC-A73
CB1100 AC: 38770-MGC-A42

I also discovered on the Partzilla website that the ECM part number for the year 2017 model(s) CB1100CA AC - CB100CA is: 38770-MGC-A41.

I apologize if this information has been shared previously, but as I was reading through the most recent posts I became confused with the part numbers identified, and had to verify for myself. Your comments and clarifications are most welcome.
See this post of Dave's from the big thread on the idle speed instability.
 
Thread starter
RE: "Am I being over cautious?"

Tough for anyone to say, but... probably? Back when this happened to my 2014 Standard, it didn't help me feel one iota better knowing that there weren't that many affected bikes. I remember wondering "ok, not a lot of bikes are affected 2-3 years after purchasing, but what about 10+ years later?" Would whatever was causing the high/low idle strike other owners' bikes later on? It seems to me that this has not been happening, that the issue begins let's say 10k miles are sooner, or within the first 1-3 years, but I'm going on memory here when I would read of others' stories of when the issue started for them.

Pete, are you aware of the different ECU part numbers for the 2013/2014 CB1100 models and the 2017ex? Some have surmised that this is because Honda knows of the possibility of pre-'17 ECU failure, and that the newer ECU had "the fix", whatever that might have been.

Have you checked the ECU part number (and availability) for the 2017 EX model? I'm pretty sure some '14 owners used the different '17 ECU with success. Someone please correct me if I'm wrong.

But that new part number for the '17 raises the question: instead of a '13/'14 model, could you be happy with a '17EX, or are you set on a the '14? As far as we know, there have been no '17ex models with high/low idle.

If the '17 is not of interest, and neither the '17 ECU nor other can be obtained and the issue would bug you if you bought the '14 you have in mind...maybe pass altogether and look at another air cooled, classic-style bike...like the Kawasaki W800! I've owned 2 of them; enjoyed them lots--so much I sold them for other bikes, but if anything happened to my '17ex, I'd replace with a W800.
The bike I'm looking at only has 3500 miles on it.
Still makes me wonder what it really is. Time or miles?
I still think it's a mechanical problem, vacuum leak, or carbon buildup.
 
Gonna sound real ignorant here due to my prolonged absence and intermittent presence on this forum over the years, but, what in the world is this faulty ECU/idling problem being mentioned here?

Are there any good dedicated threads documenting said issue/symptoms?

Is it a hardware gone bad situation or something that could potentially be fixed by way of reprogramming the ECU?

Apologies if threadjacking- just don't recall ever hearing of this outside of a few early Guhl tuned idling issues..

TIA
 
Gonna sound real ignorant here due to my prolonged absence and intermittent presence on this forum over the years, but, what in the world is this faulty ECU/idling problem being mentioned here?

Are there any good dedicated threads documenting said issue/symptoms?

Is it a hardware gone bad situation or something that could potentially be fixed by way of reprogramming the ECU?

Apologies if threadjacking- just don't recall ever hearing of this outside of a few early Guhl tuned idling issues..

TIA
Here's a couple threads:



Those may be enough info, but if not try searching "idle" on the forum
 
@E11even_Hunnit, the problem referred to is one experienced by a relatively small group of forum members where the idle speed of the bike rose and there didn't seem to be anything that fixed it. Some members had success replacing the IACV; others didn't; others in Europe reported that their dealers had patched the ECU and fixed the problem. Honda America refused to acknowledge there was a problem, but @Nachodaddy reported replacing the ECU on his bike fixed the problem. Then Dave noted the different part numbers.

Wade your way through the CB1100 High idle instability thread.
 
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