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This idling issue was already widely discussed on the previous CB forum.
There were a few remedies as mentioned above but ultimately the newest ECU version finally solved the idle problem for good.
"Drop a gear and disappear"®
'24 Kawi Z650RS - Hooligan®
'14 CB1100 DLX, s/n 170, 42K kms - FOX®
'14 CB1100/ABS, 134K kms - sold
'13 CB1100/c-ABS - 56K kms - sold
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(03-28-2026, 03:31 PM)dave Wrote: Gentlemen,
Since this thread talked a lot about replacing the ECU, I had to ask this question:
I plan to never sell my CB1100. What happens in 10 years from now, when my bike is 26 years old, and my ECU, or another electronic component required to make the bike run, fails? There would be zero chance of getting a replacement ECU from Honda, and I don't believe any aftermarket companies manufacture any. So is searching the junkyards for a used part my only option? I would be inclined to purchase a new ECU and install it to be sure it functions, then run with it or the old.
Not checking this forum often, has anyone replaced the ECU and not solved the idle issue?
In November 2017, I was so very fortunate to purchase a new, still in the crate 2014 CB1100 for $7,249.99 + my 2018 XT250 trade-in. I wish there was one still available!
24 Yam XVS950 23 MG V7-850 23 Yam XT250
18 XVS950 22 Bonneville 20 CanAm Ryker
14 Honda CB1100 18 Yam XT250 16 MG V7II
17 Yam TW200 12 Bonneville 02 Sportster 1200S
03 Sportster 883 76 Honda CB750F 75 Honda CB360
70 Yam CT1 72 Yam CT2 72 Yam AT2 70 Honda SL350
70 Honda CL350 67 Honda CL160
67 Honda CB16062 Honda CA110
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This thread is only a couple months old. I've tried without success to locate the superseded ECU for my 2014 Standard.
Partzilla and everywhere else I look, list it, A43, as unavailable.
Ebay shows one, but I don't trust it's legit. Anyone have another source to check?
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List the needed OEM P/N to avoid costly mistakes..
"Drop a gear and disappear"®
'24 Kawi Z650RS - Hooligan®
'14 CB1100 DLX, s/n 170, 42K kms - FOX®
'14 CB1100/ABS, 134K kms - sold
'13 CB1100/c-ABS - 56K kms - sold
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05-10-2026, 05:31 AM
(This post was last modified: 05-10-2026, 05:31 AM by 1973cb750.)
Yes i just looked at the usual spots says un available wth
38770-MGC-A43
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05-10-2026, 08:34 AM
(This post was last modified: 05-10-2026, 08:37 AM by Jd2ride.)
That's the same thing I found. Either someone bought all remaining stock up or Honda decided to delete the part for some unknown reason.
Weird for it to vanish like that, either way.
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Peter is right. Posting the part number you are searching for is the best way to enable the Forum Members to assist.
If 38770MGCA42 is the correct module, Webike has a brand new unit in stock:
https://japan.webike.net/products/26246696.html
I have purchased many parts directly from them. For my transactions, they have been incredibly reliable. Customer Service was also strong assisting me with part selection. The shipping costs are high because of the international shipping. Occasionally, I have had to pay tariffs on parts which have a high steel content. Hope this helps. David
2017 Honda CB1100 EX
The most sophisticated, smooth, perfectly engineered motorcycle I've ever owned. A pleasure in every way.
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05-10-2026, 09:30 AM
(This post was last modified: 05-10-2026, 09:34 AM by LucienLeFranc.)
I would be fairly confident the used ECU currently offered on eBay is legit, as the seller is listing many other CB1100 parts, most certainly from a salvaged bike, and--further--eBay makes it easy to get a refund on a faulty part, so someone could buy it, test it in their bike, and get a refund if it isn't a good part.
I also feel that, as the years pass, more and more perfectly good ECUs will appear on eBay as, sadly, CB1100s end up in salvage yards.
Anyone who is particularly worried about this issue might proactively buy a new or used backup ECU now, but for me myself, given my experience with salvage-parts availability for other old rare bikes, I feel pretty confident that I'll find a perfectly good salvaged ECU if ever I need one.
(My urgency toward acquiring a backup will increase, however, if at some future time I start seeing reports of numerous failing ECUs, so that demand could possibly outpace the supply from salvaged CB1100s.)
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Motoloves of my life:
2014 CB1100 DX
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I think the correct, supersede P/N is 38770-MGC-A43 ?
"Drop a gear and disappear"®
'24 Kawi Z650RS - Hooligan®
'14 CB1100 DLX, s/n 170, 42K kms - FOX®
'14 CB1100/ABS, 134K kms - sold
'13 CB1100/c-ABS - 56K kms - sold
*Grand Chancellor*
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Yes the 14 is a a43 and the 13’ is a a24
Old is 14 a42. Old 13 is a a23
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