CB1100 Idle speed instability problem

[peterbaron]

Very valuable info Enzo

[dave]

Today the Honda dealer informed me that in 2016 Honda sent dealers an ECU update.
This update was not an official reminder, but a tip to use on 2014/2015 models with low idle and shutdown issues.
On 14/04/2021 they will install this update for me, we will see the effects.
I will try to get the name / code of the firmware for this update.
Meanwhile, with the replacement of the IACV the bike didn't give me any more problems.

I contacted Honda of America and they informed me that any ECU updates were not authorized for the North American market.

[Houtman_imp]

Thanks Enzo for that useful info , so I never had a problem but you never know.

[GoldOxide_imp]

I wonder if that would fix the very low idle on the 2014 model after a long, hot day freeway cruise at the first stop. Never stalled (obviously I did not want it too), but it tried and it eventually recovered to normal.

[PowerDubs_imp]

Today the Honda dealer informed me that in 2016 Honda sent dealers an ECU update.
This update was not an official reminder, but a tip to use on 2014/2015 models with low idle and shutdown issues.
On 14/04/2021 they will install this update for me, we will see the effects.
I will try to get the name / code of the firmware for this update.
Meanwhile, with the replacement of the IACV the bike didn't give me any more problems.

I contacted Honda of America and they informed me that any ECU updates were not authorized for the North American market.

Wouldn't stop Don Guhl from copying that file and using it as the base for his tunes.

[jeffmazz_imp]

I haven't had major idle instability issues (stalling, very high idle) but my bike (2014 Standard) will idle up and down from about 800 RPM and 1,200 RPMs after riding for a few miles on a hot day. I'm a two finger clutch guy so when I stop my clutch lever isn't fully compressed to the bar. Yesterday the goofy idle was doing it's thing and I put all fingers on the clutch lever and pulled the lever all the way to the bar......the idle stabilized immediately. I continued the rest of the 2 hour ride alternating between two finger clutching and four finger clutching. The idle is normal with the clutch lever fully compressed to the bar every time. This isn't making sense to me. Any thoughts?

On another note, I noticed that Don Guhl is no longer flashing ECU's for street bikes. I visited his website and it specifically says not to send any ECU's in for re-flashing as they will be returned without any service being performed. I was going to call to see what this is all about. I'm wondering if you simply have to tell them it is for "off road use only" and you're good to go.

[Lord Popgun]

Probable the EPA cracking down. Harley got whacked with $12 million penalty for their “off-road” parts. I think tuners are in the sights now. I’ve seen discussion about this on other sites too.

[GoldOxide_imp]

I recall a few times off-ramping from a freeway after a long, profuse hot, humid day of riding and coming to the stop light with the idle RPM high (no throttle input). After less than 15 seconds it would settle down to normal idle. The offramp length would be between 500 and 1000 meters and mostly all casual deceleration.

Uncommon and unpredictable when it would happen, except it appeared only on very hot days.

(2014 CB1100)

[dave]

I continued the rest of the 2 hour ride alternating between two finger clutching and four finger clutching. The idle is normal with the clutch lever fully compressed to the bar every time. This isn't making sense to me. Any thoughts?

Hi jeffmazz. What does the ide speed do when the engine is in neutral with the clutch disengaged? When my high/low idle condition was occurring on my bike I never checked to see if clutch engagement had any affect. The difference in RPM that you described is exactly how my bike idle issue started. It would come and go randomly, and it eventually got worse to the point where it would stall, of idle as high as 1,600 RPM.

[jeffmazz_imp]

I continued the rest of the 2 hour ride alternating between two finger clutching and four finger clutching. The idle is normal with the clutch lever fully compressed to the bar every time. This isn't making sense to me. Any thoughts?

Hi jeffmazz. What does the ide speed do when the engine is in neutral with the clutch disengaged? When my high/low idle condition was occurring on my bike I never checked to see if clutch engagement had any affect. The difference in RPM that you described is exactly how my bike idle issue started. It would come and go randomly, and it eventually got worse to the point where it would stall, of idle as high as 1,600 RPM.

Dave,
I haven't tried putting it in neutral and disengaging the clutch. I'll try it next time I go out and report back.