CB1100 Idle speed instability problem

Magnus_imp said:
So I have the 1500rpm idle problem and I've replaced the Idle Air Control Valve (IACV) and now the engine oil temperature sensor (EOT?) as well. I also did the throttle position reset thing where you open and close the throttle a few times with the key on. So far no real change.

The bike will actually idle perfectly for a few minutes once it gets up to temperature. But then after a few more minutes of riding it goes back up to 1500rpm idle and stays there. I can't seem to figure it out. I wish I had an oil temp gauge so I could see if it's oil temperature related. Do these bikes have a thermostat for the oil cooler or anything? I wonder if the motor is getting too cold or (less likely) hot?
Hi Magnus. I am in San Diego also, with the same problems. I replaced my EOT sensor with no luck also. However, when I unplugged the EOT sensor the bike ran perfectly - maybe you can try this?

If you saw my earlier post, my WFO run "seems" to have fixed my bike. I have taken the bike on several short (less than 60 mile round trip) runs and ridden it around town and it has been running the best it ever ran. Don't ask me to explain how or why, because I don't understand what could have changed. But, try disconnecting your EOT sensor (when the engine is off) and see what happens.
 
To answer the upcoming question, does the CB have a temperature related sensor in the oil cooler, my mechanic explained it that way, there' is valve which the cold oil is not able to pass to flow into the cooler. When it is warmed up to a certain degree, it only then can do so, 'cause the oil molecules have changed their diameters, somehow mutated. This creates the flow and its cooling down.

My CB sometimes idles high with a warm engine, not always. I still don't understand it.
But it has good emission values when it was checked by the TÜV a few days ago, so I don't care about it that much anymore and furthermore will wait for its fully selfhealing. Hope is the last to die......:angel: I will not spend money on expensive parts with questionable interventions and results.

Wisedrum
 
The output of the oil cooler goes to the spark plug area and then back to the sump. The EOT sensor is in the return line from the head to the sump.

The output of the oil pump has two paths. One to the oil filter and out to the engine, transmission and all, and one to the oil cooler. The oil filter line has a relief valve called Pressure Relief Valve.

The oil from the pump TO the cooler does pass through a Relief valve (located in the pump and called Relief Valve).

On the oil schematic in the service manual in section 4, the valve is drawn such that it doesn't meter oil, just dumps it if there is over pressure. But, there is no explanation and no specs listed. It is a serviceable item though. Edit to add. I don't think it would make sense to limit flow to the cooler as the spark plug area is going to get hot fast, and that is not a good thing, thus the oil cooling there.

There are no temperature valves in the oil system shown anywhere or mentioned in the servicing procedures. Only the EOT sensor. I think your mechanic is blowing smoke. Or just figuring it works that way because some other bike does.
 
My mechanic just compared it with systems he knows. He didn't worked for Honda motorbikes, although he has some.

Which ever will be the oil cooler system of the CB, as long as it works, I don't worry about it. But thanks for your detailed information.

Wisedrum
 
Wisedrum, If you PM me your email address, I will send you a scan of the oil schematic. I won't post it as it is copyright...
 
I think popgun is correct. As I recall, the CB1100 engineers had a real problem with high heat around the spark plugs so it makes sense to have unregulated oil flow from the oil cooler to the channels around the spark plugs.
 
So I did the riding WFO for a while a couple of days, and it seems to have somehow helped with the low-high idling problem (or it might be a coincidence, who knows at this point). Since I've been putting 91 octane gas from day one (thinking it was better), and that might have actually been a part of the problem, I'm moving to lower octane gas from now on.

I'm also taking the bike for service this weekend, so I'll mention the problem and all this discussion to the Honda mechanic. However, I have little to no hope on this. This is sad and disappointing from such a big brand, but based on others experience they seem to be clueless to say the least.

I'll keep you guys posted if something interesting comes up soon. For now, I'll keep doing the WFO therapy from time to time and crossing fingers when we hit 80 degrees in LA. Forecast says that will happen this weekend, so if the issue has to come back, no doubt it will be by then, when bikinis are seen around the coast.
 
I took my EX in for it's first annual service today. I had pre warned the dealership about this issue, which I myself have not experienced, and gave them the details of the re-map that Beardy put up. They were very onboard when I got there, had spoken with Honda UK, and had the new software available. However Honda strongly advised to only re-map if the issue is apparent, otherwise leave well alone as it could itself cause other problems and is non reversible. So mine was left as is, but at least I know it's available if needed.
The service manager talked through a number of other possible causes, including riding style. He suggested that the notion of a throttle WFO ride could indeed have some value, making sure the engine is at operating temperature first. Buying a second hand machine and having a different style of ride/throttle use from the previous owner is he said a known phenomena with modern ECU's that can 'learn' a riders ways.
He was just throwing his experience into the pot I guess.
 
riding style, Lol

anyway, be sure to show him my video of the issue (thats resolved by simply changing the whole throttle body, under warranty)




there is nothing more clear to show an issue like a good video
images say more than words
 
Riko_imp said:
riding style, Lol

anyway, be sure to show him my video of the issue (thats resolved by simply changing the whole throttle body, under warranty)




there is nothing more clear to show an issue like a good video
images say more than words
I think he was referring to throttle use.
 
JustCruising_imp said:
Riko_imp said:
riding style, Lol

anyway, be sure to show him my video of the issue (thats resolved by simply changing the whole throttle body, under warranty)




there is nothing more clear to show an issue like a good video
images say more than words
I think he was referring to throttle use.
I think he was referring to throttle use.
I know

but even the slightest hint of tought of linking riding style as a possible cause of the throttle issue is absurd

all this evolution in automotive and electronical technology such as Fuel Injection, makes his conclusion a joke tbh, especially when you think about it

sounds like a desperate mechanic to me
 
I don't know Riko... even in the old days if you bought a car from an "old" person who had driven it like the proverbial old lady going to church, you had to blow them out before they would run right. I remember my older brother in the 50's pouring water down the carb of a running car while holding the throttle open and all manner of crud billowing out the tailpipe.It may have been wive's tale that it did something, but guys of that era swore by it.

The car mfgs today will tell you a car learns your driving habits and responds accordingly. Don't see why a motorcycle wouldn't. Computers are computers.
 
I can remember my older brothers using a gas additive to clean carbon out their car motors. My older brother used in on the street where we lived and took he** from everyone for the smoke it produced. The other brother took out to a quiet road before adding it. Sometimes being first to try something is not always best.
 
Riko_imp said:
JustCruising_imp said:
Riko_imp said:
riding style, Lol

anyway, be sure to show him my video of the issue (thats resolved by simply changing the whole throttle body, under warranty)




there is nothing more clear to show an issue like a good video
images say more than words
I think he was referring to throttle use.
I think he was referring to throttle use.
I know

but even the slightest hint of tought of linking riding style as a possible cause of the throttle issue is absurd

all this evolution in automotive and electronical technology such as Fuel Injection, makes his conclusion a joke tbh, especially when you think about it

sounds like a desperate mechanic to me
I think he was referring to throttle use.
I know

but even the slightest hint of tought of linking riding style as a possible cause of the throttle issue is absurd

all this evolution in automotive and electronical technology such as Fuel Injection, makes his conclusion a joke tbh, especially when you think about it

sounds like a desperate mechanic to me
Well I guess you'd better just go sort it yourself then.

There's always those that know best. I was just passing on his comments, and what Ferret says above is in fact just what this guy said to me re the machine 'learning' it's operator. Change the operator and there may be problems. He went on to say that the bike manufacturers are quite open about their fuel injection systems being technically behind those of the car industry.
He was just talking, thinking out aloud and calmly throwing out ideas and possible causes, certainly nothing desperate about him and he certainly wasn't desperately trying to skirt the issue.
 
After 25,000 trouble-free miles, my 2013 exhibited the very annoying high idle problem for four months (and over 3000 miles) following a single afternoon of the stalling similar to Riko's posted video. So annoying.

During a full track day at Laguna Seca, flogging it for 160 miles and however many laps that is, the high idle problem disappeared. That was November 13. So far, 5 months and about 5K more miles it hasn't returned. Please note: I'm only relating the facts of my situation so the forum has this info to add to our knowledge of this frustrating issue that's affected a few.

I make no claims of understanding the cause or the solution to the problem. I am not asserting causality. I'm simply relating the facts of my particular case. Hope it helps others.
 
This problem is getting curiouser and curiouser...
 
I just put money down on a new 2017 EX and this issue has me a bit spooked. Enough that I decided to buy the 5 year extended warranty. Seems like one throttle body replacement would easily cover the cost.
 
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