CB1100 Idle speed instability problem

[max]

Thanks Mechanix, there seems to be a relation ship with higher temperatures, not clear why for now but you are not the first to link the ii issue to warm conditions.

Could you explain in more detail what happens when the clutch is engaged? is the engine warmed up, does it happen consistently, does the idle return when the clutch is released etc.

It would help your case if you could document the situation with appropriate comment on the video and show them what happens and how often it occurs, even better post it on youtube so everybody can see it, also get some sort of proof that you made the dealer aware of this idle behaviour ( witness ) and when before the warranty runs out, according to my nz dealer Honda do stand behind their product even after the warranty expires but require strong proof to do so.

max

[SportsterDoc]

Ditto on Max's question about clutch engagement.
I typically give it a bit of throttle while releasing the clutch, so an increase in RPMs would be expected.

High or low idle can be an IACV symptom. Could also be a vacuum leak. Have you snugged the 8 hose clamps from throttle bodies to intake manifold?

[DaSwami_imp]

Still no answer re: VIN's? Is this a random occurrence or linked to a VIN range?

[SportsterDoc]

Still no answer re: VIN's? Is this a random occurrence or linked to a VIN range?

Don't think we've had an answer.

You may want to browse the Curly Joe spreadsheet

http://cb1100forum.com/forum/showthread.php?tid=11247

[max]

Still no answer re: VIN's? Is this a random occurrence or linked to a VIN range?

Swami we would like to get a handle on the affected vin's too, if it is a risk of theft and illicit registering aspect maybe just provide a number that spoofs the last one or two digits, ie; 110002400 instead of 110002456, that should be safe enough, we are only interested in the 1000 range , in this case 24_ _.

and maybe a new column in the spreadsheet for this purpose,what do you think?

[kennyw]

My 2013 has developed this issue as well after 50K miles. I'm not sure you will find a range of VIN #'s particularly helpful.

[max]

My 2013 has developed this issue as well after 50K miles. I'm not sure you will find a range of VIN #'s particularly helpful.

Hi Kenny, interesting about the issue after 50k miles, yep, makes ya think.

How did yours start and how bad is it?
Have you been following Dave's case?

Thanks for chiming in

max

[Mechanix_imp]

Thanks Mechanix, there seems to be a relation ship with higher temperatures, not clear why for now but you are not the first to link the ii issue to warm conditions.

Could you explain in more detail what happens when the clutch is engaged? is the engine warmed up, does it happen consistently, does the idle return when the clutch is released etc.

It would help your case if you could document the situation with appropriate comment on the video and show them what happens and how often it occurs, even better post it on youtube so everybody can see it, also get some sort of proof that you made the dealer aware of this idle behaviour ( witness ) and when before the warranty runs out, according to my nz dealer Honda do stand behind their product even after the warranty expires but require strong proof to do so.

max

Well, I have video of the low idle issue, I hope to get a video of the idle increase when cold and clutch being released.

What happens is when it’s cold (I’m guessing below 55degrees) the idle is a bit high...normal. But when I begin to release the clutch (without any throttle) the rpm goes up to almost 1700. I usually use two fingers for my clutch and when the lever is pulled back there is no clutch engagement but still a bit more lever to pull. If I do not pull the lever past a certain point the rpm will stay high...until the lever is pulled back to the grip. Make any sense?

I have a 5 mile ride to work and this high idle clutch issue will happen for 4 miles of that...in the cold.

Ditto on Max's question about clutch engagement.
I typically give it a bit of throttle while releasing the clutch, so an increase in RPMs would be expected.

High or low idle can be an IACV symptom. Could also be a vacuum leak. Have you snugged the 8 hose clamps from throttle bodies to intake manifold?

I’ve checked the clamps...all tight. I also went through to make sure all hoses were tight and in place, all plugs secure and free of any corrosion or pinched/damaged wires.

Normally I give it a bit of throttle too when getting started but it seems when it is not completely warmed up it will increase the rpm’s when the clutch starts to be released...almost as if the idle is tied into the safety switch to the clutch. I do not have a wiring diagram or a service manual yet so I’m not sure how this is all set up.

I’m starting a log in the morning if it’s not too late with the weather changing over here in the valley.

[max]

Hi Mech, looking at your part of the spreadsheet i assume that is the video you refer to ( correct me if i am wrong at any stage ).

So the engine is cold, started and idling at 1500 rpm as they normally do, but when you pull the clutch in it idles at 1700 rpm instead,unless the lever is pulled close to the handle and drops back to 1500 rpm ( had to read your explanation 6 times and i think this is what you mean ).

It is possible that because of the cold temperature the engine idles at 1700 instead of 1500 rpm.

Just checked and the switch on the clutch is open when the lever is forward, and closes if the lever is pulled back, you can hear when it operates.
The wiring is hard wired ( not dependant on the elecrtonic control module ) but does provide input TO the ecm.
That means the clutch, neutral and sidestand work to prevent starting even if the ecm is faulty.
The inputs to the ecm are; b22 sstand and b33 nl sw.

To verify if it is the switch you can pull one connector off and confirm the switch is causing the change in rpm.

here is the diagram courtesy of popgun





Question is; has it always been like this in below 55 degrees or is this new behaviour that started with low idle, my guess is it is not related but who knows.

Interesting about the warmup period of 4 miles, do the rpm's gradually lower when the engine heats up or is there a sudden drop and when does the low idle start?

Thanks for checking the clamps.

[kennyw]

My bike is only having the issue in hot weather (90F+) combined with stop and go traffic. Not a single problem since last August though. Last August is also the first time I experienced the symptoms to the extent of the bike dieing.

I'm willing to bet my case is wear or corrosion starting to affect the performance of something rather than defective parts from the factory.

I park indoors at home and outdoors at work. I ride in all weather conditions except snow. My bike gets washed twice a year, if it needs it or not.