CB1100 Idle speed instability problem

[Lord Popgun]

Humm, now I see what you are talking about. I’ll have to study the manual some more. From what I can tell, our valve doesn’t mount like that one. It doesn’t mount in a separate assembly bolted to the body.

Still, maybe there is a way to make it easier.

[max]

Just looking at a picture that i "found" on ebay for a cb1100 throttle body it seems identical to the one in the video, looking at the right hand housing with the two rubber hoses.



looks at least "plausible" to me but would work better if the locking plate and the hoses were pulled out of the iacv assembly by removing the single screw first in any order.



Yellow line points to single screw to be removed first for better access to iacv assy.

You can see where the assy splits from the throttle body near the blue felt tip mark and the same place as the other hose plate on the left.
Cick and click again for large picture on the point where you want to view close up.

[Magnus_imp]

On our CB1100 there is just no room to remove the IACV even if you could get the retaining screws off. The airbox totally blocks it and no way of getting the throttle bodies out as far as I can tell without removing the airbox.

Dave, open the vid. Run the cursor to the 19 min point and click run.

Personally, I’m not seeing it. He already has the throttle body off the bike (not a CB1100).

The end was pretty neat where he shows his rig for cleaning injectors.

So what would happen if you leave the whole bike intact, lift the tank, remove only the right hand black throttle body cover and just take out the three security torx screws for the iacv plate from the top.
unclip the 4 pole connector and lift the iacv up and out of the bike, swap the iacv, put the plate with new iacv back in the bike and re-connect the 4 pole connector; that's all.

That is what he does at 20 minutes, our bike stays together.
Yes it's a different model bike but the throttle body is the same.

What do you think, Dave?

Even if you are taking your time it could be swapped inside one hour.
Does the service manual mention anything about replacing the iacv popgun?

So what would happen if you leave the whole bike intact, lift the tank, remove only the right hand black throttle body cover and just take out the three security torx screws for the iacv plate from the top.
unclip the 4 pole connector and lift the iacv up and out of the bike, swap the iacv, put the plate with new iacv back in the bike and re-connect the 4 pole connector; that's all.

That is what he does at 20 minutes, our bike stays together.
Yes it's a different model bike but the throttle body is the same.

What do you think, Dave?

Even if you are taking your time it could be swapped inside one hour.
Does the service manual mention anything about replacing the iacv popgun? I believe the IACV is not accessed via the area you marked. It is mounted to the other side of the throttle body

Just looking at a picture that i "found" on ebay for a cb1100 throttle body it seems identical to the one in the video, looking at the right hand housing with the two rubber hoses.



looks at least "plausible" to me but would work better if the locking plate and the hoses were pulled out of the iacv assembly by removing the single screw first in any order.



Yellow line points to single screw to be removed first for better access to iacv assy.

You can see where the assy splits from the throttle body near the blue felt tip mark and the same place as the other hose plate on the left.
Cick and click again for large picture on the point where you want to view close up.

[max]

Hi Magnus good to have your opinion, i thought it was more clearcut than it seems.
Here are the basics; rather than removing so many parts you leave the entire bike in tact and just give yourself room to work by lifting the tank and remove the righthand black plastic throttle body cover only.

You can now remove the iacv module by taking the two rubber hoses from the top and unscrewing the three security torx screws on the top of the throttle body.
As you can see from the video-------------- the MODULE now lifts straight up and out of the bike,--------------- complete with iacv valve, click on "image" below to watch the 25 second video;




see?

The pictures above relate to popgun's advice, he thought our system was different and the module could not be removed from the tb, the picture shows that the module is in fact a separate unit like the one shown in the video and can be removed straight up and out like the video shows.

[dave]

[quote='max' pid='216762' dateline='1535490551']
Hi Magnus good to have your opinion, i thought it was more clearcut than it seems.

Magnus is correct. There is no way to remove the IACV attachment screws without first removing the entire air filter assembly. I did not remove the throttle body assembly from my bike to replace the IACV, but to get the air box off you have to remove the entire battery box and rear fender first.

[dave]

I watched the video clip that Max attached. Before the housing that the IACV is attached to can be removed the black, plastic runner that links each of the throttle bodies together must be removed first - this part is already removed in the video so don't look for it in the clip Max posted. I do not believe it is possible to access the two, center bolts of this runner without removing the air box. But who knows, maybe somebody can figure it out. I certainly would like to hear it if somebody does this.

[max]

Well Dave is 100% right and i goofed up, i completely missed the fact that the fuel line sits on top of the iacv module.
It took me a few days to work this out but after getting a new 8mm spanner and grinding it down to get in between the bolts and the airbox i was still not able to undo the two inside ones, i managed to change the shape of the airbox with a heat gun on the left but it was too risky next to the fuel line to do the same for the two in the middle, the bolts do not have enough room to unscrew without hitting the airbox.

So sorry about the confusion i caused, i just watched the clip and the minute he removed the iacv module up and out of the throttle body i got very exited and posted the clip but never checked it on the bike because it was packed away for winter, only after Dave explained about the fuel line i removed the tank and side panels and tried it out on the bike.
On a positive note i am getting much better at removing and replacing the fuel tank and popgun's way of putting the blue clip in first works fine, i just put a very small amount of grease on the fuel pipe and the front mounting rubbers and the job is easy to assemble.
Thank You Dave for pointing out the mistake i made !

[SportsterDoc]

Kudos to you Max for seeking less steps to IACV replacement.
Nothing ventured, nothing learned.

[Lord Popgun]

What SportsterDoc said!

[dave]

Max - you're incredible! You went through so much work, even to the point of reforming (damaging) your air box, just to help fellow owners! WOW! I wish your idea had worked.

By the way, roughly 1,500 miles since the IACV replacement and it is still running better than new, so I believe it is safe to say that the IACV was the root cause of my idle issues.

I spent the $ I saved by doing my own IACV replacement on a new set of 2017 Honda CB1100 forks. I was going to buy shocks, but the fork replacement really intrigued me when I read about other members doing the swap. In summary (I'll report more in the thread about forks) I am impressed with the ride improvement, and this is after only a short (6 mile) test ride.