So I have the left outer cylinder, if sitting on the bike, running rich. I just installed a full Delkevic exhaust, stock air filter, PCV with the yoshi map. At first I ran the stock map and didn't have the O2 sensor installed and went for a quick ride. Obviously the check engine light was on, but the bike ran better than stock. After returning, I noticed 3 of the 4 headers had changed to the bronze color, but the one was still silver and new looking. I pulled the plug and it was dark brown and shiny, the others a nice light tan. I next put the O2 sensor in and went for a ride. On the highway, the lower end felt fat or blah, but the top end was much better and was able to pull 90mph with relative ease. The stock bike could hardly hit 80mph. I live at 5300'. After returning, the one pipe was still silver showing it was still running rich. I then loaded the yoshi map and it made the lower end much better and very responsive, but the upper end was back to blah. The 2 maps are very different and the yoshi one takes fuel away which is the opposite of what I'd expect? Dynojet is of little help other than trying to sell an auto tune. Anyways, sorry for the winded story, but does anyone know why one cylinder would be running rich? Could the power commander cause this or is the fuel injector need replaced? Could running without the O2 sensor have caused a single cylinder to run rich as a default kinda thing? Thanks for any and all help!
1 cylinder running rich?
- Thread starter frank_imp
- Start date
noroomtomove
Been there
I'm interested in how this works out.
Regards NRTM
Regards NRTM
GoldOxide_imp
Road warrior
Is it common for bikes like the CB1100 to not easily do the ton at 5300 feet attitude?
My recollection is that members at altitude have previously talked about how well the CB1100 performs.
teamvisegrip_imp
Running like a top
If I may add my thoughts on this one...
3 of your 4 pipes are hot and discolored. Your Left Cylinder is not discolored or hot. Hondas are amazing bikes and rarely fail. But the non-Honda items might. My suggestion is to replace that spark plug or check the boot to be sure that there is a good connection. Sounds like there is no spark or limited spark in that cylinder.
Good luck.
3 of your 4 pipes are hot and discolored. Your Left Cylinder is not discolored or hot. Hondas are amazing bikes and rarely fail. But the non-Honda items might. My suggestion is to replace that spark plug or check the boot to be sure that there is a good connection. Sounds like there is no spark or limited spark in that cylinder.
Good luck.
Thanks for the responses! I was going up a hill, not super steep but sustained. The top end in Colorado is lacking and the main reason I wanted to open this bike up. I was planning on swapping plug 1 with 4 and seeing if the color remains. I'm assuming your thoughts are the injectors are delivering equally and the power commander delivers to all cylinders/injectors equally as well? I'd love it to be the simplest and maybe the reason the bike seemed like a dog in stock form. The bike has always idled and sounded smooth, never ran or sounded like it was missing. I pulled the opposite outer plug before I did the mods to see how it was running, so I don't know if the rich cylinder has always been rich or only after adding the pipe/PCV. Thanks again for all responses and I'll report back what I find with the plug swap.
Houtman_imp
Road warrior
It could be as simple as a "bad " plug , in a recent F1 race one car had a problem with plugs. On one of my CBX's I had a problem as the bike run on 5 cylinders , new plug in one of the outer cylinder cured the problem . It is a cheap "first repair "
LongRanger_imp
Road warrior
I don’t think it’s the altitude. I rarely ran that hard, but my ‘14 would hold 90-100 mph on uphill stretches at altitude (Copper Mountain to Leadville via Fremont Pass, for example, which is 11,300 feet).
PowerDubs_imp
Road warrior
You mention dark brown and shiny.
I wonder if you are burning oil.
Might want to do compression and leak down tests.
I wonder if you are burning oil.
Might want to do compression and leak down tests.
GoldOxide_imp
Road warrior
(+1) My thoughts as well.PowerDubs_imp said:
teamvisegrip_imp
Running like a top
I live by one rule over all.... KISS Keep It Simple Stupid. So many times I have been burned by this simple saying.
You have been given a lot of good info.
1. Test for Spark. To verify the Spark Plug Boot is good and it has spark for that cylinder.
2. If not... Replace the Spark Plug. Try again for spark.
3. If you have spark move on to a Compression Test on that Cylinder. If this fails you have a large problem. I still feel that the Spark Plug, Boot or possibly a chafed lead is your issue. Could also be a simple as a loose connection with the repairs you have done?
I hope you figure this out.
You have been given a lot of good info.
1. Test for Spark. To verify the Spark Plug Boot is good and it has spark for that cylinder.
2. If not... Replace the Spark Plug. Try again for spark.
3. If you have spark move on to a Compression Test on that Cylinder. If this fails you have a large problem. I still feel that the Spark Plug, Boot or possibly a chafed lead is your issue. Could also be a simple as a loose connection with the repairs you have done?
I hope you figure this out.
LongRanger_imp
Road warrior
Frank, 100% stock, but I no longer have the bike. I can’t believe you’d have any trouble on 93 — that stretch of road is what, 6000 feet elevation? Maybe 6500 max?frank_imp said:
I couldn't agree more teamvisegrip! The plug doesn't look like oil burn, but rich. I swapped the outer most cylinder plugs with each other. The gaps were good. I'm going to check the exhaust temps with an IR gun and then ride it around today once the temps warm up.
LR, I agree that the road I was riding wasn't that steep or high and was surprised by the lack of high end power which led me to think this bike was strangled for air and fuel. If the suspect cylinder is still running rich, I'll check the spark and drop a scope in the cylinder. I'm assuming a typical plug check won't cause harm, meaning ground the plug to the cylinder and hit the starter which will cause the bike to probably run on 3 cylinders for the test and look for a good blue spark? I don't want to smoke anything electrical running this test. Thanks again for everyone's comments!
LR, I agree that the road I was riding wasn't that steep or high and was surprised by the lack of high end power which led me to think this bike was strangled for air and fuel. If the suspect cylinder is still running rich, I'll check the spark and drop a scope in the cylinder. I'm assuming a typical plug check won't cause harm, meaning ground the plug to the cylinder and hit the starter which will cause the bike to probably run on 3 cylinders for the test and look for a good blue spark? I don't want to smoke anything electrical running this test. Thanks again for everyone's comments!
The A-man
Been there
An alternate suggestion. Go out to a deserted road, and get on the throttle a bit. Then turnaround, go back to the starting point. Stop, reach down and pull the suspect plug wire off, and do the run again. If no noticeable difference in speed or acceleration, then you've confirmed either a bad plug or bad plug wire.
Teamvisegrip, I KISS and it was a bad plug. I checked the pipe temperatures and the cylinder that I moved the bad plug to was now not heating up. Went to Honda and paid $23 for 1 plug, need to find a cheaper source, but the bike is running fantastic!!! What a difference. A little background, I never rode a CB1100, found a mint one with only 2300 miles, rode it and it felt choked down, so I thought. Meanwhile it was only running on 3 cylinders. It ran smoothly, just lacked top end power. I wonder why it didn't throw a check engine code or something? Now my new question is what, if any, damage to what could have occurred running it on 3 for ~700 miles? Mostly highway and I did run it kinda hard and up to 80 mph a few times It's running great now, especially with the mods. The 14" Delkevic sounds awesome by the way for anyone looking. I do have a problem with the centerstand rest on the pipe causing it to spin the pipe and then the centerstand rubs on the chain. I tried to tighten the bracket to the max and it's still spinning. Could I put some high temp RTV and kinda glue it? Any tips would be most helpful!! This joint has one of those carbon sleeves and it makes it a somewhat slick surface and probably why it's spinning. Anyways, thanks to all and be sure to KISS!
Houtman_imp
Road warrior
I am very happy that is was just a bad plug ! ( see post # 8)
For all those years I have been trying to tell you guys that I am ALWAYS right , this proves it once again. For the naysayers about me not being right you must have talked to my wife as after 46 year she still does not get it about me being right all the time.......
For all those years I have been trying to tell you guys that I am ALWAYS right , this proves it once again. For the naysayers about me not being right you must have talked to my wife as after 46 year she still does not get it about me being right all the time.......
peterbaron
Road warrior
:worship: :clap:Houtman_imp said:
teamvisegrip_imp
Running like a top
Possible damage... I would not worry about it too much.
But... there is always a but... if you did run the bike for 700 miles with a dead cylinder I would definitely change the oil. The unburnt fuel may have polluted the oil. Just change it and the filter to be safe.
So glad it was something simple. No go enjoy that wonderful machine.
But... there is always a but... if you did run the bike for 700 miles with a dead cylinder I would definitely change the oil. The unburnt fuel may have polluted the oil. Just change it and the filter to be safe.
So glad it was something simple. No go enjoy that wonderful machine.
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