Too lean too lean toooo lean

[turboflyer]

Just pulled the plugs at 10K on my 05 BCP. I was hopeful the ECU would compensate enough for the K&N and CAT removal. Alas not so. Could be different on other similar R1100S bikes but I doubt it. Now do I put the CAT back on or invest in one of several remap kits like dynojet. Who has done this and achieved a nice dark grey plug reading?

[markjenn]

I don't think "dark grey" is the optimal plug color.

http://www.centuryperformance.com/spark-plug-reading-spg-192.html

And are you doing your plug check at speed or idle? If the bike is running fine, I doubt you need to do anything.

- Mark

[blutruck1]

Best bet would be a Power Comander I believe. It uses a closed loop system to adjust and maintain A/F ratio (13.8:1) through the EGO sensor. It compensates for the stock BMW mapping and can be fine tuned on a dyno. Stock BMW fuel injection runs off installed fuel maps and doesn't use the EGO sensor much, if at all.
Putting the cat back on just brings on weight and heat, it's not going to change the stock BMW fuel mapping, nor change the plug color.
Others are going to chime in sooner or later, so you should have a myriad amount of opinions soon.

[shreddr]

The Techlusion is a very simple solution to your problem, and you can pick them up on eBay or other places very inexpensively.

[bacn5]

I agree with MarkJenn... If the bike is running good, you are most likely okay. I have a five gas analyzer, and the majority of the time when I get the AF-Ratio right the plugs are mostly white with a very light grayish/ tan band or stripe. With today's fuel the insulator should not be dark grey.
I have been playing around with my Power Commander a lot lately and have found that under most conditions I have had to subtract fuel. I would send you the maps but I am not running a stock prom either. I am currently running a SJBMW power filter and a Remus dual exhaust along with several other mods.

[bacn5]

blutruck1, I have found that my bike starts best (cold or hot), runs and idles smoothest with closed loop set at 14.6 -1. However, during WOT I shoot for 13.8 -1. Some tuners like to go closer to12.8-1 under WOT and I am open to going richer under WOT if someone has dyno time showing HP and torque gains on our motors. But personally, I've watch my A/F ratio gauge real close and whenever the engine isn't running as well as I like, it's always because it is richer than 14.6-1. With that being said, I never let the AFR go leaner than 14.8-1.

[blutruck1]

bacn5 sent you a pm. I want/need more info. Thanks, blutruck1

[roger albert]

Base power commanders are not full control systems and don't use the lambda sensor any more than the stock system does, which by the way, is quite a lot and low to moderate throttle, not "doesn't use the EGO sensor much, if at all"

This is all pretty well documented on older threads, but in general, you can't expect much compensation from the lambda sensor since it is only capable of trimming at low loads. These bikes remain w/o an air sensor, which means they are still running mapped, even if that is a tweaked map by any of the myriad variants now available.

[turboflyer]

Here is a pic, all be it crap, of the 10K original plugs. I had planned on the wide ban unit with a ratio gage. That is what I need to be able to adjust things, right? Also how does one get to the PM? Thanks

[roger albert]

Plugs on right look fine. left-middle not bad. Far left is odd. Wideband is definitely the way to go. Much larger trim range.

[bacn5]

Originally Posted by turboflyer

Here is a pic, all be it crap, of the 10K original plugs. I had planned on the wide ban unit with a ratio gage. That is what I need to be able to adjust things, right? Also how does one get to the PM? Thanks

The one on the left looks looks like you may have a bad wire, coil or plug. Search the forum as I recall someone else who had one plug of the dual plug heads not firing. Fix this first before other mods.

[turboflyer]

Thanks to all for the help. Sure is nice be able to share knowledge. After finishing the service and finding the tops of the pistons nice and black I am going to for go the modules for now. The bike runs like a top, balance was perfect and unchanged from the 600 service. The valves were perfect not adjustment required. I think the dead plug idea is a real possibility. Just did not correlate to the sister plug. Idle seem smoother and more responsive. Will know a bit more on the next ride. I think I will change over to the iridium plugs for both primary and secondary plugs next service. Had the piston tops been white or even light color I think I would fatten things up, but just does not seem necessary at this point.

[roger albert]

Very little you can read from piston top. Even a really lean bike will not have a clean piston.

[bacn5]

I would recommend pulling the wire from the dark plug and see if the spark is as strong as the others.

[wood-d]

That thread on troubleshooting dual-spark is here:
Troubleshooting Dual Spark ignition

DAMHIK ;-)