Any Yamaha mechanics lurking here?

[Kevhunts]

I was thumbing through the service manual and under the section for periodic maintenance, there is a section on "adjusting exhaust gas volume & CO density levels" from the display meter while in diagnostic mode.

I've never heard of an adjustment like this on a ECM controlled system before. I was wondering if this is needed because of the YCC-T system?

I also wonder if this needs to be recalibrated after replacing the stock exhaust system?

 

[HoebSTer]

i saw that too. I think that if when WASP mounted his exhaust, he might of mentioned this. Maybe not of course. I wonder what that is.

 

[supert]

One of the nice things about owning a FJR was all the great technical info available on-line. Warchild's web site had the procedure for adjusting the CO setting which required a jumper wire in the wiring harness. I did not have any lean surging problems as reported by some owners, but my bike ran much smoother (especially off idle) with the adjustment.

http://www.fjrtech.com/getdbitem.cfm?item=26

 

[Waspworks]

i saw that too. I think that if when WASP mounted his exhaust, he might of mentioned this. Maybe not of course. I wonder what that is.

Myself and another S10 owner on the eastern side of Aus have played with this adjustment with no appreciable change that we could document.
It is not something I would adjust (long term) without the benefit of having a sniffer connected to see where the AFR is after adjustment.
My bike will be going back on the dyno soon to test a number of different exhaust/muffler configurations but only after I have access to the Power-Commander that is in development at the moment.
So the short answers are:
1/ yes, I have played with it.
2/ no, I did not notice much/any change.
3/ no I would not change it again until I can record the outcome.

Greg.

 

[Kevhunts]

One of the nice things about owning a FJR was all the great technical info available on-line. Warchild's web site had the procedure for adjusting the CO setting which required a jumper wire in the wiring harness. I did not have any lean surging problems as reported by some owners, but my bike ran much smoother (especially off idle) with the adjustment.

http://www.fjrtech.com/getdbitem.cfm?item=26

So what I get out of this is, this adjustment need only be changed if you are experiencing some kind of "lean surge issue" and then should only be attempted with the proper exhaust gas test equipment. Tweaking these settings to squeeze out a little better performance may bite you later on in the form of a fouled catalytic convertor. (I noticed the manual listed no specifications for CO , could these be based on local regulations (Calif. vs. 49 state vs. Europe)??

I will likely jot down my "from the factory" settings for reference later on if needed.

 

[bvail]

I had an '03 FJR and did just about every mod possible while I owned it. The cheapest mod (free) was the 'Barbarian Jumper' as mentioned in this thread. Google it and you will come up with many threads. My issue was that the ECU would be hunting while cruising through a small town to get to the other side of the 'blue' highway. Usually in second or third gear. Cause was very lean settings for CO. Fix was moving one wire on the ECU and jumping two connections with a itty-bitty piece of wire. Then access the control panel for the clock/trip odo, etc and fiddle with buttons and run the CO up on each cylinder. But, one had to write down the initial settings for each cylinder before proceeding or it would be a real problem returning the settings to factory specs, since each bike was set at the factory. I wrote the before/after settings in my service manual. Once I performed this, no more issues with the ECU hunting and the bike chugging.

 

[markjenn]

When I read that section in the service manual, I get the impression you're calibrating some kind of reading or sensor, not actually making a change in the way the engine runs. Just my impression....

- Mark

 

[Hipshot]

The FJR forum was and still is a wonderful and informative site. I knew more about the 05 FJR than any bike previous and it was before I took delivery. I made a notebook of procedures and maintenance that was 1" thick.

 

[bvail]

When I read that section in the service manual, I get the impression you're calibrating some kind of reading or sensor, not actually making a change in the way the engine runs. Just my impression....

- Mark

I believe that some installed a port in the exhaust to test co, but most, like me, did it in the blind using bump ups in each cylinder from previous recommendations. I did not know what the actual co readings were, just that the bike ran a lot smoother and some thought it ran a bit cooler because the mix was less on the lean side.

 

[troll]

There is great value in learning how EFI systems work, and then applying that knowledge to the system used on the SupaT. I have yet to research and fully understand the SupaT EFI system, but o2 sensors usually control the AFR through the ECU. I believe the SupaT uses a closed loop EFI system which puts the o2 sensor feed back in control of the fuel system. It will be interesting to read more as tuners start to hack the SupaT EFI system.

 

[Koinz]

I believe the SupaT uses a closed loop EFI system which puts the o2 sensor feed back in control of the fuel system

I believe you are correct. Closed loop when the engine warms up. I think it works with the air temperature sensor as well. I've heard people tricking the temp sensor with resistors to eliminate surging issues on other bikes. It's also why fuel economy gets bad in the colder temps.
The vstrom doesn't use an O2 sensor, so it's mixture is controlled from the fuel maps and temp sensor.