Please explain CO levels


28 replies to this topic
  • judgnot

Posted July 31, 2014 - 08:05 AM

#1

I'm buying a wr450 soon and trying to educate up on FI.  

 

I understand I'll want to uncork the bike and play with maps until I find what I like.

 

What I'd like to know more about is CO settings.  What exactly are we doing guys when changing this?  My mind tells me the altered CO setting is just the byproduct of the real change.  Raised CO levels tend to come from other than ideal combustion..  

 

I'll buy the ECU and tuner but i want the dealer to set my CO as part of the deal. Sounds like I'll benefit from being up around the 8 mark or more. When I ask him to get his fancy tools out to carry this out I'd like to know what exactly is happening.  Any help?  Thanks.



  • vlxjim

Posted July 31, 2014 - 11:41 AM

#2

All he is doing is bumping up the Fuel at idle. Its just like changing the pilot jet on a carb bike. On the FI tool there is a menu for CO adjustment. The base is at 0 so bumping it up to 8 is like going 1 up on the pilot. The power programer does not allow this adjustment. Yes and adding more fuel is going to raise the CO%. But keep in mind that the fuel at idle is to lean stock.



  • Krannie McKranface

Posted July 31, 2014 - 03:31 PM

#3

 airfuel_zps5f492106.jpg



  • Krannie McKranface

Posted July 31, 2014 - 03:39 PM

#4

131744635.luf8M9rh.KTM350SXFGreen02468d.

 

 

 

This is not of a WR, but it shows a tuner changing A/F ratios  

Each color represents a tuner postion, red being leanest, black being richest.

 

Stock, the WR comes with A/F ratios approaching 15! This is extremely lean; hence the need for a tuner to bring them back as close to 13 as possible

You can see the 'green' setting is the best choice here, seeing as how this tuner has only one setting for a wide range of rpms (Power commander type)

A more sophisticated tuner (Yam factory, Honda PCM tool, etc) can adjust F/I ratio every 500 rpms, along with timing changes concurrent, depending on throttle position.


Edited by Kah Ran Nee, July 31, 2014 - 03:43 PM.


  • GP1K

Posted July 31, 2014 - 03:45 PM

#5

 airfuel_zps5f492106.jpg

 

Do you know off the top of your head what the CO numbers everyone is setting their bikes to (8-15 seems most common) is in percentage? There's a lot going on in that graph... am I correct in assuming CO of 3-5% would be ideal?



  • Krannie McKranface

Posted July 31, 2014 - 04:19 PM

#6

I am not an expert

Do more research on the subject......like I just did for you..... and figure it out.

 

Your goal is to run the engine as lean as possible and still be making maximum HP.

That is very hard to do with stock FI, as the provided tuners are rudimentry at best.

The factory tuners are fantastic, because they allow for more than a +/- 10% change in everything, which scares Yamaha that someone might blow up their motor....



  • vlxjim

Posted July 31, 2014 - 05:57 PM

#7

It's good to run around 4% +- .5%. Stock, there around 2%. And thats were the EPA thinks that a lot of CO emissions come from. Thats why all motors have the darn idle mix screws plug or lock up. I run 15 on the CO setting. I think 20 is to rich. I could drop down to12 or 13. But 15 works good so thats were I run.

 

 

Here is my map give it a try. 

 

Vlxjim Map

 

 Fuel         Timing

3  4  4      0   0   0

3  5  3     -2  -1  0

3  4  3     -2  -2  0


Edited by vlxjim, July 31, 2014 - 06:04 PM.


  • RMK800

Posted July 31, 2014 - 06:11 PM

#8

It's good to run around 4% +- .5%. Stock, there around 2%. And thats were the EPA thinks that a lot of CO emissions come from. Thats why all motors have the darn idle mix screws plug or lock up. I run 15 on the CO setting. I think 20 is to rich. I could drop down to12 or 13. But 15 works good so thats were I run.


Here is my map give it a try.

Vlxjim Map

Fuel Timing
3 4 4 0 0 0
3 5 3 -2 -1 0
3 4 3 -2 -2 0


Just curios is the CO setting independent of elevation. I don't have fuel injected and I run fairly high altitude and I find that going bigger in the pilot doesn't help and can make things worse when the bike gets hot. If you were running high altitude like between 4500 to 9000 would you lower the CO?

  • Krannie McKranface

Posted July 31, 2014 - 06:24 PM

#9

Just curios is the CO setting independent of elevation. I don't have fuel injected and I run fairly high altitude and I find that going bigger in the pilot doesn't help and can make things worse when the bike gets hot. If you were running high altitude like between 4500 to 9000 would you lower the CO?

 

Higher altitude means less concentration of Oxygen....so you would run a SMALLER pilot jet, not larger.



  • vlxjim

Posted July 31, 2014 - 08:06 PM

#10

Once set only on a FI bike it will adjust for altitude.


Edited by vlxjim, August 01, 2014 - 07:53 AM.


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  • Krannie McKranface

Posted July 31, 2014 - 08:11 PM

#11

Once set only on a FI bike it well adjust for altitude.

 

 

If that were the case, why is everyone altering there stock mapping?

 

Because it only adjusts +/- 10% from baseline, and if baseline is too lean already, it will not adjust for altitude requirement. 

 

You still have to correct for basline, AND re-map for extreme altitudes.

 

Only a closed loop FI system can self correct for actual F/A ratio needs.



  • vlxjim

Posted August 01, 2014 - 07:52 AM

#12

If that were the case, why is everyone altering there stock mapping?

 

Because it only adjusts +/- 10% from baseline, and if baseline is too lean already, it will not adjust for altitude requirement. 

 

You still have to correct for basline, AND re-map for extreme altitudes.

 

Only a closed loop FI system can self correct for actual F/A ratio needs.

 

We need to adjust the stock map because it is to lean and to adjust for mods.

 

The base line is just a starting point for the look up table. 

 

But once adjusted the ECU will adjust for altitude and temp. Its not like if you put all -9's in the map that the ECU could not adjust it learner if needed.

 

The ECU is not limited by the look up table. Its the user that limited by the look up table.

 

It will not change the A/F ratio. But will change the fuel amount based on the pressure and temp change to keep the same A/F ratio at different air pressurees and temps.

 

I can go from sea level to 7000+ and its still in tune. I just lose power at 7000 do to lower air density. And the only way to make up for low air density is to super charge or turbo charge.



  • Spud786

Posted December 26, 2014 - 07:20 AM

#13

So I found a Yamaha FI diagnostic tool for like $150, this would work on the wr450 for changing co levels at idle?

Also with this tool can you also adjust the fuel mapping beyond idle

Ecu GTYR $100

Tuner GTYR $250

Fi tool $150

Edited by Spud786, December 26, 2014 - 07:21 AM.


  • grayracer513

Posted December 26, 2014 - 07:46 AM

#14

If that were the case, why is everyone altering there stock mapping?

 

Because it only adjusts +/- 10% from baseline, and if baseline is too lean already, it will not adjust for altitude requirement. 

 

You still have to correct for basline, AND re-map for extreme altitudes.

 

Only a closed loop FI system can self correct for actual F/A ratio needs.

 

Your logic is backward; if the bike tends to be lean, and high altitudes call for leaner fuel delivery, how does that make things harder, exactly?

 

Your fourth sentence here is just false.



  • AtomicGeo

Posted December 26, 2014 - 08:47 AM

#15

I am at 7000 ft and have the GYTR exhaust & tuner and the FI tool. I ride upwards from that base altitude.  At 7000 ft, the CO setting of 0 is way too lean...it has a hard time starting cold and warm.  I went to CO of 8 and it is better at starting cold, but still too lean.  I am looking at going to what vlxjim has (CO of about 12).   So, I am having to enrich even at altitude.  



  • grayracer513

Posted December 26, 2014 - 09:24 AM

#16

 I am having to enrich even at altitude.  

 

Yes, because the bike is too lean at idle, and it compensates for altitude.  Because of that, it's the same "too lean" at any altitude.



  • beezer

Posted December 26, 2014 - 09:56 AM

#17

So does the FI correct for temp and altitude on the Yamaha?



  • woods-rider

Posted December 26, 2014 - 10:41 AM

#18

So does the FI correct for temp and altitude on the Yamaha?


Yes it does.

  • grayracer513

Posted December 26, 2014 - 10:53 AM

#19

That is why it has a barometric pressure and intake air temp sensor.

  • Krannie McKranface

Posted December 26, 2014 - 04:22 PM

#20

But it does not go to the 'correct' F/A ratio, it just adjusts relative to altitude from baseline.

So if it starts lean, it still is lean; but not more lean, when you go up in altitude.






 
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