Adjust air bleeds on closed loop?

[clubhousemotorsports]

When you have the air bleeds the screw is closing off the source for additional air to enter the system so closing it off will richen the system.
Except if you have an o2 sensor that senses the rich mixture and the leans out the mixture to compensate.

[Capo]

The mixture can be made richer using the trim function on the ECU

[Monstermash]

Ok, I had it richened up at the dealer using the trim right after I bought it to try and get rid of the surging. However now that I have the O2 unplugged, can they make it leaner to compensate because it's WAY too rich?

[NAKID]

If it's too rich, take advantage of it and open up the airbox a bit more. Oh, when you got the bike dyno'd did you have them read the A/F mix?

[clubhousemotorsports]

Yes they can lean out the ecu as well with the o2 sensor removed. remember though that the o2 sensor only comes into play at low rpm and after you get above that rpm you are on a preprogramed (open loop) system. do not lean it out too much or your top end will be too lean.
It would be best to adjust the trim on the dyno to be sure you are not going to melt anything down and then set the lower rpm zone with a combination of air screw and trim.

[vaclav]

Now we're cookin'. WTF is CO "trim" anyways? Is it just a fancy word for widening the injector pulses? The only trim I know is on planes and something else that has nothing to do with motorcycles.

[Monstermash]

If it's too rich, take advantage of it and open up the airbox a bit more. Oh, when you got the bike dyno'd did you have them read the A/F mix?

 Here's the link to the post with the Dyno results:

 http://ducatimonsterworldwide.org/index.php?topic=2993.0

 In response to opening up the airbox a bit more I have to say I don't like the honking sound it makes when it's fully open. I ran it that way for a few days and it drove me nuts. It also didn't seem to help out that much.

 I am considering a K&N to see if that helps.

[Monstermash]

Ok, so just for laughs I started messing around with the adjustments on the air bleeds.

 I ended up turning the screws counter-clockwise about 2 full turns to add air and the bike seems to be running much smoother. It has more power everywhere and has no surging or popping on Decel. 

 The only downside is that the idle is now a little higher. It's right around 1400 RPM's now but I can live with it to get the bike to run right.  [moto]

[NAKID]

2 FULL turns? That's a huge adjustment!

[Monstermash]

2 FULL turns? That's a huge adjustment!

 I know but my dealer had them almost fully closed from when he was trying to get it to run right with the O2 still connected. It made a difference but it still popped and surged so I removed the O2 and have been running it like that but it was way too rich. Now with the bleeds opened up it runs awsome, like it should have from the factory.

[Howie]

My not so good memory recalls some SR2 1000s running lean with the O₂ disconnected, some rich.  I guess there is no standard base map.  The air bleeds have diminishing effect with increased throttle, so, no backfire, problem solved. 

[Monstermash]

My not so good memory recalls some SR2 1000s running lean with the O₂ disconnected, some rich.  I guess there is no standard base map.  The air bleeds have diminishing effect with increased throttle, so, no backfire, problem solved. 

 Well yes, and no. I still think there is more power to be had. From my time riding with the O2 connected it felt like it had more power. I just couldn't deal with the surging/backfiring issues. 

[clubhousemotorsports]

If you are looking for more power with unplugging the o2 sensor then it is just not going to happen there is no magic genie that will give you more hp.
driveability it can do with some ecu/tune trickery. but if you are not getting more air and fuel into the motor you will not get more hp out.
also remember that an aftermarket ecu does more than just adjust fuel. it also adjusts ignition timing, red line and the fuel map (when the fuel is delivered as well as how much).

CO is carbon monoxide, you know the stuff that kills. It is the product of unburned combustion, so too much CO = too rich a mixture (or too lean but thats another story).
It is used as a giudeline reading for how well the engine is using its air fuel mixture.