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Bleed screws


red lion
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Is the setting the same for a 1100 sport and a V11 sport for bleed screw opening?  I have read 1 full turn and 3/4 turn opening. And would matter if air filter is stock or not?

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and a half turn. and fully closed.  Probably not the most critical tuning parameter, relatively speaking . . .

[See the linked pdf Workshop Manual for the 1100 Sport, below, for specifics related to the 1100 Sport.]

 

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21 hours ago, red lion said:

What are you saying by - and a half and fully closed?  The link list one turn out?

I've seen all of these settings. The 1999-2000 V11 Workshop Manual uses 1/2 turn.  Meinolf's Map uses zero. The "Decent Tune-up" has a full turn as a starting point, then turning each in or a out to get a good throttle body balance at idle.  So, certainly not as critical as, say the TPS baseline.

I found that if the two air bypass screws have to be set significantly different (like 1/2 turn) from one another, there is likely a vacuum leak somewhere.

 

Since the ECU is different, I am not certain about the TPS setting, though. Perhaps @Pressureangle or others know . . .

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3 minutes ago, docc said:

I've seen all of these settings. The 1999-2000 V11 Workshop Manual uses 1/2 turn.  Meinolf's Map uses zero. The "Decent Tune-up" has a full turn as a starting point, then turning each in or a out to get a good throttle body balance at idle.  So, certainly not as critical as, say the TPS baseline.

I found that if the two air bypass screws have to be set significantly different (like 1/2 turn) from one another, there is likely a vacuum leak somewhere.

But, yes, to your question - I would think the 1100 Sport could be set the same as the V11.  Since the ECU is different, I am not certain about the TPS setting, though. Perhaps @Pressureangle or others know . . .

I have a Jeffries MyECU. The TPS can be set anywhere from 0.0v to 150mv but you have to edit the text file manually to reflect the idle TPS value. 

There is no way to know the airflow through the airscrew passages. The best theoretical sequence for balancing throttles is to close the butterflies to as close to zero as possible physically, then set idle speed with butterfly position screws, then balance idle vacuum with idle air screws. In practice, there is no need for either or both screws to pass any air at all, as no fuel is drawn in by them and injected fuel must pass the butterflies by moving air so having them open a little farther at idle is a good thing, as long as you can adjust your TPS to suit. If your butterflies are equalized by position at idle, they are equalized by position all the way through their travel; if you have significant variance in vacuum anywhere in the rpm range you have to look elsewhere for the root cause. Usually it's valve adjustment or intake valve carbon deposits. It can also be unbalanced fuel injectors, as the A/F ratio and atomization also contribute to vacuum. Not to be ignored is the likelihood that the camshaft is not perfect with symmetrical timing on both cylinders. You can adjust vacuum slightly by adjusting intake valves differently from side to side. 
All these are reasons I use the 80/20 rule on cylinder balance; I care most about idle quality and light throttle drivability than whether I'm getting 30hp from one cylinder and 34 from the other at 4500rpm.  Adjusting EFI to perfection is a fool's errand if you're not being paid for it. If you're not certain you have everything satisfactory after your tune-up and balance, read your spark plugs. They are the definitive arbiter of your A/F mixture differential. 

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Interesting @Pressureangle

I don't know if I'm setting up my Sport correctly but I close the airbleeds then balance at 2k and 3k rpm on the butterflies the idea is both TB's get the same amount of fuel so I try ensure they get the same amount of air, at 3k hopefully they are starting to flow a reasonable amount of air

Then I set idle using the throttle stop on one side only (other side is screwed way out).

Finally I adjust the air bleeds to balance the TBs at idle.

Correct me on this if I'm wrong but my thinking is the amount of air fed via air bleeds is pretty much insignificant in the scheme of things compared to the butterflies so they've negligable effect at any significant throttle opening.

I agree on the statement regarding getting it perfect I just get it near enough at the 2k and 3k mark and average a little

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My opinion of the purpose of these idle air bleed screws is ; to adjust the idle speed of the bike . You have set the base idle with the throttle plates/TPS .  

You go through each step and do not go backward , but forward .

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4 hours ago, red lion said:

When asking about the bleed screw settings, I am thinking about the bike running lean or rich (the sweet spot) Not as much about balance.

+1 on what Weegie said about the air bleeds being "insignificant . . . at any significant throttle opening."  In other words, do not expect them to change the rich/lean (AFR) condition. This is the function of the "map" in the ECU.

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If I understand the factory 1100 Sport-i ECU correctly, the TPS value is intended to reflect a specific throttle blade position, which guarantees that the fuel map and the airflow match up correctly. If that's the case, idle speed needs the separate adjustment of air screws. I'm not familiar enough to make intelligent comment beyond that. 
 

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You have a Workshop Manual for the 1100 Sport?

https://www.thisoldtractor.com/mg_manuals/workshop_manual_v10-centuaro_daytona-rs_1100-sport_en.pdf

Section 12.6 looks very much like the V11 manual. The TPS is adjusted in the fully closed plate position to show 150mV +/- 15 mV.

Idle speed set using the idle stop screw(s).

And, #8, "Open by one turn the air bypass screws."

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