TB Syncing Question

Discussion in 'Crazy-Awesome almost Dakar racers (950/990cc)' started by Pistolero, Feb 12, 2013.

  1. Pistolero

    Pistolero W. F. O.

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    Hey folks, I read how to sync the carbs on the 950 in the OC HOW (pretty straight forward just like any other bike I have ever done) but my question is on my 990 when I sync the throttle bodies will the bike adjust the idle on it's own or will I have to do some computer magic?

    Thanks in advance! :freaky
    #1
  2. Katoom119

    Katoom119 Mmmm....Orange Kool-aid

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    I'll readily admit, I'm not the brightest Crayon in the tool shed, but I don't think we have to worry about that. I think the computer controls all that. I'll go look in the service manual for you though.
    #2
  3. Pistolero

    Pistolero W. F. O.

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    I have a manual but it only touches on the 950 and not the FI model anywhere I can find. I could be missing it.
    #3
  4. Pistolero

    Pistolero W. F. O.

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    Unfortunately I'm also not the sharpest lightbulb in the shed.
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  5. Katoom119

    Katoom119 Mmmm....Orange Kool-aid

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    I have been known to be a few pickles shy of a full deck.

    I do have information, however: you don't have any more work to do. No syncing of throttle bodies for a 990 engine. Under chapter 8 they have it broken down in to carbed and FI systems. Under the carb section it has a heading "Synchronizing the carburetor" and there is no matching section under the FI part. Nothing that even comes close.
    #5
  6. pdxmotorhead

    pdxmotorhead Been here awhile

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    On most multi throttle body applications that I've fiddled with, the throttle bodies are sync'd by measuring the gap between the lower side of the throttle plate and the wall of the TB.. Both should have the same gap with no pressure on the throttle, and the same distance from the leading edge to the TB wall at WOT.. The only time they may need sync is if somehow the linkage is damaged or disassembled beyond obvious need..

    2 cents..
    Dave
    #6
  7. Pistolero

    Pistolero W. F. O.

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    Well I have been trying to find where someone has done it to a 990 adventure and there are a few mentions of it on this forum but on a couple superduke forums they talked about it at some length and it was same process as on the 950 as far as using a manometer. Just hook it up to the nipples from the SAS and measure like you would on any other bike from a vstrom to an FZ-1. It has an adjuster screw just like the 950 on the rear left of the linkage between the two butterfly valves.

    I don't see how it would not be adjustable because as I understand it... And again not the sharpest shed in the crayon box here... But as the cylinders wear in they use an ever so slightly different amount of air and need adjusting to compensate or it can result in one cylinder "dragging" the other and can cause anything from rough idle to ,in extreme cases, rough running, vibration, and stalling at idle.

    Some of the 990 SD guys even said it helped the infamous 4000-4500 flat spot that they have. Now, i don't know about that. But it seems like it would make more of a difference at idle obviously.

    I'm going to call the dealer in Atlanta today to see what I can find out. Unfortunately the experiences I have had with the dealer here have been rather terrible....

    I'll report back my findings ASAP and will continue researching the subject.
    #7
  8. JTXT

    JTXT Adventurer

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    You can use Tune ECU instead of a manaometer to synch the throttle bodies on a 990.

    The bike's ECU controls the idle speed.
    #8
  9. fast4d

    fast4d Long timer

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    EFI bikes have map sensor on each TB so you can sync if you hook up using tuneECU, etc.

    I never found it necessary to sync my superduke after 37k miles. on my rotax aprilia it helped.

    on the carbed bikes wouldn't you need sync gauges (pro or home made)? you sync the rear cylinder to match front.
    #9
  10. Hipster

    Hipster Long timer

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  11. Pistolero

    Pistolero W. F. O.

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    Basically just check it with the tune ecu instead of the manometer and adjust the screw accordingly? I assume there is a screen in there that shows the MAP sensor pressure when the bike is running.

    I have yet to get tune ecu. Sorry for my dumb questions.
    #11
  12. ElRod

    ElRod 4

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    Yes and yes.

    I'd also follow the hose back from the MAP sensors to the brass fittings that screw into the intake runners to remove and clean before adjusting.
    #12
  13. Pistolero

    Pistolero W. F. O.

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    Thank you very much!

    That's good news, I don't have to drop a hundred bucks on a gauge. I have noticed a bit of dry rotting on my MAP sensor hoses so I may just replace the hoses all together. Great tip on cleaning everything first.

    I was planning on re-mapping anyhow since I'm switching back to the factory air box (from CPR)...

    Thanks again for the helpful info.
    #13
  14. Pistolero

    Pistolero W. F. O.

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    Yeah a few times as a matter of fact (not my 990). All three times I have received a misdiagnosis and ended up spending more money than I had to. Admittedly that was in 2008-2009 and I have since started doing my own work (ALWAYS the best option) unless you are rich.... Of course I guess I have to thank them because they ultimately inspired me to do my own work.

    Sorry to have offended you since you obviously work there... Who is it that I trust to ask questions about my bike and who is it I trust with balancing my wheels and tires?.... Oh yeah... You... What's the problem... Furthermore, I never mentioned any names. You assume you know what I'm talking about.

    And no my girlfriend does not work in service.

    I'm not exactly the only person with this opinion but since this has nothing to do with the topic, that's enough of that.
    #14
  15. ElRod

    ElRod 4

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    Why are you ditching the CPR?
    #15
  16. Pistolero

    Pistolero W. F. O.

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    It was not bad but I have one with the older plate design. They don't hold up too well and I liked the way it ran before. I gained a few horsepower but lost a bit of torque and unfortunately when I got it dyno tuned the guy accidentally brought back my snatchy throttle problems. It ran well before and I'm just going to tweak it from there. Try a few maps and see what I like best. Maybe try a power commander later on down the road. I'll probably send the plate back to them and they will send me a new one. (This as actually the second plate). They are a pleasure to deal with. The new ones are great and I may put it back on sometime. The owner of the company is awesome and I would still recommend the intake. They have the issues sorted now.
    #16