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Thread: Dorsoduro 750 then?

  1. #16
    apriliaforum prov-nov fabiostar's Avatar
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    a rear tyre is needed sooner rather than later, my other pair run Avon 3d ultra,s which i have to say i really like so maybe another one of those tho i am tempted to try a road 4 or 5 on it cause anything iv heard about them is good
    the older i get,the faster i was

  2. #17
    apriliaforum prov-nov fabiostar's Avatar
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    Fat duck? i assume its not a feathered duck thats eaten to much? i come from bikes that dont have such white mans magic lol... so what are they? how easy to put on and are they needed or am i playing with fire, il be getting my bike on saturday so i will check if i have a duck thats fat already fitted,,,, i just have to work out what il be looking for?
    the older i get,the faster i was

  3. #18
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    The FatDuc was originally developed to help with the lean running of Ducatis (hence the name) under feedback from the O2 sensor - it's a classic O2 hack, basically, and has been adapted to many many models.
    There are numerous "copies", Motocorsaro is one specifically for our bikes, might be easier to get hold of - there's a whole thread for it.

    In essence, it makes the ECU think the engine is running too lean, which richens the fuel mix up a bit, so the bike consequently runs more smoothly at part throttle and low engine speed. It is adjustable to your liking.
    2009 Shiver (White) | UK

  4. #19
    apriliaforum Junkie joelbo's Avatar
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    Odds are good the previous owner installed it already as they're really jerky at low speeds without it. I ordered one without checking first, then saw it already had one when I went to install it. It just needed to be adjusted as it was essentially turned off. It makes a world of difference especially if you do a lot of city riding! It's worth every penny and surprisingly improves your fuel economy!

    Sent from my LG-H812 using Tapatalk

  5. #20
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    Quote Originally Posted by joelbo View Post
    Odds are good the previous owner installed it already as they're really jerky at low speeds without it. I ordered one without checking first, then saw it already had one when I went to install it. It just needed to be adjusted as it was essentially turned off. It makes a world of difference especially if you do a lot of city riding! It's worth every penny and surprisingly improves your fuel economy!

    Sent from my LG-H812 using Tapatalk
    it doesn't help your fuel economy.. remember it's tricking the CPU including the estimatedmpg
    Don't be a jerk... jerk

    2016 KTM 250 xc
    2013 KTM 350 xcf ---------------SOLD
    2011 Husqvarna 630 ------------SOLD
    2007 KTM Superduke 990-------SOLD
    2009 Dorsoduro 750
    2003 KLX 400R
    2009 YZ450 -----------------------SOLD
    2007 ZZR600 ----------------------SOLD
    2006 CBR600RR ------------------SOLD
    2009 Ninja 250 -------------------SOLD

  6. #21
    apriliaforum Junkie joelbo's Avatar
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    Quote Originally Posted by RadicalTireSkid View Post
    it doesn't help your fuel economy.. remember it's tricking the CPU including the estimatedmpg
    It says in the AF1 description for it that it improves fuel economy... Is that not the case?

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  7. #22
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    Quote Originally Posted by joelbo View Post
    It says in the AF1 description for it that it improves fuel economy... Is that not the case?

    Sent from my LG-H812 using Tapatalk
    I could be wrong but the logic doesn't make sense in my brain. Tricking the ECU to "ADD" fuel. That usually means increasing fuel consumption.

    The dash readout says higher fuel economy, but I get the same range or less.

    It's possible that fuel isn't added and the airflow is just restricted instead... but that would just net an equal fuel consumption.
    Don't be a jerk... jerk

    2016 KTM 250 xc
    2013 KTM 350 xcf ---------------SOLD
    2011 Husqvarna 630 ------------SOLD
    2007 KTM Superduke 990-------SOLD
    2009 Dorsoduro 750
    2003 KLX 400R
    2009 YZ450 -----------------------SOLD
    2007 ZZR600 ----------------------SOLD
    2006 CBR600RR ------------------SOLD
    2009 Ninja 250 -------------------SOLD

  8. #23
    apriliaforum Junkie joelbo's Avatar
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    Quote Originally Posted by RadicalTireSkid View Post
    I could be wrong but the logic doesn't make sense in my brain. Tricking the ECU to "ADD" fuel. That usually means increasing fuel consumption.

    The dash readout says higher fuel economy, but I get the same range or less.

    It's possible that fuel isn't added and the airflow is just restricted instead... but that would just net an equal fuel consumption.
    This is the explanation from AF1:

    "FatDuc is a means of richening the part throttle fuel mixture on certain Aprilia/Moto Guzzi/Vespa models specifically the Aprilia Shiver and Dorsoduro 750/1200. This unit fits all models listed above, but extensive, successful testing has been carried out only on the Shiver and Dorsoduro 750/1200 models.

    The reason your bike suffers from poor fuel economy and throttle response is emissions mandated lean fueling, also the cause of the extreme heat coming from the exhaust system and very hot running in town, this device SIMPLY plugs inline with the stock oxygen sensor and allows a small reduction in the voltage of the return signal to the ECU, which richens the mixture. This results in improved throttle response, fuel economy (I know this seems contradictory) and smoother running at cruise.

    There is NO full throttle power gain to be expected since it does not alter wide open throttle fueling. The difference when riding the bike however is night and day, AND the device is adjustable.

    You CANNOT make the motor run leaner with this mod anywhere in the rpm range but it is adjustable from an effective zero change from stock to very rich, we recommend you try the "as delivered” setting on the trip screw first and make only very small adjustments from there."

    Sent from my LG-H812 using Tapatalk

  9. #24
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    The lean stumble this device is meant to cure is when fuel is not burned in the cylinder. Fuel that's injected but not pushing the bike forward is not going to help your economy. In response, you have to average a larger throttle opening to maintain a given speed. Hence, higher fuel usage. With a richer mix (not "rich", simply richer than "too lean"), it burns more fuel more of the time, and you get the benefit of more tractive effort for less fuel injected - better economy.

    The computer's MPG figure is calculated from the injector duty cycle, not the O2 sensor.

    Tricking the O2 sensor isn't the best way to cure the fueling, a remap is, but the hack is way cheaper for sure.
    2009 Shiver (White) | UK

  10. #25
    apriliaforum prov-nov fabiostar's Avatar
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    cheers for the answers , il will have to have a look and see if i can see one fitted to mine, other than in sport mode it feels wild sharp, the other two settings it seems to be runing fine.
    i have noticed that it take a few stabs of the starter motor to fire it from cold? its spinning over plenty fast enough but it just seems to like a few goes.

    new rear tyre, a Road 5 has transformed the bike aswell. loving it so far
    the older i get,the faster i was

  11. #26
    apriliaforum Junkie joelbo's Avatar
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    Quote Originally Posted by fabiostar View Post
    cheers for the answers , il will have to have a look and see if i can see one fitted to mine, other than in sport mode it feels wild sharp, the other two settings it seems to be runing fine.
    i have noticed that it take a few stabs of the starter motor to fire it from cold? its spinning over plenty fast enough but it just seems to like a few goes.

    new rear tyre, a Road 5 has transformed the bike aswell. loving it so far
    Now, I know this sounds ridiculous but a few of us have had far better luck starting it right away by applying the rear brake while starting. Couldn't hurt to try.

    Sent from my LG-H812 using Tapatalk

  12. #27
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    Be sure you are waiting for the fuel pump to prime and the relays to stop clicking before attempting to start. I wait for the clocks' fanfare to die down, personally, as I used to get the occasional reluctance.

    The ECU does a little self check of the throttle bodies, indicated by the brake light coming on and off (accompanied by the dedicated relay clicking). You can start the bike before it completes this, and it goes by the old calibration. But every once in a while (something like 1 in 20 key cycles), the ECU says no and forces the check - preventing the bike from actually firing (it will crank).

    If it's showing this reluctance every time, though, it's probably not this.


    And it could be any number of things. The bike seem to want really good oompf from the battery / starter motor to actually fire, so it might crank well, but if it's not "well enough", it won't go. There's a few places to look, but start with terminals - i.e. battery and the starter motor itself (these are known to corrode). If these are clean and whatnot, then look at relays.

    It could also be the MAP sensors, as they're used to figure out what stroke the engine is on and time the ignition and injection accordingly - before firing. At least, this must be how it's done because the bike can't be "twingled" (rephasing one set of cams 360° causes one of the cylinders not to fire at all until warmed up - i.e. wrong fuel phasing) and there is no cam position sensor or similar.


    Alternatively, I like the Biff Tannen approach.
    2009 Shiver (White) | UK

  13. #28
    apriliaforum prov-nov fabiostar's Avatar
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    well starting wise. i cleaned the starter motor terminal that was a bit iffy looking. and iv let it go through its clock checks and its firing the very best.

    so i went out today with some friends round the local twisties to the coast, can i just say, i wish id bought one of these bikes bloody years ago... its a total riot, the right amount of engine in the right amount of chassis....
    the older i get,the faster i was

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