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Will Rapidbike Evo Ecu Work On A Big Bore?

Discussion in 'Technical / Mechanical Discussion' started by Hildero, Aug 27, 2020.

  1. Hildero

    Hildero New Member

    Current Bike (Optional):
    Yzf R125 2015
    License Currently Held:
    UK Provisional (CBT)
    Hello everyone, So I was wondering if I can use the RapidBike EVO fuel controller with my malossi big bore kit on my R125. This ECU has auto-tune available. Will it automatically sort out the fuelling on a big bore kit? 125 to 182cc cylinder. Will I need to dyno it? Or will it auto-adjust the fuelling by itself? Or it won't work at all? Looking forward for an answer. Many thanks.
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  3. misiozol

    misiozol Active Member

    For this you need to understood how autotune works, and it works by reading data from lambda sensor so if ur bike dont have one there is NO option of proper autotune or for that mater any auto tune. In case having lambda zirconia sensor 0-1V autotune is very limited due to afr 14.7:1 so no power tune or any other than this. If you want proper autotune you need ecu with wideband lambda input ! everything else is expensive toys.
    NorthCust likes this.
  4. NorthCust

    NorthCust Active Member

    Home Page:
    Current Bike (Optional):
    2008 Yamaha R125, Gasgas TXT 280, Stretched Neos
    License Currently Held:
    UK Full Bike
    ^^ what he said
  5. Hildero

    Hildero New Member

    Current Bike (Optional):
    Yzf R125 2015
    License Currently Held:
    UK Provisional (CBT)
    Guys could you please help me find a solution to a problem? Basically as soon as you start the bike it runs well idle for 3 seconds and then it srarts running poop. At a diagnostic centre "emission test centre" they adjusted the AFR and it didnt fix the problem. How can I make the bike work on open loop mode and not closed loop mode as it is now? Because I think the Stock ECU messes with the Malossi forcemaster fuel controller. The bikes runs poop and hot on low - mid rpm and its not adjustable. The more you increase the fuelling on low mid rpm ranges the more lean it runs. Its currently running on stock 125 injection at low-mid and 180 cc at high. Please help me out. Will getting a piggyback fuel controller with a lambda reader solve the issue? Like a rapidbike EVO ecu that monitors the lambda readings? I beg you help me solve this. I cant get the bike to work like it should.
  6. NorthCust

    NorthCust Active Member

    Home Page:
    Current Bike (Optional):
    2008 Yamaha R125, Gasgas TXT 280, Stretched Neos
    License Currently Held:
    UK Full Bike
    hey,

    As per the other topic I think the solution is, as it was, get a rabbit or similar ECU with a wideband, and get rid fot he current ecu + narrowband altogether.

    Trying to play cat and mouse when there's a narrowband in the mix is always gonna bring you back to stoich (if you're lucky).

    I offered to help look into/collab this as I'm looking to do the same for different reasons, but I've just forked out for a new cylinder and stuff for my other motor so won't be buying right away. Hopefully soon tho bc I'd like to have the new motor built in the next week or two.

    >> Will getting a piggyback fuel controller with a lambda reader solve the issue?

    pretty sure the answer to that is still: no (for all the same reasons as before).

    If you haven't yet tried running it with the lambda sensor unplugged, personally I'd be inclined to give it a go. It'll probably be rubbish and you'll have engine lights and stuff, plus as Misiozol said it'll revert to a very coservative map (the opposite of performance) but it may be slightly less sh!tty than the current situation.

    Even if you put a 140cc injector in but I don't see how it would be any different from the current situation, your narrowband is still gonna aim for stoich so it's not gonna fool anyone.

    I guess the only other thing might be to try to fool the narrowband into thinking it's running weak.. like leave it connected but in fresh air or something, or make a collar which introduces air to fudge the readings but that seems very hacky, is unlikely to run well, and alsoseems pretty "mot-faily"

    imho Misiozol is right, sorry. Custom ECU (e.g. rabbit)

    On the upside whilst it sounds scary the custom ecu is really no different from fitting a PCV/PCFC or Forcemaster, just has a bit more wiring and more options.
  7. misiozol

    misiozol Active Member

    There is not much more to be added > buy custom ecu with wide band support <

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