First Post - Lambretta V50 Special Question

Discussion in 'The Workshop' started by Frazzle, May 29, 2019.

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  1. Frazzle

    Frazzle New Member

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    3
    Hello,

    First post and not at all technical so apologies in advance. I bought a new auto, 4 stroke, 50CC Lambretta V50 Special back in December (https://www.lambrettauk.co.uk/model/Lambretta-V50-Special) for the short commute to work. I love it but it is dangerously slow - not currently getting above 28mph. Would obviously feel more comfortable if I could squeeze 35-40 out of it. I've found a local scooter service guy who has attempted to de-restrict it for me but despite changing a few parts (rollers etc.) is not able to crack it. It's still being restricted electronically and he is struggling to locate/identify/change the PCB. He's never seen this particularly model before (they are rare) and so would love to hear from anyone who has experience with derestricting one - or just someone familiar with the scooter.

    Any help greatly appreciated!
     
  2. milo2025

    milo2025 Trip to Trumpton

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    727
    Greetings Frazzie,
    Your scooter is restricted by the placement of a spacing washer in the drivetrain system, also known as the variator system. Removing this washer allows the scooter's variator system to operate at its full potential, increasing the scooter's acceleration and top speed.
    Remove the kickstand from the side of your scooter: Pull out the pin that attaches the kickstand to the side of the scooter. You may need to loosen the bolt at the end of the pin slightly before pulling it out.
    Open the variator system by first removing the plastic intake covering -- the covering is often fastened to the outside of the variator system with two or three bolts that can be removed using a socket wrench.
    Detach the metal lid from the variator system -- the lid is secured with six bolts around the outside of the variator case; three of these bolts are located on the top of the lid, and three are located on the bottom. Remove the bolts with a socket wrench, as you would the bolts holding a tire rim in place, by alternating between top right, bottom left, top middle, bottom middle, top left and bottom right.
    Secure the front pulley wheel with a strap wrench. Wrap the strap around the wheel and tighten it. Position the handle of the strap wrench under the rear pulley wheel, so that it will wedge underneath the wheel when you unscrew the bolt holding the front wheel in place.
    Loosen and remove the bolt holding the front pulley wheel in place, using a socket wrench, before taking the front pulley wheel out of the variator system.
    Take the washer off the front pulley rod -- the washer restricts the belt's access to the front pulley rod, preventing the scooter's drivetrain from operating at full potential, thus limiting its acceleration and top speed capabilities.
    Reassemble the variator system, the intake case and the kickstand.
    ( You can bypass steps 4 and 5 by using an impact wrench to remove the front pulley wheel.)
    Is yours in the burnt orange colour? It looks fantastic!
     
    Mark Emerson Trentham likes this.
  3. Frazzle

    Frazzle New Member

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    Hi Milo,

    Thanks for the reply. Pretty sure the guy has tried all the standard mechanical stuff with the spacing washers, variator system and rollers. As mentioned, he thinks it's something electronic to do with the PCB so I was hoping that someone might have some familiarity with having de-restricted this particular model. Yes, I have the orange one, it's a great colour!
     
  4. milo2025

    milo2025 Trip to Trumpton

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    727
    You could try calling Cambridge Lambretta (I'm from Cambridge and they are highly recommended) and they will probably give you some great advice http://www.lambretta.co.uk/
    Good luck!
     
  5. scubabiker

    scubabiker NITROJUNKIE

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    7,321
    What's a PCB?
    Is it EFI? (fuel injection)
     
  6. scubabiker

    scubabiker NITROJUNKIE

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    7,321
    Just looked, it is EFI
    You need to remap the ECU
    It's probably a Chinese made ecu the same as other 4t euro4 bikes.
     
    milo2025 likes this.
  7. Stevep

    Stevep Well-Known Member

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    5,895
  8. Frazzle

    Frazzle New Member

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    I just tried Cambridge Lambretta but the bloke there was not able to help as "they don't touch those, only the classics" (I could feel the disdain in his voice :)).

    Is re-mapping the ECU when you plug it into a computer and 'talk' to it? My scooter guy said this is what he's normally do but he couldn't find an obvious plug. He reckons if it was the 125 would be able to do this but no luck on the 50.
     
  9. Stevep

    Stevep Well-Known Member

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    It looks like the typical gy6 50cc honda clone.
    Should be possible to get an unrestricted CDI for it.
     
  10. milo2025

    milo2025 Trip to Trumpton

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  11. Yiddo

    Yiddo New Member

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    1
    Hi have you had any luck de-restricting as I’ve just got one and also find 28 mph dangerous thanks
     

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