sr50 70cc big bore problem

Discussion in 'Scooter Tuning' started by tony 123, Jul 18, 2019.

  1. tony 123

    tony 123 New Member

    Messages:
    4
    Piaggio sr50
    Tehno gas exhaust not sure what model


    Piaggio NRG 50 Power DT AC 07-09 17.5mm Carburettor with Auto Choke
    70cc cast iron cylinder kit from Naraku for Piaggio


    Aprilia SR50 R 45° 28/35mm Racing Air Filter Red

    ticks over ok but when reved bogging down
    tried a 76 main jet bogging down
    82 bogging down
    92 bogging down
    98 bogging down
    102 wont run on this jet
    any idea just wont run on this filter
     
  2. scubabiker

    scubabiker NITROJUNKIE

    Messages:
    6,632
    You need to restrict the filter a bit somehow.
    This is why I tell people to use an airbox
     
    Pete132 likes this.
  3. Damjan

    Damjan Member

    Messages:
    82
    Rides:
    Baotian Falcon 50R
    Do u have the factory manifold ? Also 17,5mm doesnt work on open filter good.
     
  4. tony 123

    tony 123 New Member

    Messages:
    4
    yes was running better with air box but getting hot do I leave the brass washer in back of carb the one with holes in
     
  5. tony 123

    tony 123 New Member

    Messages:
    4
    Thanks for reply yes original manifold going to try a 80 jet and change crank seals and try orginal filter like you say as seems to be getting hot
     
  6. Damjan

    Damjan Member

    Messages:
    82
    Rides:
    Baotian Falcon 50R
    Open filter doesnt work on 17,5, if u want to use it get 19mm or 21mm phbg carb. Also remove the restrictor plate with the holes , and modify the airbox inlet diameter to 18mm and then jet it should be 65-85 somewhere.
     
    Pete132 and tony 123 like this.
  7. tony 123

    tony 123 New Member

    Messages:
    4
    im going to leave 17.5mm carb on so do you mean to leave brass washer out with holes in it and make inlet hole in air box bigger to 18mm
     
  8. Damjan

    Damjan Member

    Messages:
    82
    Rides:
    Baotian Falcon 50R
    WASHER OUT, and the intake tube that the AIRBOX takes air from in stock is 12mm i think make it 18mm inside diameter.
     

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