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Thread: sr50 70cc kit what size jet

  1. #1
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    sr50 70cc kit what size jet

    Has some one done a 70cc kit on sr50 what sise jet u using im up to a 100 and still running Hot

  2. #2
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    the jets go about 76 to 84-86 everything else is of the chart tuning wise

    i use a 82 jet on a 70cc kit and it dosnt overheat, also you need to tune the airbox and other parts to run propperly

    also bleed the air from the pump and cylinder

  3. #3
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    Thanks for reply running standard air Box what filter other mods do you recommend thanks for your help rgrs tony

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    what engine and setup are you running?

  5. #5
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    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

    put a 96 jet in carb starts rides ok tried a 103 will not run tried 100 runs rides not as good as 96 but still hot 1/2 turns on air screw needle in midle position plug brown but seems hot, exhaust muffler too hot to touch is this normal as not run in yet

    6.3 gram rollers red clutch spring

  6. #6
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    try colder heat range sparkplug such as 9.what ratio are u premix? too much oil makes mixture lean so watch out.For this cyl u can easy use the stock oil pump.just adjust the lever a bit.When u test the color make a long trip.Some plugs doesnt show direct proper reading.

  7. #7
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    yes ive switched back to pump and noticed different plugs are making it run hotter do you recommend air filter up grade a running on original is what best one to use if so cheers Tony

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    Thumbs up

    Thanks great post

  9. #9
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    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
    86 bogging down
    92 bogging down
    98 bogging down
    102 wont run on this jet
    any idea just wont run on this filter



  10. #10
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    how have you tuned your airbox

  11. #11
    apriliaforum Junkie jixaw's Avatar
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    just a suggestion...but have you looked into getting a Doppler filter? i have a couple of the regular ones and one alien eye....the regular ones come with a 17.5mm tube and a 19mm tube....i bet the 17.5 tube would match your carb perfect..if not then the 19mm tube with a slight upjet
    2004 Aprilia Mojito Custom 50cc - 65cc Airsal BBK, 17.5 Delltoro PHVA w/echoke, vforce reed cage, Doppler filter, Leo Vince Touring exhaust, Malossi Multivar, Naraku 4000 rpm clutch
    2004 Aprilia Mojito Retro 50cc - 70cc DR BBK ported/polished along w/cases, balanced crank ,19mm PHBG carb, Topperf reed cage, oil pump delete, Polini boost bottle, Doppler Alien eye filter, Motoforce rear shock, Mojito 125 front fork shocks, Turbokit Exhaust, Topperf variator, Malossi Delta clutch, Pirelli SL60 tires and much much more
    2003 Vespa ET2 50cc
    2001 Triumph TT600

  12. #12
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    Just use piaggio stock airbox with foam filter.Brand doesnt matter.Mainjet around 80-88 bigger no need it.

  13. #13
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    great thanks I have left brass washer out off back of carb with holes in it is that correct or does it have to be left in

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  15. #15
    apriliaforum Junkie jixaw's Avatar
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    did you have any luck going back to the oem airbox?
    2004 Aprilia Mojito Custom 50cc - 65cc Airsal BBK, 17.5 Delltoro PHVA w/echoke, vforce reed cage, Doppler filter, Leo Vince Touring exhaust, Malossi Multivar, Naraku 4000 rpm clutch
    2004 Aprilia Mojito Retro 50cc - 70cc DR BBK ported/polished along w/cases, balanced crank ,19mm PHBG carb, Topperf reed cage, oil pump delete, Polini boost bottle, Doppler Alien eye filter, Motoforce rear shock, Mojito 125 front fork shocks, Turbokit Exhaust, Topperf variator, Malossi Delta clutch, Pirelli SL60 tires and much much more
    2003 Vespa ET2 50cc
    2001 Triumph TT600

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