1. Husqvarna Motorcycles Made In Sweden - About 1988 and older

Installing the ufo's

Discussion in 'Vintage Restoration Projects' started by Bigbill, Apr 8, 2017.

  1. Bigbill Husqvarna
    Pro Class

    Husqvarna Motorcycle:
    '83 250wr
    Other Motorcycles:
    0 right now
    Finally started installing the UFO's in my round slide mikuni carbs 44mm through 38mm. One note for my post I drill a hole through the UFO mounting screw and tap it 3mm x .05. I don't use the self tapping screw it comes with. I could use the self tapping screw but it's my preference to tap it and use the flat head metric screw. I doing my cr500/xc500 44mm carbs first.

    www.boltdepot.com for screws
    www.amazon.com for the tap and drill.
  2. Eurofreak Husqvarna
    AA Class

    Location:
    Western NY
    Husqvarna Motorcycle:
    1986 TE 510, 1982 CR250, 2008 WR250
    Other Motorcycles:
    70's Triumph , Bultaco , Maico, etc
    Pictures! Pictures! Have your kid take and post some if you're a Luddite.
    This is supposed to improve the bottom end carburetion?
    454x and justintendo like this.
  3. Bigbill Husqvarna
    Pro Class

    Husqvarna Motorcycle:
    '83 250wr
    Other Motorcycles:
    0 right now
    It improves the overall throttle response, the flow of gas into the reed cage. That wall in the rear of the throttle sleeve blocks the gas flow and sends it into the incoming flow. Pics soon.

    http://thunderproducts.com/shop/u-f-o-ultimate-flow-optimizer/

    I'm planning on installing one in every round slide mikuni carb. They also make the UFO for other brands of carbs.

    This is snowmobile technology that works in any round slide carb.

    Where you live the jetting may differ. But you must go smaller on the pilot due to the increase in gas flow. Give your old vintage gal the edge in performance. Every little bit adds up. It's 1 hp gain per 100 cc's that's 5 hp for a 500cc bike. New boyzeen reeds, add the ufo, spacer under the reed cage, Brappppp.
  4. justintendo klotz super techniplate junkie

    Location:
    mercer, pa/northwest pa
    Husqvarna Motorcycle:
    84 250,86 400,87 430,88 250,95 360
    Other Motorcycles:
    99 kawasaki zrx 1100
    5hp on a 500?
    i have no doubt they help on a mikuni, with that huge hollow spot underneath a vm slide. some carbs dont need a spacer as the slide is designed to not need it..
    [IMG]
    taper bored
    [IMG]
    notice the above slide is upside down, the bottom is clean with no disturbance.
    SteveJ likes this.
  5. grouty Auto Lover ...

    Location:
    South West UK
    Husqvarna Motorcycle:
    78 390WR, 78 390 AMX, 500 Humph
    Other Motorcycles:
    works 73 CCM 520, another 73 CCM520
    Mmmmm ..... Lectron ! (said with a Homer Simpson voice :) )
  6. Eurofreak Husqvarna
    AA Class

    Location:
    Western NY
    Husqvarna Motorcycle:
    1986 TE 510, 1982 CR250, 2008 WR250
    Other Motorcycles:
    70's Triumph , Bultaco , Maico, etc
    Thanks Bill-Does the 40mm Mikuni use the 3.5 UFO?
    Seems like a good idea.
  7. Bigbill Husqvarna
    Pro Class

    Husqvarna Motorcycle:
    '83 250wr
    Other Motorcycles:
    0 right now
    It says the 3.5 cut away piece in included. Once you rejet it's awesome.

    I installed a 40mm carb on a 390cr. I installed the UFO, the leaner needle jet, and rejeted it. She ran awesome. But lots of power.
  8. Eurofreak Husqvarna
    AA Class

    Location:
    Western NY
    Husqvarna Motorcycle:
    1986 TE 510, 1982 CR250, 2008 WR250
    Other Motorcycles:
    70's Triumph , Bultaco , Maico, etc
    Did they supply the needle jet with the kit?
  9. Joe Chod Husqvarna
    Pro Class

    Location:
    upstate NY
    no jets....they do recommend going to a half the size you been running pilot and also use of a 3.5 slide regardless what you have in.
  10. Bigbill Husqvarna
    Pro Class

    Husqvarna Motorcycle:
    '83 250wr
    Other Motorcycles:
    0 right now
    Example, my ported, 81 cr250 husky with the UFO if I remember correctly the pilot jet was a 30 or 35. It depends where you live and your mix ratio.