950SM Jet kit required?

Discussion in 'Crazy-Awesome almost Dakar racers (950/990cc)' started by 510danr, Feb 28, 2013.

  1. 510danr

    510danr Adventurer

    Joined:
    Nov 2, 2008
    Oddometer:
    20
    Location:
    Oakland, CA
    I've got a stock 950 SM. Aside from raising the needles, will it benefit from bigger main jets? Trying to decide if I need a jet kit.
    #1
  2. brents347

    brents347 Trusting my Cape...

    Joined:
    Mar 5, 2006
    Oddometer:
    4,391
    Location:
    Where the hell is Truckee, CA?
    NEED a jet-kit for where you are at sea-level, no. Would the bike benefit from it a little bit? Yes. In my opinion it would not be enough to talk about.

    But if you have done exhaust or air-filter or air-box mods, that is a different question and you would benefit from the jet-kit more then.
    #2
  3. mousitsas

    mousitsas Long timer

    Joined:
    Oct 10, 2008
    Oddometer:
    3,311
    Location:
    Athens, Greece
    With stock exhausts and filter leave the jetting stock.
    With filter/exhaust mods its a different story.
    #3
  4. Zuber

    Zuber Zoob

    Joined:
    Sep 28, 2004
    Oddometer:
    2,614
    Location:
    Main Street, Shedd, Oregon
    The Flex-Jet remote screws always make a difference.
    #4
  5. genghis9021

    genghis9021 Arak Connoisseur

    Joined:
    Jul 6, 2008
    Oddometer:
    239
    Location:
    Chiang Mai, Thailand & NORCAL
    +1
    #5
  6. Sporting Wood

    Sporting Wood I

    Joined:
    Oct 18, 2011
    Oddometer:
    902
    Location:
    Horneytown, NC
    Needle makes a HUGE difference. I wouldn't own one with out them.:deal

    I'm the guy that tested and tested and tested jets and these damn god forsaken CVR carbs to death. O2 sensor, dyno, every combination possible, seriously. The stock needle is an on/off switch. When you fatten up the fuel on top of the rev range, the stock needle will throw everything into oblivion. Thing will gag and cough when you twist the throttle big time. Only way to make them work is to keep the top lean...which sucks and isn't the way to do it.

    Flex jets are nice, especially if you move wildly in elevation. Not necessary though imho.
    #6
  7. aeronaut

    aeronaut Been here awhile

    Joined:
    Sep 22, 2008
    Oddometer:
    422
    Location:
    Central MD, USA
    Search for 'x-bike' jet settings for 950SM. Requires a filter, remove airbox triangle, new main jets (and possibly idle ..can't remember). Really wakes the bike up.

    EDIT, here you go:

    Front Main Jet: 170
    Rear Main Jet: 175
    Floats set to stock 3mm height
    Mixture screws set to 2.5 turns out
    Slide Needles set to 3rd notch.

    Vent hose lengths are critical too, the ends of the vent hose must be in clean, still air, otherwise you'll get surging. The above requires free flow filter and more importantly, removal of triangle access holes in the airbox.

    This gave me fantastic throttle response and great low-mid torque, with pull to redline.

    FYI, Once I dyno'd, I was a touch lean at low rpm low throttle opening, and opened idle mixture screws to 2.75 turns.
    #7
  8. gefr

    gefr Life is a trip

    Joined:
    Nov 26, 2005
    Oddometer:
    4,617
    Location:
    East Med, Greece
    I always worry about consumption, when I hear for more power. How did your settings affect consumption?
    Cheers.
    #8
  9. mousitsas

    mousitsas Long timer

    Joined:
    Oct 10, 2008
    Oddometer:
    3,311
    Location:
    Athens, Greece
    Is it possible to post your dyno+AFR chart? It would be much appreciated!
    In case you haven't got it, do you remember your AFR up top?
    #9
  10. nattyMo

    nattyMo Been here awhile

    Joined:
    Jun 3, 2007
    Oddometer:
    582
    Location:
    Baltimore Md
    As Aero has said the X-Bikes solution has worked well for many.

    Prior to learning of the X-Bikes jetting spec, I had mine re-jetted using a dyno AF etc. at a local shop that's done great work on some of my previous bikes. I wasn't trying for top end power, just great driveability. While I don't have specifics I can say that the needles did cause problems and the factory pro kit I provided didn't offer a solution. The shop spent a ton of time finding a needle that worked.

    For sure the jetting changes improved the ride, no more surging it pulls from idle to the limiter in one smooth surge. I picked up 11hp in the mid-range, it's making 98hp at the wheel. Mileage is in the 32-40 range, same as stock. I am happy with the results, it was worth the time and expense.

    NM
    #10