2005 KTM 950 ADV stall, backfire, sputter issue

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

  1. teambft

    teambft teambft

    Joined:
    Feb 19, 2009
    Oddometer:
    1,198
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    Brentwood, TN
    My third 9xx KTM. Here are the vitals:

    Just bought it about two weeks ago.
    12,100 miles - appears to be very unmolested
    Performed OC Wisdom SAS/cannisterectomy removal
    Installed D&D pipes
    Rejetted carb with Pro Factory kit
    Installed sportingwood's intake and ITG foam filter; this removes airbox entirely
    Bike ridden between 600 and 2000 ft
    Performed flappendectomy

    Rode it last night for first decent distance. Prior, just starting and running around neighborhood - in which it was running very nice. Although it does seem it should pull a little harder from the bottom (stock gearing).

    So last night, rode it to downtown Nashville - it was about 94 degrees heading down. Gas could be a little old in it - prior owner rode bike maybe 1,000 miles in 15 months.

    For first 15-20 minutes of the ride, performed great.
    Then, it began sputtering, hesitating. Oil temperature held at 4 bars most of the ride, 5 when sitting at stop light.
    I was required to rev RPMs to keep it going....then it died. Did backfire a few times - from what I recall, did so on decell. Bike seemed to be starving for fuel.

    Please provide some direction and advice - thanks a ton!!


    I plan to re-check my venting and hoses. Sparkplug wires, battery connections, etc. to start. I've read about the ignition switch contacts.

    Fuel pump?? I've researched the vacuum pump to replace the stock electronic. Just ordered from Alternate Cycle. Not sure if thats the issue at hand, but liked the idea.
    #1
  2. Orangecicle

    Orangecicle On a "Quest"

    Joined:
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    My bike came with the Factory Pro setup. It sucked at 850' elevation and stock paper filter with no prefilter. That setup makes the bike way, way rich. I spent a long time working on it and and a lot of money on the dyno to figure out that the 45 idle jets just won't work. Pyndon convinced me to go out and buy the stock 42 idle jets (I didn't have them) and to start bringing down the jetting. My bike jetting is now fairly close to stock, and it runs perfectly. Current setup:

    Idle jets: stock 42s
    Float height: stock 3mm
    Needles: Factory Pro titanium (stock needles are expensive, so I keep these), stock position at second slot from the end. Might move to the middle position the next time I'm in there.
    Main jets: 162, 168 (slightly above stock because I run 990R cams and aftermarket exhaust)
    IMS screws: FlexJet 2s out 2 turns

    I ride the bike at my elevation and also take it to Denver to ride in the mountains. Therefore, having the bike slightly on the lean side is perfectly fine for me. I would guess that my bike is just about perfect on jetting or very slightly lean, so this is the perfect setup.

    You can go to the larger jetting to try and make the most power possible out of the bike. However, this is just inconsistent with how the bike was designed to be set up. I do not agree with the Factory Pro people on this point at all. I want a bike that runs and idles well. I don't think you can get that out of the F.P. setup. FWIW.
    #2
  3. Gustavo.Ramos

    Gustavo.Ramos Been here awhile

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    Check if one of the diaphragm rubbers isn't ripped, or one of the intakes boots isn't leaking air inside.
    #3
  4. Sporting Wood

    Sporting Wood I

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    Oct 18, 2011
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    897
    Location:
    Horneytown, NC
    I've ridden to 14,000 feet, get great power and 40+ mpg out of my Factory Pro jetting. I as well had the same problems you had but later realized the importance of adjusting the float height. Their instructions don't make it so clear and I have found that everyone that's come into my shop with the same complaint didn't lean out the floats. :freaky


    I'm guessing the problem here is fuel pump, some trash in the jets, or an air leak.
    #4
  5. Sumi

    Sumi Long timer

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    Fp?
    #5
  6. teambft

    teambft teambft

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    Thanks all!!!!!!!!!

    Too embarrassed to even say this....but my initial re-teardown has led me to believe I didnt have the carbs all the way down and in their boots. Will get the tank off tonight and confirm.

    ARRRRGH - and I've been riding and wrenching bikes for....hmm over 30 years
    #6
  7. a.c.s.

    a.c.s. Complaining less

    Joined:
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    Did you check that there's enough gas in the tank?

    I ran mine dry when I bought it and had the same problems. The idiot light never indicated low fuel... That makes me an idiot. Didn't realize it until I went to pull the tanks to check out the carbs and the tanks felt very light.

    -An Idiot...
    #7
  8. TLtrials

    TLtrials Been here awhile

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    NW North Carolina
    The symptoms sound like it is sucking air. That is where I would check first you are likely right that a carb has come loose.

    There are two clamps for each carb, make sure they are both seated and clamped.
    #8
  9. Sporting Wood

    Sporting Wood I

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    Happens! Be gentle with the hose clamps, they will strip if you look at them too hard. Back when they raced these things in the Paris Dakar, those guys safety tied the boots.
    #9
  10. teambft

    teambft teambft

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    Well, tightened the carbs down to the boots. Rode her tonight and it started again with the same symptoms. Thanks for all the advice - will keep digging.
    #10
  11. kamanya

    kamanya Andrew to most

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    Is there a fuel filter in the line somewhere?
    #11
  12. teambft

    teambft teambft

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    Thanks.......will add that to my list.....
    #12
  13. homerj

    homerj 742 Evergreen Terrace

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    Check your ignition switch. I had the exact same issue and thought it was Mexican gas that was causing it. If the problem is more or less constant look in the HOW for the hotwiring tip, set up the wires ahead of time and install it when it starts. if the issue disappears and never recurs it's the switch.

    it's an outside possibility, but the ease of testing would put it at the top of my t-shoot list.
    #13
  14. teambft

    teambft teambft

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    Thanks!! Thats on my list as well - read about it in one of the forums.
    #14
  15. Sporting Wood

    Sporting Wood I

    Joined:
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    Oddometer:
    897
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    Horneytown, NC

    Are your tanks full? As long as fuel is above carb level it'll feed the carbs. This is a quick way to tell if you have a bad fuel pump... I'm on my 3rd one.

    Unless you added a fuel filter, there isn't one on there from the factory besides the strainer screens on the petcocks. Otherwise a plugged up one can cause this.

    Since you rejetted, it could be something has gone awry in the carbs. Remote possibilities could be a leaking diaphragm, sticking float needle, overly lean adjusted float.... but these just don't seem likely to me.

    Could also be sucking air from one of the smog gear holes in the intakes.

    My money's on fuel pump:freaky. Hope you get it worked out so you can go ride that thing.
    #15
  16. teambft

    teambft teambft

    Joined:
    Feb 19, 2009
    Oddometer:
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    Location:
    Brentwood, TN
    Current List:

    • Performed OC Wisdom SAS/cannisterectomy removal
    • Installed D&D pipes
    • Rejetted carb with Pro Factory kit
    • Installed sportingwood's intake and ITG foam filter; this removes airbox entirely
    • Performed flappendectomy
    • Installed Alternate Cycle vacuum fuel pump - using one of the right manifold outlets to run the vacuum pump.
    • Richened half a turn - should be about 1.75-2.0 IMS turns out at this point - will confirm
    • Coil/spark plug wires are seated all the way down
    • Used Flowmeter to check synch on carbs
    • TPS output is about .53 volts
    • Still running crappy - hanging idle (lean?) but hangs longer than what a lean condition would indicate after blipping the throttle.
    • Coughing last night - when throttle twisted, bogged down badly.
    • Still seems to me its an air leak someplace.
    • Gonna tear into it again tonight and check all hoses, carb boots again, carb diaphragms, remove jets and clean carb again, etc.

    I also noticed that when I installed the slow jets, they dont screw into the carbs all the way - still a little threads showing. Is this normal? I've never seen this on other carbs I've jetted and I cant recall if the stock jets were all the way in. I will compare the sizes to my stock jets to ensure Factory Pro sent the right ones.

    Anyhow.....will keep workin on her.....anyone has any input, please keep sharing!!! Thanks!!
    #16
  17. stoned32

    stoned32 n00b

    Joined:
    Jul 22, 2013
    Oddometer:
    1
    I have the same problem and i can't find the solution... Help please
    #17
  18. ABuck99

    ABuck99 0.0

    Joined:
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    Location:
    Georgia
    Post up a few more details on the FP jetting: ( that will help us give you more confusing opinions:lol3)

    Which mains
    Which pilots
    Where did you set float height
    FP needles? Which clip position
    Tank venting- how did you route you gas tank vents?
    Carb venting- did you run separately or still have the y connection
    Are the hoses used to sync your carbs closed off/capped

    Unless you are using stock pilots-needles and near stock mains, your fuel screws are likely set too rich. And like Chris mentioned float height makes a big difference, and it's tricky getting it set right.

    I suspect that alternate cycle vacuum fuel pump, may also be presenting some issues. So many factors to influence vacuum performance- mounting position as well.

    #18
  19. Sumi

    Sumi Long timer

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    Did you happen to solve this problem?
    #19