950 SE bogs after hard hits/jumps

Discussion in 'Crazy-Awesome almost Dakar racers (950/990cc)' started by CC Ryder, Apr 9, 2019.

  1. CC Ryder

    CC Ryder Adventurer

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    I know someone will say "search, its all in here".

    I'm a newish owner to a 2008 950 SE.. a low mile puff as it were.. until it met me.

    It has the Rottweiler setup, and it runs and pulls like a boss.. gobs of power..

    When I'm running it on the road, dirt roads, two track.. It runs perfect. But when, I get into rough stuff and i'm charging whoops, bumps, jumps, it will occasionally bog or stumble.. This could be potentially dangerous. I haven't touched the carbs at all since I've bought it.. Haven't really done anything to it.. other than wring its neck out. A friend mentioned that it is likely the float levels that are the issue. Is this the path I should be going down? Any insight is appreciated. Thanks gang.
    #1
  2. Maoule

    Maoule Long timer Supporter

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    Bypass your kickstand switch.
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  3. GezwindeSpoed

    GezwindeSpoed Been here awhile

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    Side stand is a good one. Another one can be the your fuel pump is delivering too high pressure flooding engine on bumps. So check if you have the original pump or an alternative.
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  4. Boatman

    Boatman Membership has it's privileges ;-) Supporter

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    Another vote for the side stand switch.
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  5. johnno950

    johnno950 Long timer

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    Mine did same as yours ccryder,cough splutter etc etc sometimes when ride over rough ground.
    It had me stumped and checked same as other have said regarding side stand switch,i checked out the few other thing also but found the float level on the rear carby was a mile out,was my mistake
    as i had bent the float plate while fitting jets,re adjusted float level and its been sweet ever since.
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  6. CC Ryder

    CC Ryder Adventurer

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    I should have noted that in my post.. Bypassing the kickstand switch was the first thing I did when I bought it. Been through that one already on my 990.

    I did install a "facet" fuel pump in it, as I had read the original was not reliable.

    I did some reading last night in various carb threads and it seems most point to float levels or fuel pressure.. as you guys suggest. It seems some were not able to resolve this issue.. I have a hard time believing it can't be fixed. Hopefully, this weekend I can make progress on it.

    Thanks everyone.
    #6
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  7. Yellow Pig

    Yellow Pig Allergic to asphalt! Supporter

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    Its the CV carbs. They are vacuum operated, so big hits make the carb slides drop.
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  8. AdvRonski

    AdvRonski They call me......Ronski

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    It's not the CV carbs. Well, not directly. They were designed to operate with gravity feed fuel pressure, but the 950 fuel tank design requires a fuel pump to deliver fuel. Install a fuel pressure regulator, set it to 1-1.5 psi, and hit as many g-outs, whoops and jumps as you want, without any more bogging.
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  9. GezwindeSpoed

    GezwindeSpoed Been here awhile

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    I had an aftermarket fuel pump (designed for oldtimer cars). I had a lot of flooding problems on bumps and stones (in Albania); fuel smell on breaks. I bought a original fuel pump on ebay and all problems were gone after I installed it.
    #9
  10. buzybraza

    buzybraza Been here awhile

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  11. CC Ryder

    CC Ryder Adventurer

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    Just getting back from Moab with the SE.. Some of the time it ran flawlessly in the rough stuff.. other times I was cursing it. Thanks for the replies gentlemen. The bike had the original fuel pump installed when I bought it.. but also included the "facet" pump, which I installed after reading of countless failures with oe pump.. can you recommend a fuel regulator that works well.. and where to buy?

    The kickstand has the BD reinforcement bracket installed. Thanks.
    #11
  12. bigborett

    bigborett Hipster

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    Had a similar problem with mine when I bought it.
    It had an aftermarket fuel pump fitted that was pumping out about 4.5 psi, way to much. Would blow past the needle and seat on g-outs or some rough ground.
    Even the facet runs at a higher pressure than the standard pump, about 2psi I think.

    Have since gone the vacuum pump route. A little setting up but seems good now.
    Have still run a bypass on the vacuum pump to regulate pressure though.
    #12
  13. GezwindeSpoed

    GezwindeSpoed Been here awhile

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    I would return to the oem pump with dr Bean kit.
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  14. Boatman

    Boatman Membership has it's privileges ;-) Supporter

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    Yup.

    Personally I think the OEM pump failure is overrated. 200,000 plus miles on OEM pumps and have only have one true failure.

    And FWIW.... I still run the points.
    #14
  15. AdvRonski

    AdvRonski They call me......Ronski

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    So, I think the varied experiences with this type of carb flooding are directly related to the kind of riding one does. Here in Western Colorado, I ride mostly on rough, whooped out single and double-track, that would cause flooding even with the stock fuel pump. When I bought a replacement bike for my crashed 950, one of the first rides I went on had the bike loading up and stalling through the deep whoops, until I installed the fuel pressure regulator from the old bike.

    I used the Holley 12-804- https://www.amazon.com/Holley-HOL-1...17HWT0EZWB7&psc=1&refRID=9JB42AC7Y17HWT0EZWB7
    which I have set to 1 psi, and has been on the bike since 2010.
    #15
  16. usgser

    usgser Long timer

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    Mind you, I'm not a KTM guy so not remotely familiar with your 08. According to your conditions when issue occurs my first suspect would be worn sloppy float system. Get's hung up/bound on hard jolts allowing carb floading and settles back to normal eventually after further vibration/settling? 11 years old with unknown mileage/maint history... May just be time to thoroughly clean the carbs or rebuild them?
    #16
  17. nk14zp

    nk14zp Long timer

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    I would check fuel psi,floats and if that didn't fix it look at the harness around the neck.
    #17
  18. Whodatschrome

    Whodatschrome Long timer

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    This is interesting...I just did a desert race a couple weeks ago on my '06 950A (with a side stand switch delete), and in the rough whooped out section (ok, pretty much the whole way was rough and whoopi), and my bike kept wanting to load up and stall out. I had a brand spankin' new OEM pump that I installed a Dr. Beans kit on (I saved the 30k mile old pump that just pooped out, and installed the brand new points from the new pump onto it, as a spare pump). I've never had an issue stalling before, but then again, I don't think I've been in that many bad whoops before. I'm now wondering if I should look into that Holly regulator. I rather not have extra stuff on my bike though.

    To figure out how to adjust the Holly regulator to 1psi, did you install an inline low pressure gauge or something?
    #18
  19. AdvRonski

    AdvRonski They call me......Ronski

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    Yes, I used a combo vacuum/fuel pressure gauge that I teed into the fuel line just to set the pressure, then removed the gauge. As I said, I ride a lot of whooped trails around here, and the regulator is a necessity for me.
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  20. COXR650L

    COXR650L Long timer

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    What Ronski said...... Either float level or fuel pressure regulator. My 950 is really sensative to fuel pressure
    #20