Strange looking intake

Discussion in 'Crazy-Awesome almost Dakar racers (950/990cc)' started by Gustavo.Ramos, Oct 14, 2013.

  1. Boatman

    Boatman Membership has it's privileges ;-)

    Joined:
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    11,825
    Location:
    Petersburg, NY and Mill Spring, NC
    Tight intake valves:deal
    #21
  2. Gustavo.Ramos

    Gustavo.Ramos Long timer

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    will check it too.

    start to think that work more on friends bikes than my own......
    #22
  3. Gustavo.Ramos

    Gustavo.Ramos Long timer

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    digging a bit of a thread.

    No tight valves, checked them and only one in front cylinder was a bit tight but still within range.

    While riding occasionally it feels a bit of a fart into the airbox, especially at low revs. Spark plugs are ok with good color. Thinking about injector operation... related to random incorrect spray time, a fraction of a second off the valve opening time, perhaps...
    #23
  4. srad600

    srad600 Been here awhile

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    Interesting, I have a 2011 990 with the exact same symptoms. Bike runs perfectly under power, on decel, overrun, etc. But every once in a while, if stopped at a light with the clutch pulled in, when rolling on the gas the bike will pop/fart and then stall. It'll start right back up and run like mad, but the occasional stalling thing has me stumped.

    I've :
    Sync'd the Throttle bodies
    Set the TPS
    Checked the Map (Powertripp)

    I will be:
    Checking the valves this next service (but they were fine at the last check)
    Replacing the plugs

    I'm running a foam filter now, but the issue occurred prior to the new filter. I've just started rolling on the gas harder/earlier from a stop. It's a band-aid, but I haven't a clue what else to check.
    #24
  5. Bowber

    Bowber Been here awhile

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    Never seen that before and I raced speedway and grasstrack bikes for 30 years running pure methanol. On carbs though.
    The carbs would get gunked up if left (but took a while, like a month or more) and some parts would corrode badly but nothing in the inlet.

    Steve
    #25
  6. cejnys

    cejnys Been here awhile

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    hey Gustavo,

    Just wondering whether you found out what was the problem. I have 2012 990 Avd and it runs well under power but when I start it after like 5-10 seconds engine stops when rear cylinder back fires into the intake. Also when I am starting to rev the engine up it does not feel right until it reaches about 4000 revs, then is feels good.

    I looked into the airbox and this is what I found. Rear intake is pretty smoked and front is little bit oiled. Last valve check was all good.

    I am riding around south america right now; last 3 weeks with adding more kilometers it got worse. At this moment it is pretty challenging to go slowly with the bike. I have to keep revs up and ride it through clutch.

    Any advise will help! Cheers, Rad

    <a href="http://s1381.photobucket.com/user/aroundsouthamericainfo/media/KTM%20faults/NIK_2141_zpsjysi1tjs.jpg.html" target="_blank"><img src="http://i1381.photobucket.com/albums/ah220/aroundsouthamericainfo/KTM%20faults/NIK_2141_zpsjysi1tjs.jpg" border="0" alt=" photo NIK_2141_zpsjysi1tjs.jpg"/></a>
    #26
  7. Gustavo.Ramos

    Gustavo.Ramos Long timer

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    Hello CEJNYS,

    swapped rear injector from another TB set that i had in my spare parts, cleaned the intake area and for about a month nothing was found. Original injectors were sent for cleaning and the issue was solved.

    But from your description yours seem to be alot worse and before going the injector way i'd check that rear spark plug. some plugs when get randomly faulty their effects are felt at lower revs because at higher revs the firing cadence is much faster and it masks the symptoms.

    And if you have such condition, the missfire will cause the very same buildup goo that you see.
    #27
  8. Gustavo.Ramos

    Gustavo.Ramos Long timer

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    This picture resembles now a lot of the early cases of dust ingress in the 1190 Adv airbox
    #28
  9. MortimerSickle

    MortimerSickle Semi-Adventurer

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    Location:
    Rainville, Orygun, where moss is a road hazard.
    Same engine after 36000 miles on ethanol gas.

    [​IMG]
    #29
  10. Gustavo.Ramos

    Gustavo.Ramos Long timer

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    does it feel and runs healthy? if so, thats what matters
    #30
  11. MortimerSickle

    MortimerSickle Semi-Adventurer

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    It does, and as you can see the gunk is gone, so all is well.

    Why it accumulated, and why it went away is a mystery for someone else to solve.

    My only point was that I don't believe ethanol gas was the source of the gunk.
    #31