990 Jerky throttle

Discussion in 'Dakar champion (950/990)' started by Nine90, Oct 12, 2008.

  1. easyman05

    easyman05 Been here awhile

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    Nice try, you have a gift of explanation, thank you!:clap Do I get it right - that if I am more gentle and smooth on gas than I would not feel any jerkiness?
    In comparison with Africa Twin - both bikes seem to have similar weights - which one is smoother? And more capable and comfy? TIA
    #41
  2. azkiwi

    azkiwi message in a bottle

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    Really, its the immediate off-idle transition where it is less than clean - you don't notice it in higher gears because a small throttle opening has a less profound effect on a pull at the bars, and you especially notice it on low gear and trying to go slow.

    As soon as you get beyond the off-idle transition and into a larger throttle opening, it fuels cleanly. So while riding aggressively its great, but for obvious reasons grabbing a big handful isn't always the best thing to do in slow technical terrain.
    #42
  3. azkiwi

    azkiwi message in a bottle

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    I would love to hear why it makes any difference on the main stand.
    #43
  4. Moraflex

    Moraflex Banned

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    Exactly what I did. Don't forget the two bar warm up so the system can set its self.
    #44
  5. Moraflex

    Moraflex Banned

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    I just spent the day installing a Kouba link on my XR650L, lowering the forks, oil change, new chain, put on the factory 15 tooth sproket and took her for a spin. Vary nice and I can now touch ground. So, I pull out the 990 KTM, lube the chain, slap on the GPS and take her for a ride. Holy shit what a difference between the bikes. The KTM is so much more balanced and stable. I can come to a stop sign and not even put my feet down. I love this bike.
    #45
  6. Nailhead

    Nailhead Inclusion Rider

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    I still can't help thinking that is a large part of the problem (in my case, anyway). Anyone know whether a heavier throttle return spring is obtainable?

    Chris
    #46
  7. K80JIM

    K80JIM Super Tanker

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    I would think the heavy return spring would make things even worse. If you got into a little rough spot or hit a few bumps it would be even harder to hold the throttle on one place.

    I did put on the G2 and have only used the 300 but it took care of about 75% of the problem. Might try the 400 just to see if it helps even more.

    Jim
    #47
  8. Nailhead

    Nailhead Inclusion Rider

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    No, it makes it much less likely that bumps will cause involuntary throttle inputs. At least that what my experience suggests...

    Chris
    #48
  9. easyman05

    easyman05 Been here awhile

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    what looks strange to me is the fact that we are talking about an enduro/DS/ bike. Isn't it supposed to be smooth in low gear and revs - for stone/cobbled/ terrain or water fording or sand/gravel traps?
    just I am puzzled and intrigued - have to test ride one.
    #49
  10. easyman05

    easyman05 Been here awhile

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    +1
    We had similar issue with K1200GT bikes/2nd generation/ several years ago - ON/OFF throttle below 3000rpm. BMW changed the design of airbox, idle control valve and updated software respectively. OK now.
    The heavy return spring also will make long hauls painful for the wrist - from experience.
    #50
  11. max.headroom

    max.headroom That "Retro" Digital, Ummmm ..... Dude.

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    Well .... that seems to be working for me ..... but I'm also going to, as in I decided, that I am going to get the G2 / 400 ......

    I think the mixture of me getting more use to the bike, and the G2, will do the trick for where I want it to be at ......

    As for the Twin v.s. the 990 - well, in some ways there's no comparison.
    1992 v.s. 2007 ......

    The twin is a great bike, and I love her. Seriously .... Though she's "old school". I've had the twin on dirt and she handles it just fine, really ....
    I have not (yet) had the KTM on dirt - but I can already tell .....

    The KTM is far superior in the sense of being nimble, in handling - that KTM can F'ing carve on the pavement - and I'm positive it's going to be better on the dirt than the twin. But .... I love my twin. :D To me a comparison of the two are somewhat apples and oranges ....
    One's a 750 ... the other a 999 .... one's carbed, the other EFI ..... the rear on the twin is a 130 / 80 - 17, whereas on the KTM it's 150/17 - 18 as you know ....

    If anything - I will say that the Twin was a little more comfortable than the KTM for a long distance trip - but with the sheepskin I had for the haul back from Santa Fe - I was quite comfortable ......

    All in all ...... I'm glad I have both bikes ..... :lol3

    G.
    #51
  12. Fettler

    Fettler n00b

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    I just changed from the K300 cam on the G2 tube to a K400. The 300 was good and I thought that would do it, but just for science I put on the 400. It is really soft. After doing 100+ miles on the 300, I changed to the 400 for the ride home. It was almost hard to make the bike jerky. At one point I thought that it might be too soft, but I got used to it and full service was resumed. After thinking about it I guess I'd rather adapt to a soft throttle feel, than a sharp one. At the end of the ride I could see that if you had a long day on the plank, a 400 would be a lot less tiring.

    On the return springs - heavy ones don't suit big miles and I doubt that they would help much with the "feedback" problem on bad terrain. What does make a difference is damping the throttle action. You can do this easy experiment.

    Loosen the two cable housing bolts (where the cables are attatched to the throttle grip) and push the end of the grip outwards into the brush guard until it drags - not too much!. This acts as a crude damper. Try the bike on a broken up trail. It works, but something will wear out if you do it for too long and I don't like the feel on smooth pavement.

    What would be good would be an adjustable disk damper fixed to say the cable housing on one side and attached to the tube on the other with heavier springs. This way you could snap the throttle open against the heavy springs and the damper would follow round under the heavy spring tension, but you wouldnt have to hold that tension after the damper had rotated. If you do slower throttle movements you just have the regular spring tension.

    Anyone with facilities interested? I can produce a diagram if so. This seems to be the biggest problem with FI Advs.
    #52
  13. Dusty

    Dusty Long timer

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    I you want to add some friction to the throttle you could install one of these...
    [​IMG]

    I wont work well with the G2 cause it is made of metal and the Kaoko pushes the throttle tube inward against the housing which is metal also... metal against metal make for a not so smooth throttle action... so you could make your own G2-400 cam out of the stock throttle tube...
    [​IMG]

    [​IMG]
    #53
  14. Dusty

    Dusty Long timer

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    #54
  15. comsubin

    comsubin slower than i think

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    Totally agree with difficulty on maintaining low speed, especially hitting roundabouts which, here in australia, are pretty covered in diesel spills.

    I went for my first decent ride today on my black 2007 990 adv, and found that "jerkiness" the only issue.

    Well, it might be associated with the throttle problem but I found my right hand suffering numbness from vibration. Since it is not both hands, has anyone experienced the same thing?

    If yes, has the use of the G2 cam solved it?

    cheers
    Les
    #55
  16. azkiwi

    azkiwi message in a bottle

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    You might just be working that hand too hard trying to be smooth. I got some of that before a G2 and 16T. Not perfect, but much better.

    Still, a mid corner correction is something you learn not to do.:knary
    #56
  17. comsubin

    comsubin slower than i think

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    I will invest in that G2 on the first service then, thanx!!!!
    #57
  18. ktmmac

    ktmmac .

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    My 990 was difficult at low speeds when I first got it. I've put on the Akra's with map a 16 t front sprocket and now it's fine. I think it is a mileage thing though. It did appear to get better as I got a few miles on the clock.
    So in order, the Akras help, sprockets is easier around town makes acceleration more fun! But I really believe you need some miles on it.
    These motors seem very tight when new, certainly mine never bothers me now. Maybe I've just got used to it.
    At 23,000 miles it's also stopped using oil now!
    Great bike though, just love it.
    #58
  19. Justwantoride

    Justwantoride Been here awhile

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    Old thread I know... But would someone find me a link to the model that I need for my 990R? Everything I am finding says they're for dirt bikes and don't list the adventure as being compatible.

    Thanks
    #59
  20. knobbyjoe

    knobbyjoe Adventure and dirt rider

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    http://www.g2ergo.com/store/g2-throttle-cam-system/

    Here is a site that you can choose Make: and Model: and shows it is for the 990. I use the G4.
    #60