More KTM problems

Discussion in 'Mechanical & Technical' started by ZXWUT?, Oct 16, 2012.


  1. ZXWUT?

    ZXWUT?
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    I've got a 2005 KTM 625 SMC. The carb has been dipped and cleaned and jetted per jd tuning. It was supposed to have worked well with that combination before. For the past few months, I've had an issue with the bike cutting out very momentarily then back to normal. It would also backfire and spit flames out the exhaust pretty bad on decel. It got so that it was really bad and I thought it was jetting. I tried tons of different jet combos and nothing helped so I put it back to JD's recommendation. I pulled the spark plug and it was black and smelled like gas. I put a new plug in the boot, held it against the head, and the spark was weak. I pulled the coil, cleaned the ground, put it back together, and it ran great. That lasted for about 100 miles and it started again so I replaced the coil and spark boot. That cleared it up for a few more miles and then the issue came back. It doesn't do it as badly or as often, but it's terribly annoying and I'm sure it's not good for the engine either. Does anyone have any ideas on what I could check or what would be causing this? I'm really considering offloading it and cutting my losses if I can't figure it out; its been a nightmare. Thanks.

    Edit for extra info:
    Forgot to mention in the original post that the hiccup only happens at steady speed/steady throttle, and on decel with some gas applied. Full throttle seems to be fine. It doesn't do it steady either, it's very intermittent and sometimes happens very often, and other times it might be a few minutes before it does it.
     
    #1 ZXWUT?, Oct 16, 2012
    Last edited: Oct 16, 2012
  2. Grantizzle

    Grantizzle
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    i don't remember if you have done the SAS delete or not. helped mine out.
     
  3. ZXWUT?

    ZXWUT?
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    It's already got all the normal mods.
     
  4. RedKat600

    RedKat600
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    Vintage Screwball
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    Black plug = rich
    Flames out exhaust = lean
    Flames out exhaust = rev limiter on my Suzuki

    Do those have an auto-compression release on them? May want to look into that....

    Something isn't right there....checked your valves lately?
     
  5. ZXWUT?

    ZXWUT?
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    Valves were fine a couple hundred miles ago.
     
  6. RedKat600

    RedKat600
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    Those have a TPS on the carbs? Not familiar with what models do or don't.
     
  7. ZXWUT?

    ZXWUT?
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    They do indeed.
     
  8. sunofnun

    sunofnun
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    Retired

    Mine had a problem with the auto comp sticking.. same symptoms..
    Check that.

    Also there are a MOUNTAIN of links here:
    http://www.advrider.com/forums/showthread.php?t=86958
     
  9. ZXWUT?

    ZXWUT?
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    I'll check that out tonight. How/what do I do to check if it is sticking or not?
     
  10. ZXWUT?

    ZXWUT?
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    Forgot to mention in the original post that the hiccup only happens at steady speed/steady throttle, and on decel with some gas applied. Full throttle seems to be fine. It doesn't do it steady either, it's very intermittent and sometimes happens very often, and other times it might be a few minutes before it does it.
     
  11. sunofnun

    sunofnun
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    pull it apart.. lube it put it back together?
     
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  12. ZXWUT?

    ZXWUT?
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    I was afraid you'd say that.
    Posted via PNW Riders Mobile
     
  13. metricinch

    metricinch
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    sorry, i have nothing constructive to add, but ^^that caught my eye. :devil:
     
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  14. BusaDave

    BusaDave
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    Mine is just starting to have the same issue. Been too lazy to pull it apart and check it out.
     
  15. ZXWUT?

    ZXWUT?
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    crackup:
     
  16. ZXWUT?

    ZXWUT?
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    Well if you figure it out before I do, let me know!
     
  17. BusaDave

    BusaDave
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    Will do.
     
  18. ZXWUT?

    ZXWUT?
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    Looking at the manual, I might be able to get to it without pulling the valve cover. That'd be nice.
     
  19. coastiepete

    coastiepete
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    Rob, have you thought about getting some help from Nels? throwing it on the dyno and getting some data might get you some help.

    Did you pull the TPS off when you had the carb dipped? if you put it back on wrong, that could really mess it up.
     
  20. ZXWUT?

    ZXWUT?
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    I did not remove the tps. I hung the carb from wire so I wouldn't have to.
    Posted via PNW Riders Mobile
     
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