Carbon on Intake Valves

Discussion in 'Parallel Universe' started by dpike, Jan 13, 2018.

  1. dpike

    dpike BeeKeeper

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    started my 12k service today and noticed quite a bit of carbon on the intake valves, more than i would expect at this mileage. anyone notice the same ? are people treating with techron or seafoaming their intakes at all ?

    [​IMG]
    #1
  2. Rider 101

    Rider 101 Time poor

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    Found the same on the inlet on my WR250R at 4000km. I had the motor out so was an easy job to carefully scrape off then give a diamond lap. The only explanation I had was a bit of blow back.
    #2
  3. Indy Unlimited

    Indy Unlimited Long timer

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    Yeah the intake valves are not sealing properly. I usually see clean intake ports and valves upstream of the intake seats.
    Definitely time for a valve job. Most likely with that low mileage the seats were never cut right from the factory.
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  4. dpike

    dpike BeeKeeper

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    :fpalm
    thanks guys.

    being there's a little oil in my airbox i was under the assumption it was from that.

    i'm pretty sure valve job isn't happening right now, opinion on letting it go for another 10 or 12k ?
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  5. Bayner

    Bayner Long timer

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    If you can get a small amount of water in there while the engine is running and good and hot it can remove some of those deposits. On a car I'd use a vacuum line, you'll have to be a bit more creative I suspect. Seafoam would also help, but geez, it makes some nasty smoke.
    #5
  6. dpike

    dpike BeeKeeper

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    i foamed my wife's mini thru the intake and yeah, it was a mess. fuel treatments don't have much of an effect on direct inject vehicles, but since fuel passes over the valves here i'll try techron or seafoam treatments once every thousand miles or so for a bit and recheck in another 10k.

    if i was a more knowledgeable wrencher or didn't work 12 hours a day i might find dropping the motor to do the valves something i could tackle, but right now it's just not an option.
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  7. Indy Unlimited

    Indy Unlimited Long timer

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    You should be okay running it another 10 to 12 K , but at some point it will cause a drop in performance and other difficulties. You will notice when it is time to get it serviced.
    #7
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