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Thread: plugs/tuning

  1. #1
    Joined
    Jan 2002
    From
    St. Amant, La.
    Posts
    12

    Post

    I read about proper tuning by looking at the color and deposits on the surface to the plugs. My question is when burning synthetic oil Pennzoil, are you going to have anything on the plugs? I have burned synthetic oil in my outboard engine and never see anything at all on the plugs and its been running for years like this. I made a trip (my first ) this week on my kaw1100zxi and checked the plugs after and show nothing -- looked like I just put them in. They did have a slight oil look to them only but no build up.
    PT Cruiser

  2. #2
    Joined
    Feb 2001
    From
    Clearwater, FL
    Posts
    7,373

    Post

    You're probably not looking at the right parts of the plug. I have some here in the shop I can show you what to look for on.

    The part you want to look at is the rim of the threads. This is where you want a nice dark borwn color to appear, to indicate your proper mixture. The actual porcelin indicates the heat range of the plug. You also want this nice an dark brown. Too light means it's too hot for the engine, black and sooty means it's too cold. You will also have a hard time getting any mixture readings on a plug that is the wrong temp range. It must also be gapped correctly!

    This plug shows a slightly hot heat range, and slightly rich mixture. It's still fairly dry, not much oil and fuel gooped up but the rim color is all black.



    This plug shows again, a slightly hot heat range, but the mixture is slightly lean, as shown by the mostly clean, colorless rim. Getting color evenly all the way around the rim is almost impossible, due to the electrode tip in the way of the charge flow. Go by the majority reading.



    This plug is almost just right! The temp reading is nice and dark brown, although it could be a *touch* lighter, the rim has even color and it's also nice and dark brown with no excess gooping or black deposits.




    [ March 27, 2002, 01:46 PM: Message edited by: Bryan Glynn ]

  3. #3
    Joined
    Jan 2002
    From
    St. Amant, La.
    Posts
    12

    Post

    thanks Bryan the pictures were great and helpful. I look at this site everyday. It's the best. Thanks again.
    PT Cruiser

  4. #4
    Joined
    Mar 2002
    Posts
    47

    Post

    One additonal point to Bryans exellent photograpy exhibit.

    Never attempt a plug reading on NEW plugs, you could be very lean and not notice until too late.

    Also, getting a plug reading is sorta specific, by "local" standards anyway.

    "WE" do it this way.

    Get the engine up to full operating temperature.

    If you are certain it is not too lean, proceed.

    Open the throttle full and hold it there for at least 1/4 mile.

    While wide open and full rpm, hit the kill button and release the throttle at the same time.

    Do this in a safe area to not endanger yourself or others.

    Have a drink of water while the plugs cool a bit.

    Pull them and observe, remember to remove your #14 shades when making decisions [img]smile.gif[/img]

    Turn them upside down into the hole they came from as you remove them to determine which cyl needs leaning/richening

    Always take spare plugs to replace water fouled or dropped ones.

    [ March 28, 2002, 08:04 PM: Message edited by: DrVette ]

  5. #5
    Joined
    Feb 2001
    From
    Clearwater, FL
    Posts
    7,373

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    That's true, that's how you ultimately check the high-speed circuit after you're done checking the low and preferably checking the high at mid throttle.

    What I do is ride for at least 1 minute at 10% throttle, then pull them. This lets me dial in the low. When that's down pat, fine tuning by throttle responce after idling and checking for any bog or hesitation, I go to mid-throttle.

    I do the same thing at 50% throttle, adjusting the high-speed circuit, then repeat at 75% and 100% throttle. For these three tests you must pull the lanyard while holding it at speed, as to not contaminate the results by dropping back down to a lower thorottle range, and thus lower curcuit. And yes, if you're wondering, that means you either must be able to float out there and pull your plugs, or be towed in to the beach or what have you.

  6. #6
    Joined
    Aug 2003
    From
    Canada
    Posts
    37

    Post

    First off...love this site and would be lost without it ;)

    I've heard many opinions on carb tuning and just don't know which way to go. SBT is saying tuning by plug color and Group K says not to use plug color, but use pop-off pressure and alot of "how it sounds/feels".

    Ummm...HELP!!

    I have a 92 650SX that was stock last summer and barely used. Since then I've rebuilt the carb (CDK2), added a high comp RoGo head (up to 190psi now), R&D toploader grate, primer, and pump blockoff. Soon to add a longer exhaust cone.

    The ski seems to run well but mabye a tad rough at idle. What should I do to tune? With my setup do I have to tune more than the carb (i.e. ignition or other)?

    Thanks in advance for any help.

    Cheers

  7. #7
    Joined
    Mar 2003
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    SBT
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    The very best way to tune is using a combination of plug condition, EGT's, Engine performance and examining the piston wash. The only things the average consumer can use are the plugs and performance. On a relatively (non-race) ski, using our methods works for the vast majority of cases. That doesn't mean it's the only way, however.

    Describe exactly what happens with your ski in a new post.
    SBT Tech Support is here to help with your problems.
    We try to answer each question quickly and accurately.
    Please do not use Private Messaging for Tech Support, use the forums.

  8. #8
    Joined
    May 2004
    From
    clearwater
    Posts
    76

    Post

    ok, I follow you on the rim color as far as lean or rich condition, but you lost me on the heat range(br8hs is what is supposed to go in my 99 yamaha xl 700 and if 8 is the proper heat range for my engine but the porcelein is white or clean and the rim is dark brown then it has the proper amount of fuel but too hot a plug? also I found the carb adjusting instructions were great until I read this and realized that I was not checking the high screw setting properly!!! Please add this link to those instructions as a newby would take this for granted as I did. maybe just me but the one line about stopping right at full throttle makes all the difference in the world. thanks for ALL the help and info, keep up the good work!!!!! please!

  9. #9
    Joined
    Mar 2003
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    SBT
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    If your insulator is still white, you just don't have enough time on the plug yet - that's not something that colors right away.
    SBT Tech Support is here to help with your problems.
    We try to answer each question quickly and accurately.
    Please do not use Private Messaging for Tech Support, use the forums.

  10. #10
    Joined
    Jul 2004
    From
    Nashville, TN
    Posts
    20

    Default Re: plugs/tuning

    Can fouled plugs be cleaned and reused? If so, how??

    about how much time is needed on a plug to get good colour?

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