Iridium spark plugs running lean?

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Iridium spark plugs running lean?

icerigger
I just switched to iridium plugs this spring and I like them a lot. But I just pulled them to check on their condition and it looks like I'm running lean, there's white ash on the plugs.

Is this normal? I don't recall anyone having to rejet to use iridium plugs.

No other changes to the bike over last year and the regular plugs were a nice toasty brown when I took them out. Carbs and jets are all stock.


Livin' my life like a song.

1985 Honda Rebel 250 - "Birdie"
1979 CB750K - "Behemoth"
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Re: Iridium spark plugs running lean?

Lucky 1
No other changes to what?  What was the bike set up?

Did it have stock exhausts? Did it have stock intake?
We don't keep track of each bike.

Working in the dark.

Did it have the stock heat range of iridium plug equivalent to NGK's?
On a Roadstar Adventure.
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Re: Iridium spark plugs running lean?

TOOLS1
Administrator
In reply to this post by icerigger
Does the ping, or knock?
TOOLS
Life is not about the number of breaths, you take, but the moments that take your breath away.
I don't have an anger problem. I have an idiot problem. Hank Hill
Never confuse education for intelligence.
Happiness is a belt fed weapon.
I just can't imagine what could go wrong.
No fire? No explosions? So whats the point of your story?
Those who are too smart to engage in politics are punished by being governed by those who are dumber. ~Plato
It couldn't be done, but the darn fool didn't know it, and did it anyway.
We all got problems. Ksharp
I like vintage bikes because they take me away from the clutter of technology that I work with everyday and back to a simpler time of mechanical elegance and simplicity.. "ninadm"
Darkwing Duck: The worst part of public transportation is the Public.
"That is awesome shit there" Re-Run
"Fear nothing, attack everything" Eric Berry
" Oh, you read that on the internet? Clearly it IS a massive problem. Of course it CAN’t be normal operation."

1976 CB 750-A X 2
1977 CB 750-A X 4
1977 CB 750-K
1976 CB 750 F
1981 CB 750
1966 Kawasaki SG 250
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
1982 Honda XL 80
South of Eden (Kansas City MO)
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Re: Iridium spark plugs running lean?

MarkPBG
In reply to this post by icerigger
If the ash is light grey (almost white) then that is normal....even as shown on NGK's website...
http://www.ngksparkplugs.com/tech_support/spark_plugs/faqs/faqread.asp

If you were running hot, you would, in addition to the whitish ash, see the porcelain beginning to blister, and you would also notice slight wear on the electrode. The iridium plugs have sharp edges on the electrodes....if they've rounded off more than just an almost imperceptible bit, then you may be running hot. The center electrode will become rounded with overheating.
Mark Davis
Palm Beach Gardens, FL
amateur photographer, hot rodder, motorcyclist, adventurer
"Four wheels move the body. Two wheels move the soul."
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Re: Iridium spark plugs running lean?

icerigger
In reply to this post by Lucky 1
Lucky, sorry for the confusion. The bike in question is  the '79 CB750K in my sig. Everything is stock, no chops, no mods, no pods. Exhaust is stock 4x4.

Adjusted the valves last fall before putting it away for the winter. In the spring did an oil change, swapped out the stock plugs (nice tan colour) for the iridiums, synced the carbs and rode away.

Did an oil change last week and checked the plugs, white ash.

Tools, I am getting a bit of ping under heavy acceleration after it gets good and warm, 10-15 min depending on the weather.

Mark, I'll pull the plugs and have a closer look.

Thanks guys.
Livin' my life like a song.

1985 Honda Rebel 250 - "Birdie"
1979 CB750K - "Behemoth"
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Re: Iridium spark plugs running lean?

icerigger
In reply to this post by Lucky 1
Sorry, I forgot to mentions the plugs are the standard heat range. Old plugs are D8EA, iridiums
 are DR8EIX.
Livin' my life like a song.

1985 Honda Rebel 250 - "Birdie"
1979 CB750K - "Behemoth"
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Re: Iridium spark plugs running lean?

TOOLS1
Administrator
In reply to this post by icerigger
Since you are getting some "ping" you should be a little richer.
TOOLS
Life is not about the number of breaths, you take, but the moments that take your breath away.
I don't have an anger problem. I have an idiot problem. Hank Hill
Never confuse education for intelligence.
Happiness is a belt fed weapon.
I just can't imagine what could go wrong.
No fire? No explosions? So whats the point of your story?
Those who are too smart to engage in politics are punished by being governed by those who are dumber. ~Plato
It couldn't be done, but the darn fool didn't know it, and did it anyway.
We all got problems. Ksharp
I like vintage bikes because they take me away from the clutter of technology that I work with everyday and back to a simpler time of mechanical elegance and simplicity.. "ninadm"
Darkwing Duck: The worst part of public transportation is the Public.
"That is awesome shit there" Re-Run
"Fear nothing, attack everything" Eric Berry
" Oh, you read that on the internet? Clearly it IS a massive problem. Of course it CAN’t be normal operation."

1976 CB 750-A X 2
1977 CB 750-A X 4
1977 CB 750-K
1976 CB 750 F
1981 CB 750
1966 Kawasaki SG 250
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
1982 Honda XL 80
South of Eden (Kansas City MO)