NGK Plug Check

Last week the bike kicked me back 3 times while trying to start. Another guy with more lead in his tush kicked it to life and I got home okay, but after sitting for a week it wd not start at all. Clamping the plugs to the head, ignition on, room dark, no apparent spark. I'd been wondering how long an old analog Boyer cd be expected to last, pulled off the (practically new) ignition switch, and got continuity on the hot (NU) wire all the way past the rectifier and capacitor to the switch. I assume the smoke goes to the white wire from there to the kill switch? Good continuity at every ground point I touched from the red battery wire. Charged the 4 year-old battery and then just bought a new one, harboring doubts...
Anyway, I was just about to pull the switchgear off to see what the kill looked like, began to look for Boyer diagnostics, etc., and then pulled up short to check the plugs themselves. See anything wrong? Only a few hundred miles on them.

Looked pretty good to me, but having 2 fresh sets, I pulled off the NGK's and clamped a pair of Champions to the head. Immediate light up in the dark, put all back together, fired right up.
Turns out both plugs (non-resistor) failed continuity on the center electrode. They're both dead.

Moral: Use an ohmmeter or continuity tester to check the easy (and cheap) stuff first. Resistor plugs shd (I think) show not much more than 5 or 6K ohms, non-resistors close to zero, from the top terminal to the center electrode at the bottom.
Neither shd pass current from center electrode/top terminal to the body or threads.

Question 1: Can a failing Boyer kill spark plugs?

Question 2: Does the new micro-digital Boyer have a "slow start" accomodation?

My Norton ever since new has always run best on Chapion plugs N7YC everytime I have used other plugs as well as NGK to the same heat range as the Champions they play up with in a week I have always got long life out of my Champion plugs and now running a JH maggie they last even longer as the JH has a hotter spark and the plugs are always very clean when I inspect them, most of the time I just put them back in without touching them.

Ashley

I have a Pazon Smartfire on my 500 single and coincidentally it used to kill NGK plugs (B8ES) quite regularly - to the extend I always had 2 spare plugs with me.
Nothing looked bad about the failed plugs - they just stopped sparking.
I contacted NGK technical and even mailed one to them for evaluation - never heard from them again.
What fixed it for me was changing to iridium (BR8EIX) - not one failure since.
Go figure!!
Cheers
Rob
I did check them all looking for signs of being fakes but all seemed okay

robs ss said:

I have a Pazon Smartfire on my 500 single and coincidentally it used to kill NGK plugs (B8ES) quite regularly - to the extend I always had 2 spare plugs with me.
Nothing looked bad about the failed plugs - they just stopped sparking.
I contacted NGK technical and even mailed one to them for evaluation - never heard from them again.
What fixed it for me was changing to iridium (BR8EIX) - not one failure since.
Go figure!!
Cheers
Rob
I did check them all looking for signs of being fakes but all seemed okay

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Must confess have always been a fan of Champion . They will foul and clear ... NGKs just stop

Thanks for all the responses.
These dead plugs pass the fake checks; good printing, silver colored plating, 4 digit stamped hex flat, tight gasket.
So I reckon I'm done with NGK, based on this experience and others' observations.

Well, one thing I have noticed is NGK plugs run a little colder than the cross reference would indicate. If your bike is a little rich then NGKs may foul quicker.

But I would say I have never encountered these kinds of problems with NGKs or Champions.
I probably have NGKs in my bike now. It's been a long time since I have looked at them.
I always used Champions in my racebikes. Jim

PS,I did get some knockoff NGKs for my chainsaw a couple years ago. They didn't work too good.

In german, we say: NGK means "nur ganz kurz" (only very short)
Always use Champions on all older bikes and never had problems

When I used to do some car servicing I used to buy plugs in bulk, I often found 1 or2 dud plugs in a box of 10, they would spark for some time if used,But I always tested them before installation. I use some really old stock Lodge or KLg and they rarely give trouble, Good enough for a merlin engine ,still good.

My NGK B8HS plugs do go open circuit after some use. The copper core seems to lose contact with the top terminal. They still work though.

norton bob said:

When I used to do some car servicing I used to buy plugs in bulk, I often found 1 or2 dud plugs in a box of 10, they would spark for some time if used,But I always tested them before installation. I use some really old stock Lodge or KLg and they rarely give trouble, Good enough for a merlin engine ,still good.

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In the 70's Champion plugs had a pretty bad reputation. I think I remember hearing that approx. 20% would be dud out of the box.

In my experience the NGK will just suddenly stop working. Especially the resistor ones.

Cheers,

cliffa

DocShoe said:

In german, we say: NGK means "nur ganz kurz" (only very short)
Always use Champions on all older bikes and never had problems

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There was a Tv soap that featured a horse called champion .. there was a refrain 'champion the wonder horse.... and thus many years later I find myself humming Champion the wonder plug.. I fully agree with you.

cliffa said:

In the 70's Champion plugs had a pretty bad reputation. I think I remember hearing that approx. 20% would be dud out of the box.

In my experience the NGK will just suddenly stop working. Especially the resistor ones.

Cheers,

cliffa

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In the 70s they did have a bad batch that took them some time to f ind they had a problem thats when I went with other brand plugs before going back to Champions has so much troubles with NGK and other brands with the same heat range but I think they were a little out from the Champions.
Have had no problems after that with the Champions other plugs I get a week out of them before they start to misfire never had that problem with the Champions always got long life out of them.

Ashley

I have been using NGK BP7ES plugs for decades with no failures, always perfect.
Yet I see other posters above using different numbered NGK plugs reporting failures, etc.
Perhaps they are not using the proper specified plugs, from my memory it has always been BP7ES

of course nowadays with my Trispark I am using resisters, NGK BPR7ES

The plugs which failed are BP7ES, as recommended.
It's a disappointment for me; the NGK's were easy to find and not expensive, and I had used them (not these particular ones) for several years.
FWIW, the (larger, 4-plug) box has tiny digits stamped into the flap of the lid: 162013
The individual boxes are printed on the inside flap in red: *E11*

NGK BP7ES is what I have used and they play up, as Jim said they are just a bit colder and not a perfect match to the Champions even if they are cross matched, but most bikes are different and some will work fine with them, just my Norton doen't and will aways get a misfire just after a week of running them, don't have that problem with the Champions.

Ashley

I use NGK iridium number 8 for normal use and number 9 for track days and dyno sessions.

Does that sound about right to folk ?

(For ref: 10.5:1 CR, 850, JS1cam)

I found long ago that ‘normal’ NGK road plugs would barely last a race and definitely not an entire meeting in my Triumph and NRE motors. I waisted a serious amount of time and energy chasing misfires etc until I went over to proper NGK race plugs under the advice of Degens and Nourish.

Trouble is, they were seriously expensive and made for poor starting. I have found iridiums to have the benefits of the race plugs without the down sides.

So iridiums are all I stock in the ‘shop’ these days.

Iridium NGK plugs only lasted few weeks in my commando
It had been gradually harder to start then yesterday after I'd eventually managed to get the engine running for maybe a minute or so it just cut out
I pulled the plugs and they were barely sparking
I tried an old pair of NGK bp7es plugs and got a proper spark so I fitted them and the bike started immediately and ran fine ,I run my Norton fairly lean never rich I wonder if the richness of tickling the amals to start the bike has killed them?
Someone did mention this in earlier post so maybe it's a known problem ? Cheers

baz said:

Iridium NGK plugs only lasted few weeks in my commando
It had been gradually harder to start then yesterday after I'd eventually managed to get the engine running for maybe a minute or so it just cut out
I pulled the plugs and they were barely sparking
I tried an old pair of NGK bp7es plugs and got a proper spark so I fitted them and the bike started immediately and ran fine ,I run my Norton fairly lean never rich I wonder if the richness of tickling the amals to start the bike has killed them?
Someone did mention this in earlier post so maybe it's a known problem ? Cheers

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It's just dawned on me I'm running resister plug caps , could this have killed them?

The nice thing about Champions, they have such a crappy reputation that no one would bother faking them.
Having said that, Champions have always worked fine for me.
I've got a drawer full of new eBay fake NGKs.

Glen