NGK Spark Plugs. Recent quality

Convert

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I run NGK BP6ES plugs in my 1976 Moto Guzzi Convert motorcycle. Engine looks and operates the same as my Kawasaki FH641v, both engines are 90 degree V twins, the only difference is the layout.
The Guzzi engine/ bike ( 67000 miles) the crank is horizontal while the Kawasaki (575 Hours) is vertical shaft. Actually they are cousins as far as design goes

What I'm getting at is both of these engines are aircooled, run at high load, and both use NGK plugs without issues,
with other plugs (mfg) not so much

TOMB
 

TylerFrankel1

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I'm not a shop owner but I do a lot of small engine work from my house when I can... I've fixed 6 push mowers for neighbors so far this season, and repaired several trash picks and a tractor (thanks to this forum might I add! Appreciate it!) I got 4 leaf blowers, worked on some string trimmers, have a go kart, a chain saw, a couple generators, a couple of pressure washers, yard vacuums, and yet...
I've never experienced a bad spark plug. I really am dumbfounded. I've worked on probably 40 or so engines at this point, and never encountered a non-firing plug. the NGK ones I have all work fine, so do champions, etc.
I'm Sure this will get me a lot of hate but admittedly I don't change plugs much anymore, because like I said they just aren't ever goin bad for me. If I have a rough/bad running engine or no spark I'll put a different plug in as a test measure to see if it improves, but otherwise, I just leave them. So far, not one is bad!
 

Hammermechanicman

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In my shop all i have are champion and some NGK. More important than What brand us in the engine but is the plug of the correct heat range. Many cross reference charts lump together 3 or 4 plugs of different heat ranges to cross one plug. So if you cross brands to a colder plug and it fouls in a few hours folks like to say that brand is trash. My 22 year old stihl FS80 has the original plug in it and it runs fine. If a spark plug is not operating in the self cleaning range of about 850 to 1000 degrees F it will carbon foul. My commercial customers run stuff hard enough i never see fould plugs but residential customers that baby the equipment or run it for short periods foul plugs all the time. The magneto ignitions on small engines don't generate the energy to eroded plug electrodes much. If the engine is operated so the plugs operate in the self cleaning range they should last a very long time.
 

cpurvis

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NGK has achieved enough brand recognition that counterfeits may be appearing.
 

jakewells

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I use NGK or autolite and both are good in my book i never did like a champion.
 

bertsmobile1

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I'm not a shop owner but I do a lot of small engine work from my house when I can... I've fixed 6 push mowers for neighbors so far this season, and repaired several trash picks and a tractor (thanks to this forum might I add! Appreciate it!) I got 4 leaf blowers, worked on some string trimmers, have a go kart, a chain saw, a couple generators, a couple of pressure washers, yard vacuums, and yet...
I've never experienced a bad spark plug. I really am dumbfounded. I've worked on probably 40 or so engines at this point, and never encountered a non-firing plug. the NGK ones I have all work fine, so do champions, etc.
I'm Sure this will get me a lot of hate but admittedly I don't change plugs much anymore, because like I said they just aren't ever goin bad for me. If I have a rough/bad running engine or no spark I'll put a different plug in as a test measure to see if it improves, but otherwise, I just leave them. So far, not one is bad!

IT goes like this
And is a two forked problem.

The first bit is the EPA mandating things like 0.00 % lead in exhaust.
THis means that spark plugs can no longer have a glaze on the insulator on the center electrode thus attempts at mechanical cleaning leave a trail of metal particles to make a conductve path down the side of the electrode.

Second part is the mixture of random organic solvents masquerading as petrol that gets pumped into our vehicles .
Regularly what we get is a very light fuel oil with some aromatics tossed in so it can start when the air & engine temperatures are low.
This rubbish is conductive at cylinder compression pressures and will coat and stick to the non insulated center electrode and complete the alternative path down the side of the insulator to the root of the plug rather than jumping the gap.

This is what creates the "bad out the box" syndrome.
Once a plug is wetted like this it will nt work till it gets hot enough t burn off all of the crud so that cylinder will pump unburned fuel strait into the atmosphere till either it gets really hot or you swap it for another.
So once again we have a case of the EPA making things worse in an ignorant attempt to make things way better than they need to be .

As for plugs I could not express it any better than Hammarmechanic.
The right grade is far more important than the brand.
FWIW I have Champions & NGK's in my shop + a job lot of Bosch I got for 20¢ a plug a while back
 

ILENGINE

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I use NGK or autolite and both are good in my book i never did like a champion.
I had issues with J19LM several years ago where you could install a plug in a push mower and it would run for 2-5 minutes and then quit with no fire. Replace the plug and do it again. Had about 100 plugs that did that one year. Switched to NGK after that. I have had a few like less than 5 BPMR7A also do the same thing in Stihl Chainsaws,
 

StarTech

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The only NGKs I had problem with is the CMR6H (3365). They do some strange things from no spark to one case where a hedger was dieseling but mostly misfires. I chalk that up to them being 10mm versions. They do fail enough that I keep a couple boxes on hand.

I normally don't see many bad plugs in any brand but I am low volume shop too. With this mind I do change out worn plugs but it is not because of a failure to spark.
 

Hammermechanicman

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Pretty much everything that comes through my shop gets a new plug. I probably change a hundred plugs a year that are perfectly fine. I have customers that may only put 10 to 20 hours on a push mower but want me to do full maint every year. I change out new looking air filters and plugs. Then you get the mower that looks like 500 hours of use in a dust storm and the guy says he thinks the air filter is fine.
 

bertsmobile1

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Pretty much everything that comes through my shop gets a new plug. I probably change a hundred plugs a year that are perfectly fine. I have customers that may only put 10 to 20 hours on a push mower but want me to do full maint every year. I change out new looking air filters and plugs. Then you get the mower that looks like 500 hours of use in a dust storm and the guy says he thinks the air filter is fine.
And I go the opposite way.
Just regap the old plugs & put them back if they are good.
Draw attention the the fact that I did not change the plugs cause they were still good & no use in replacing a part that does not need replacing.
After that no one questions weather some thing I replace needed replacing or not.
The $ 1.50 profit from a plug sale is not missed and quickly gets recouped in things like carb & rocker cover gaskets that are always replaced

Local mechanics are apparently renown for charging for plugs that are not replaced and at least a 1/4 of the stuff that comes in has some sort of mark on the plugs so the owner will know they were actually changed .
IT was funny when several customers who all live near each other challenged my bill because the old plugs were still there without actually checking that they had not been charged for new plugs.

As for customers that tell me a part I want to replace is fine I hand them an imdemenity certificate to sign which relieves me of any warranty claim for the repair.
To date not a single person has signed it and that is the last time they try that one on.
Down here repairs must be guaranteed for 6 months by consumer law .
 
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