Copper vs Iridium spark plugs?

[Fabulous50s]

What is the real advantage to Iridium plugs? Simply longevity, or is the spark actually any different with the very fine tip?

Silly question, but I have a snowmobile with a Suzuki 660cc 3 cyl 4 stroke EFI engine. I'm quite sure it's a JDM small vehicle engine used in multiple applications.

This thing has 1400 miles on it, and revs in the 6,000RPM range much of the time. I've had some trouble with the factory Iridium NGK plugs cracking and causing misfires.

I'm tempted to just run cheap copper plugs and change them annually. The NGKs are almost $20 each my FLAPS.

Any opinions?

 

[proveitwithdata]

longevity.

 

[slacktide_bitog]

What is the NGK part number to cross-reference to?

Iridium is mainly for longevity, but the smaller tip is supposed to make things easier to start, too.

You can do a finer tip for copper, but you'll have a very short lifespan. NGK V-Power is an example of this..

 

[Fabulous50s]

Sorry, should have put that in NGK KR8AI

 

[JavierH19]

Copper is fine but platinum's are usually just barely more unless there's an availability issue.

 

[proveitwithdata]

forgot to add, if spark plugs could add horsepower, them iridiums would be 100 a plug at autozone. ruthenium would be 1000

 

[slacktide_bitog]

Sorry, should have put that in NGK KR8AI

Autolite has the XS4162 from their iridium powersports series.
Denso IX27B is another good choice.

Do you have any pictures of the cracked NGK plugs?

 

[fantastic]

Iridiums are an excellent value for the life you get in return.

 

[wings&wheels]

All, or most plugs are copper cored to manage heat. Standard plugs will have nickel or other less costly but durable metal for electrodes.

As far as iridium's and other quality fine wire plugs, I use them in most of the old fun fleet below and do find that the carbureted cars, especially the TR6 and the Series III, idle smoother and have less 'stumbles' on acceleration. They also seem to be less susceptible to fouling. The TR and old Rover have all of their original emission controls in place and functioning, therefore they tend to run lean at certain throttle settings, etc. Fine wire plugs, regardless of metal, should require less voltage to fire and if they add any meaningful amount of horsepower....there was a problem with whatever they replaced.

I'd stick w/ good iridiums, but curious as to what is causing the failures of the NGK's. Maybe try Denso??

 

[ammolab]

What part of the plug is “cracking”. By the tip electrode…or the upper insulation?

 

[Fabulous50s]

Iridiums are an excellent value for the life you get in return.

Well this one started misfiring at 1100 miles.

I swapped plugs around and it followed the plug. I was positive I had a clogged fuel injector, but the plug was the trouble.

 

[Fabulous50s]

Must be an internal crack. I can't see it, but the misfire followed the plug. I swapped coils, then tried plugs. I was convinced I had a clogged injector. But those were the hardest to swap around, so I went easiest first.

 

[goingplacesanddoingstuff]

I use ruthenium, which supposedly has better performance.

 

[wings&wheels]

Must be an internal crack. I can't see it, but the misfire followed the plug. I swapped coils, then tried plugs. I was convinced I had a clogged injector. But those were the hardest to swap around, so I went easiest first.

Have they been out before?? Maybe someone dropped one and ignored the old adage: 'Drop a plug once, drop it twice (in the trash)'

 

[jetman]

What is the real advantage to Iridium plugs? Simply longevity, or is the spark actually any different with the very fine tip?

Silly question, but I have a snowmobile with a Suzuki 660cc 3 cyl 4 stroke EFI engine. I'm quite sure it's a JDM small vehicle engine used in multiple applications.

This thing has 1400 miles on it, and revs in the 6,000RPM range much of the time. I've had some trouble with the factory Iridium NGK plugs cracking and causing misfires.

I'm tempted to just run cheap copper plugs and change them annually. The NGKs are almost $20 each my FLAPS.

Any opinions?

Longevity?
Copper is what Toyota put in my 07 FJ Cruiser and that is what I put in it every 50k miles.
229k trouble free miles on it now

 

[Trav]

Fine wire plugs be it Iridium, platinum, Ruthenium all require less firing voltage meaning less stress on the coil, longer life, easier starting, less fouling. Prove it to yourself, put one in any OPE engine that uses a pull start and magneto and see how easy it is to start and how long it last.

 

[y_p_w]

Copper? Plug electrodes are not copper. They're typically some sort of nickel alloy. Copper would likely corrode like crazy in that environment, as well as erode in no time.

Pretty much all spark plugs have a copper core because it's good at transferring heat.

https://www.ngk.com/what-are-copper-core-spark-plugs

Most spark plugs contain a copper core for increased conductivity, improved heat control and improved resistance to fouling.​

​

"Copper spark plugs" is a term mistakenly used for a standard or traditional plug. Due to its soft nature and low melting point, using copper as an outer material would result in a plug that only lasted minutes.​

​

A standard spark plug uses a nickel-alloy outer material fused to a copper core. Some plugs also include a coating or pad of precious metals to extend plug life. As a general rule of thumb, all spark plugs utilize a copper core, but copper is not used as an electrode material.​

 

[JeffKeryk]

I replace them somewhat early; gas is expensive here. A little better mileage goes a long way. And as others have posted, worn plugs are harder on the coils.
It ain't like the good old days when tune ups were every 12K.

 

[Soft Cars]

What is the real advantage to Iridium plugs?

They're supposed to give more room for the spark because of taking up less space.

 

[Propflux01]

Are you sure the plugs you are using are bought from a reputable source and not counterfeit?