SPARK PLUGS, end of life for IRIDIUM's?

FM-USA · Post by **FM-USA** » Mon Aug 10, 2015 7:34 am

I'm running on the Iridium plugs and after 178K miles, they're still firing nicely.... I think.
I've skimmed the Net for answers but have not found it.
How does one determine when Iridium plugs need changing?
OTHER THAN they stop firing when spark is present.

redial · Post by **redial** » Mon Aug 10, 2015 9:43 am

In my experience, the reasons to change plugs are:

Cracked porcelain body or other part broken;
not sparking;
electrodes worn away;
unable to remove dirt/oil/grease; and,
not hot enough to burn the fuel presented (could also be carbon buildup from poor sparking).

maintainer · Post by **maintainer** » Mon Aug 10, 2015 10:19 am

I don't know the clear cut answer but for me that would be when engine cranking & starting became noticeably slower, fuel mileage went down, or performance was diminished.

Rob H · Post by **Rob H** » Mon Aug 10, 2015 11:14 am

Not my words!

Iridium Spark Plugs | Advice & Information
Iridium is an extremely hard metallic element, related to platinum, which is thought to occur on earth primarily due to an enormous meteor impact millions of years ago. Other than it's hardness, the main property which makes Iridium attractive as an electrode material for spark plugs is its extremely high melting point (almost 2,500 deg C).

Since late in the 20th century Iridium has been used in alloy form as material of choice for construction of Spark plug and industrial igniter electrodes. Pure Iridium is difficult to work with, very brittle and does not have great electrical conductivity hence alloys are used to give the best combination of these properties. An Iridium alloy electrode is able to deliver good conductivity and extreme hardness. The result is that an Iridium electrode can be manufactured with an extremely small diameter, when compared to a traditional copper or even a platinum tipped electrode, without compromising the useful life of the electrode or spark plug. The narrow diameter concentrates the electrical charge and therefore a much lower voltage is required to jump the spark gap. This is beneficial in several ways:

A lower voltage is required, this reduces load on a vehicle's ignition system (less strain = less chance of failure)
A larger gap can be supported without increasing load on the ignition system (Larger gap = larger spark = more efficient combustion)
A more precise spark every time, delivered in the correct position and with the correct timing (More efficient combustion)
Assuming a suitable Iridium plug is available, benefits you are most likely to see are:

Improved throttle response
Improved economy (though this depends largely on how much you enjoy the improved throttle response!)
Increased plug service life (Depending on design, an Iridium plug could last up to ten times the life of a standard plug with little reduction in efficiency over the plug's lifespan)
Increased engine power (Don't expect to double your horsepower but a 1 - 3% increase is possible)
Improved (reduced) emissions.
Will an Iridium spark plug be beneficial for my particular engine?
This is very subjective. The vast majority of vehicles/engines will benefit from replacing a standard spark plug with an Iridium spark plug. Most benefit will result if:

There is a very close Iridium spark plug match for your standard spark plug (i.e. overall design is very similar)
The standard spark plug you are replacing is a basic copper plug (the Iridium plug will then be a more significant upgrade)
The engine has a large cylinder capacity and a large number of cylinders
Least benefit will be realized if:

There is no close match for your standard spark plug, it isn't worth compromising plug design purely to use an Iridium plug type.
The standard plugs are already a performance or enhanced design. Some standard (Original Equipment) plugs are Iridium or fine wire platinum types, these may already provide the ultimate performance and service life for your particular engine. Fitting an aftermarket Iridium plug may actually result in a drop in performance and service life.
Denso Iridium Spark Plug types
Denso Iridium Tough Plugs
Denso's Tough Plug design combines an ultra fine 0.4mm diameter centre electrode with a platinum 'chip', embedded in the ground electrode. High quality materials are use throughout. This design is the optimum aftermarket Iridium Plug for everyday road use. Service life is around double that of the Iridium Power type without compromising performance. Service life of over 60,000 miles is achievable for normally aspirated engines. These plugs are a great investment for modern engines where performance is an issue and considerable time is required to service or replace the plugs. We keep all popular parts in stock as well as some less commonly requested designs. The correct part for your vehicle can be identified by using our 'Advanced Search' application.

Denso Iridium Power Plugs
This is Denso's 'basic' performance Iridium spark plug range. Tried and trusted by performance enthusiasts worldwide. A traditional ground electrode is teamed with Denso's ultra fine 0.4mm Iridium alloy centre electrode to provide excellent performance. Service life for normally aspirated engines can be up to 30,000 miles but we would expect plugs to be past their best by this time, 20,000 miles is a more practical target and replacing after a shorter interval may provide greater savings in fuel economy.

There are a wide variety of designs and heat ranges from 14 (very warm) to 34 (extremely cold) in some designs. We keep the vast majority of designs and heat ranges in stock.

Denso Iridium Racing Plugs
The ultimate protection for a race or high revving engines. Denso's ultra fine 0.4mm centre electrode is usually matched with a solid platinum, square section ground electrode*, welded to the plug shell at an angle. Vibration can cause issues with ignition systems in racing engines which may rev to 20,000rpm or more. The strength of these plugs ensures that vibration does not cause any issues and the chances of plugs fracturing or melting are greatly reduced.

Supplied in an individual, protective plastic case. We keep the most commonly requested plugs for cars and bikes in stock, others are available to order.

*Note that some race parts do not have a traditional ground electrode, these are known as surface discharge plugs and remove the risk of damage to the ground electrode (as there isn't one!)

Denso OE Iridium Plugs
These plugs are equivalent to the original plugs fitted at the factory when the car is being built. Usually a 0.6mm Iridium alloy centre electrode matched to a platinum chipped ground electrode for optimum service life without compromising performance. Service life can be as much as 120,000 miles for this plug type. Denso makes the OE parts for many vehicle manufacturers and therefore their aftermarket OE Iridium plugs are the best option to replace the original factory fitted plugs (where available). If a Denso OE Iridium plug is fitted as standard we would not recommend fitting any alternative part (unless the engine is heavily modified). Most OE Iridium plugs are available from stock.

NGK Iridium Plug Types
NGK Iridium IX Plugs
NGK's basic aftermarket Iridium spark plug range, though some part numbers are recommended as standard by NGK UK. A traditional ground electrode and a 0.6mm Iridium alloy centre electrode result in an Iridium plug which offers good value for money. Though not as performance orientated as Denso's Iridium Power, Tough or Racing plugs, the IX range does provide an extended service life and improved performance over standard copper plug types. You can find a suitable Iridium IX plug by using our 'Advanced Search' application.

NGK Iridium IX spark plugs

Not all NGK racing plugs incorporate an Iridium centre electrode. Those that do will have either a standard ground electrode design, usually in nickel alloy, or a solid platinum bar ground (similar to the Denso racing design) and a 0.4mm Iridium alloy centre electrode. Like the Denso Iridium racing plugs, these parts are designed for strength whilst maintaining optimum performance. We keep the most commonly requested parts on the shelf, others being available to order (1 - 2 working days)

NGK Laserline Iridium LPG Plugs
Due to ever increasing fuel prices LPG (Liquified Petroleum Gas) conversions are becoming more commonplace in the UK and Europe. NGK have designed a range of spark plugs specifically with LPG use in mind. Part numbers range from LPG1 - LPG8, these eight different designs cover the vast majority of petrol engined vehicles in the UK and Europe. A fine Iridium centre electrode and an embedded platinum chip in the ground electrode add to the performance and service life. The use of high grade materials (superior to those of standard spark plugs) prevents contamination, abnormal erosion and wear. Initial investment cost is high but overall costs are reduced due to the extended plug service life and improved fuel economy. We keep the entire LPG range in stock.

NGK OE Iridium Plug Types
NGK manufacture OE Iridium plugs for many major motor manufacturers. Design is usually a 0.6mm diameter centre electrode and a platinum chipped ground electrode. As with Denso OE, we would not suggest or recommend replacing an OE Iridium plug with an aftermarket equivalent, design would inevitably be slightly different and this will most likely have a negative impact on ignition efficiency. We keep a good inventory of NGK OE Iridium plugs in stock at all times.

Champion Iridium Plug Types
Champion OE Automotive Iridium Plugs
Champion have produced a limited range of OE Iridium plugs for UK specification motor cars. The same applies to Champion OE Iridium plugs as to Denso and NGK OE Iridium, if it's fitted as standard we wouldn't suggest changing it. These plugs are designed to be the ideal part for a specific engine and therefore they are unlikely to be suitable for any application other than that for which they were designed. Some parts are kept in stock, others are available to order.

Champion Industrial Iridium Plugs
Champion were one of the first to realize the potential of Iridium in the manufacture of electrodes. Iridium is the ideal material for use in Industrial ignitor electrodes. The combustion conditions in engines and generators running on natural gas, methane etc are extremely harsh, wear of plugs can be extremely rapid, engines often run 24/7 and servicing is costly. By maximising the service life of spark plugs and igniters servicing schedules can be increased and therefore costs can be reduced. Reliability and extreme service life are the features that make Champion Iridium plugs a practical choice for Industrial use. Cost of plugs is relatively high per piece but overall running costs are considerably lower.

FM-USA · Post by **FM-USA** » Mon Aug 10, 2015 12:13 pm

YUP, read all that too. Still says nothing about WHAT happens when they need changing.
I just HATE to spend BIG.$$ on something that's IF'Y, I prefer to know before my money flows.

Rob H · Post by **Rob H** » Mon Aug 10, 2015 12:33 pm

It says about 120 000 miles. I think they would last longer in a wing. The engines are not high revving.
I would take them out and just have a look at the tips and see if there is any degradation.

I doubt you will need to do anything.

Rob H · Post by **Rob H** » Mon Aug 10, 2015 12:37 pm

I suppose if you had access to a scope you could compare the firing lines.

FM-USA · Post by **FM-USA** » Mon Aug 10, 2015 1:09 pm

mmm bout 20K ago I, pulled'm and Ohmed'm and were within spec.

Ya, I read that 120K also but also every application is different. ONE Wing owner said he's got 220K+ on a set. Was 'HOPING' for that, not that I'm cheap, I just like things to last.
This C.C.C. (Cheap China Crap) is becoming disgusting, anything they make lately barely lasts a month to a year.

FM-USA · Post by **FM-USA** » Sun Aug 16, 2015 6:40 pm

UPDATE
.
My Iridium plugs are still good. Well within Ohm specs.

DaProblem? E85 gas!
DAMN station didn't post the sign they got from the fuel delivery dude.
____________________________________________________________
.
I'm really surprised I didn't get crushed by that semi the other day. At a stop sign waiting for an opening when there was one I took it. Split second after starting off the bike stumbled badly and I hit the brakes. LUCKILY it was a down hill run in reverse for me and I back peddled QUICK!
This FUEL-MIXED-CORN-KRAP has got to go or we need REGULAR to be available everywhere, not just for the farmers in obscure areas.
We need Regular, non-ethKRAPanol fuel for our machines that were made for it BEFORE SOMEONE DIES!
Looks like a nationwide petition needs to be started. Problem is, this kind of petition will need fairly high 6 figures in signers.
Is there enough here?

.
I went up into CheeseLand and got REGULAR fuel today... OH MY GOOD GOD, what a difference. No stumbles, starts immediately when cold, has proper power and best of all, GOT MY NORMAL NEAR 2-UP 50 MPG BACK, whereas ethKRAPanol only gives me 32-38 MPGs.
That's a 30% loss to a 10% ethKRAPanol mixed blend. That makes no sense at all.
.

Scooter363y · Post by **Scooter363y** » Thu Nov 03, 2016 1:55 am

FM,
How about an update on those plugs? How many miles do you have on them now? How is performance?

Scooter

FM-USA · Post by **FM-USA** » Thu Nov 03, 2016 7:31 am

Scooter363y wrote:FM,
How about an update on those plugs? How many miles do you have on them now? How is performance?
Scooter

I take it you're meaning the Iridium plugs?
Haven't had an issue, still in the bike. Now that you've mentioned it, that's 14 months. With no plastic removal to pull the 2 rear ones I'll check before winter sets in.

I found a set on the Net on sale about 8-9 months ago each for $4.99?, so I have replacements. (Pays to have patience

)
Just 2 weeks earlier regular NGK's were on sale for about TWELVE BITS each (go figure). BUT there were special 'soicumstances', (the sales kid didn't know when I ordered). Oh well, my gain. They didn't loose, broke even so I'm good with that.

oldishwinger · Post by **oldishwinger** » Wed Nov 09, 2016 7:04 pm

I run iridium plugs in my asps and would not have anything else, how long do they last, well, how long is a piece of string really I've had three sets in 10 years with the new ones just put in, I've never noticed a drop off in power at any stage, I just replaced them because of the time really.

so the best I can sort of suggest if the bike is running fine then leave it be or feel free to change them if you think they may need it because of time.

old vfr · Post by **old vfr** » Tue Apr 04, 2017 11:46 pm

FWIW, Replacement intervals are given for specific models. Most Honda street bikes with OEM Iridium plugs are specified to be replaced at 16,000 miles, but I'm sure this is purely an emissions related specification. My CRV is specified at 110,000 miles.

Perhaps the "end of life" specification is that given for the Honda motocrossers and ATVs as follows:

-------------------------------------
(From the CRF450X Owner's manual, TRX500FA ATV is the same instruction)

"This motorcycle uses a spark plug that has an
iridium tip in the center electrode and a platinum
tip in the side electrode.
Be sure to observe the following when servicing
the spark plug.
• Do not clean the spark plug. If an electrode is
contaminated with accumulated objects or
dirt, replace the spark plug with a new one.
• Use only a “wire-type feeler gauge” to check
the spark plug if necessary. To prevent
damaging the iridium tip of the center
electrode and platinum tip of the side
electrode, never use a “leaf-type feeler
gauge’’.
• Do not adjust the spark plug gap. If the gap is
out of specification, replace the spark plug
with a new one.
Check the electrode for wear (rounded tip) or deposits, the
sealing gasket ... for damage, and the
insulator for cracks. Replace if you detect
them.
Check the spark plug gap using a wiretype
feeler gauge. If the gap is out of
specifications, replace the plug with a new
one.

The recommended spark plug gap is:
0.039 – 0.043 in (1.0 – 1.1 mm)
IFR8H11 (NGK) or
VK24PRZ11 (DENSO)
------------------------------------------------

I suggest that by the time the electrode wears that much, replace the plug. That's when I replace them.

FM-USA · Post by **FM-USA** » Wed Apr 05, 2017 8:37 am

I know "The Books" give specs on plugs, I'm asking how long do irridiums last.
My set came with the Wing and 160k of my miles later, are still firing fine. Unknown when the P/O installed them. I have a new set to install IF & WHEN needed.

redbug · Post by **redbug** » Wed Apr 05, 2017 9:26 am

Overheard from a Harley rider, "If it aint't broke don't Fixit "

FM-USA · Post by **FM-USA** » Wed Apr 05, 2017 11:12 am

redbug wrote:Overheard from a Harley rider, "If it aint't broke don't Fixit "

I don't know, that phrase might have come from some caveman after inventing the wheel.
"As long as that big wheel rolls, don't fix it. But is it gets smaller, re-purpose it. Skate Wheels?"

minimac · Post by **minimac** » Wed Apr 05, 2017 9:14 pm

I was taught "Any doubt? Throw them out." Over 178,000+ miles and you're worried you might be replacing them too soon? C'mon....Do you run your tires until they are bald because you want to get your moneys worth? If money is really that tight for you, I'll buy you a set of plugs!

FM-USA · Post by **FM-USA** » Thu Apr 06, 2017 7:15 am

minimac wrote:I was taught "Any doubt? Throw them out." Over 178,000+ miles and you're worried you might be replacing them too soon? C'mon....Do you run your tires until they are bald because you want to get your moneys worth? If money is really that tight for you, I'll buy you a set of plugs!

I'm afraid your analogy is a bit off.
I posted I have a set at the ready so I'm NOT worried about replacing too soon. This post isn't multi-page so it can be read from the beginning.
`
I'm not one to TOSS OUT because of doubt. "IF" there is doubt I will test 'X' first because it could possibly/probably be something else.
I don't believe in this current "Throw Away" world, "any doubt, toss it out" just feeds the corporate monster called FORCED GREED.
`
Besides, your analogy begets you buying a new Wing if anything goes wrong. Ya, I'm extreme thinking a little, but not by much if one was to think about it.
BUT HEY, if you're that generous (and rich), don't buy me a set of plugs, buy me a newest possible GL1500.

`

coolrogue1 · Post by **coolrogue1** » Wed May 17, 2017 12:08 am

FM-USA wrote:UPDATE
.
My Iridium plugs are still good. Well within Ohm specs.

DaProblem? E85 gas!
DAMN station didn't post the sign they got from the fuel delivery dude.
____________________________________________________________
.
I'm really surprised I didn't get crushed by that semi the other day. At a stop sign waiting for an opening when there was one I took it. Split second after starting off the bike stumbled badly and I hit the brakes. LUCKILY it was a down hill run in reverse for me and I back peddled QUICK!
This FUEL-MIXED-CORN-KRAP has got to go or we need REGULAR to be available everywhere, not just for the farmers in obscure areas.
We need Regular, non-ethKRAPanol fuel for our machines that were made for it BEFORE SOMEONE DIES!
Looks like a nationwide petition needs to be started. Problem is, this kind of petition will need fairly high 6 figures in signers.
Is there enough here?
.
I went up into CheeseLand and got REGULAR fuel today... OH MY GOOD GOD, what a difference. No stumbles, starts immediately when cold, has proper power and best of all, GOT MY NORMAL NEAR 2-UP 50 MPG BACK, whereas ethKRAPanol only gives me 32-38 MPGs.
That's a 30% loss to a 10% ethKRAPanol mixed blend. That makes no sense at all.
.

Just read this thread and all I can say is.....are you crazy?....E-85 gas is ONLY for vehicles marked "dual-fuel" or something to that effect. It should NEVER be used in a vehicle not designed for it's use. All E-85 pumps by law must be labeled as such and the pump handle and sometimes the hose itself MUST be yellow in color.

On the Iridium plug question, it's been answered, if you measure the gap and it's out of the tolerences given replace the plug, if the tip is "gunked up" replace the plug...If the plugs are within tolerences and work properly, then keep using them....

FM-USA · Post by **FM-USA** » Wed May 17, 2017 7:42 am

coolrogue1, The gas station did not post the required E85 sticker ON the pump before I pumped the fuel.

The station manager had the stickers but did not post BEFORE the fuel truck left. I fueled up just as the truck was packing up to leave. Luckily most of the fuel I pumped was E10, unknown how much E85 was pumped. The station mgr. had a portable hand fuel pump and removed what was in my tank and refilled.
There's no lasting effects from this incident so all is good. The fuel station owner is an old friend of mine, so I let it go.
Hope that clears up any confusion.

coolrogue1 · Post by **coolrogue1** » Wed May 17, 2017 10:26 am

FM-USA wrote:coolrogue1, The gas station did not post the required E85 sticker ON the pump before I pumped the fuel.

The station manager had the stickers but did not post BEFORE the fuel truck left. I fueled up just as the truck was packing up to leave. Luckily most of the fuel I pumped was E10, unknown how much E85 was pumped. The station mgr. had a portable hand fuel pump and removed what was in my tank and refilled.
There's no lasting effects from this incident so all is good. The fuel station owner is an old friend of mine, so I let it go.
Hope that clears up any confusion.

Sounds like there was more than just the stickers that was left undone before you pumped the fuel, but yes that clears it up....

Sam

FM-USA · Post by **FM-USA** » Wed May 17, 2017 10:53 am

Quite right. I used the phrase 'Old Friend' because of his laxness. I just stopped by to say hi and a few gallons but it'll be near never I'll stop in at that station again.

gervais · Post by **gervais** » Mon Apr 22, 2019 6:34 am

What would be the NGK Iridium part number for my Aspencade 1984???

thanks
ps i am running the standard NGK number that i saw in my owner manual

gervais

MikeB · Post by **MikeB** » Mon Apr 22, 2019 2:00 pm

I've heard it said that leaving a spark plug in place for too long can make it pretty difficult to remove.
As inexpensive as standard NGK 5129 (DPR7EA-9) spark plugs are for the GL1500, replacing them every 12,000 miles is the probably the best option. But that is just my opinion.
At less than $3.00 a plug it is hard to go wrong.

gervais · Post by **gervais** » Mon Apr 22, 2019 7:10 pm

MikeB wrote: ↑Mon Apr 22, 2019 2:00 pm I've heard it said that leaving a spark plug in place for too long can make it pretty difficult to remove.
As inexpensive as standard NGK 5129 (DPR7EA-9) spark plugs are for the GL1500, replacing them every 12,000 miles is the probably the best option. But that is just my opinion.
At less than $3.00 a plug it is hard to go wrong.

it depends Mike if the one who installed them put some oil on the tread and tight it with a REGULAR torque,,not over tight
i have seen some mecanic using air gun or 1/2 ratchet

logic should be use !!!

gervais

SPARK PLUGS, end of life for IRIDIUM's?

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