Iridium spark plugs?

[Bassmatt]

Who uses these and what is your bikes manufacturerz recommendations on replacement intervals.
My new Suzuki apparently requires new ones every 12000 kms!
Sounds fucken ridiculous to me but happy to be told otherwise.

[neels]

12k sounds more like standard spark plug replacement interval.

The iridium plugs in my merc are supposedly good for 100k, mind you there are 12 of the fuckers so you wouldn't want to be doing it too often.

[speedpro]

My Toyota Blade has them. Replacement interval is 100,000Km. Good job as it is a mission to get to the back set.

[Bassmatt]

12k sounds more like standard spark plug replacement interval.

The iridium plugs in my merc are supposedly good for 100k, mind you there are 12 of the fuckers so you wouldn't want to be doing it too often.

Thank god they aren't standard plugs, they'd want them replaced once a month.
I'm seeing 100000 ks mentioned alot online but ois all to do with cars. I suppose with bikes revving higher they will wear quicker. My last bike had them, pretty sure replacement interval was 40000ks.

[Katman]

Thank god they aren't standard plugs, they'd want them replaced once a month.
I'm seeing 100000 ks mentioned alot online but ois all to do with cars. I suppose with bikes revving higher they will wear quicker. My last bike had them, pretty sure replacement interval was 40000ks.

Most motorcycles (before the advent of cam position sensors) use a wasted spark ignition system which means that the spark plug fires twice as often as it would in a car.

You should certainly be able to get 40,000 kms out of iridium plugs in a motorcycle though.

[caspernz]

Who uses these and what is your bikes manufacturerz recommendations on replacement intervals.
My new Suzuki apparently requires new ones every 12000 kms!
Sounds fucken ridiculous to me but happy to be told otherwise.

Check your manual and you'll probably find 12,000 is the interval for standard plugs, with the iridium ones being due around the 100,000 km mark or so.

[Hitcher]

The biggest risk with fitting iridium spark plugs are enthusiastic mechanics who replace them at the same intervals as standard plugs.

[jellywrestler]

The biggest risk with fitting iridium spark plugs are enthusiastic mechanics who replace them at the same intervals as standard plugs.

and them seizing in as they have been left a long time...

[Blackbird]

Same distance recommendation for my Street Triple and Blackbird - probably lots of ass-covering by manufacturers. However, the "guru" Blackbird parts supplier in the UK told me there was no need to change them below 40k. Changed them at this interval and they looked visually perfect.

[caspernz]

Ha, well whaddayaknow? Checked my Busa manual and the last service invoice, and yup 12,000 km change interval for plugs. Oh well, $26 a pop isn't cheap but then neither is owning a bike overall...:shutup:

Different story for my cars though, standard has a short change interval and iridium runs much longer...just soooo boring to drive a car though innit?

[Trade_nancy]

No 1 son has a Honda VTR1000 - service manual stipulates Iridium plug and a replace at 18,000km. We just replaced them at 43,000km and they were still OK - but showing signs of age...it was their time.

[AllanB]

Standard plugs in the Hornet 900 with 24,000 km change intervals. They came out looking sweet at 24 too.

Suzukis aye ...........

[nzspokes]

Ha, well whaddayaknow? Checked my Busa manual and the last service invoice, and yup 12,000 km change interval for plugs. Oh well, $26 a pop isn't cheap but then neither is owning a bike overall...:shutup:

Different story for my cars though, standard has a short change interval and iridium runs much longer...just soooo boring to drive a car though innit?

Have read somewhere that a standard plug gives more power, proven on a dyno. Has a better flame path or something. Was ages ago I read it. Iridium last longer but is not as powerful.

Not sure how true this was but there you go.

[jellywrestler]

No 1 son has a Honda VTR1000 - service manual stipulates Iridium plug and a replace at 18,000km. We just replaced them at 43,000km and they were still OK - but showing signs of age...it was their time.

so just how do you know they're OK? a lot of people think a plug is fine when hooked up to sparkplug outside the motor and it sparks, reality is can the naked eye tell the difference between a good and a not so good spark and of course, once in service the conditions turbulance etc inside a motor is a bit different from outside in thin air.

[Trade_nancy]

so just how do you know they're OK? a lot of people think a plug is fine when hooked up to sparkplug outside the motor and it sparks, reality is can the naked eye tell the difference between a good and a not so good spark and of course, once in service the conditions turbulance etc inside a motor is a bit different from outside in thin air.

I don't. We didn't. That's why they were out and new ones in. Agree with you...

[Motu]

Most motorcycles (before the advent of cam position sensors) use a wasted spark ignition system which means that the spark plug fires twice as often as it would in a car.

Hillman Hunter? Waste spark was the norm in cars '90's, 2000's, mostly COP now. If you are using plat or iridium with waste spark you need double plat or iridium - one plug jumps from centre to earth, the other earth to centre, so that one that jumps from the earth electrode is going to wear faster. If they are single fine wire that is why the shorter life - pointless, go double.

[Oakie]

Have read somewhere that a standard plug gives more power, proven on a dyno. Has a better flame path or something. Was ages ago I read it. Iridium last longer but is not as powerful.

Not sure how true this was but there you go.

Just changed iridiums for standard plugs two weeks ago and the bike is going noticably better than at any time in the last 18 months.

[Erelyes]

I've anecdotally heard that coppers give a better spark (or are more forgiving of a weak igniter) than iridiums or platinums as well. Better conductivity or some such.

[Black Knight]

You cant "read" em like a standard plug

[Shaun Harris]

Who uses these and what is your bikes manufacturerz recommendations on replacement intervals.
My new Suzuki apparently requires new ones every 12000 kms!
Sounds fucken ridiculous to me but happy to be told otherwise.



That is simple bullshit, to aid there dealer network with sales, same as all brands

[speedpro]

Shaun is on to it.
Much of the rest of the replies are to be taken with a grain of salt. Iridium plugs have lower voltage requirements for a spark given the finer tips. This will result in a more regular spark even in adverse conditions such as a lean spot in the maps or very high speed and a drop in voltage due to ignition limitations. Some have a fine tip on the earth strap as well. The ceramic will colour up just like any other plug ceramic. Given the durability of the materials used in the spark gap I have no problem believing they would be good for 100,000km in a car and possibly some lesser distance in a bike.
New plugs that replace worn plugs could easily improve performance, even plain standard plugs versus flash Iridium or other fine wire types. Personally I have dynoed a bike with fresh fuel, plugs, filter, etc, and at the end I fitted new plugs and gained 2 horsepower, 95hp to 97hp. This was a repeatable gain and the "old" plugs looked fine and there was no indication of a problem with them apart from the gain with the new plugs.

[PistonBlown]

When I fitted them on my bike was told minimum of 45k between changes (standard sparks are 15k). So 3 times the life of the standard ones is probably a rough guide.

[husaberg]

The idea of the super expensive plugs being in a low tuned road bike over a predetermined milage is mainly based on meeting emissions standards.
But if performance has suffered replace them they are not really that expensive.

[LBD]

Spark plug life and electrode erosion is directly related to how often it fire... Cruise around at 2000rpm and your plugs will last 4 times longer than if you were screaming around at 8000 rpm....:rolleyes:

[neels]

Spark plug life and electrode erosion is directly related to how often it fire... Cruise around at 2000rpm and your plugs will last 4 times longer than if you were screaming around at 8000 rpm....:rolleyes:
Assuming you're not in the same gear of course, otherwise they'll fire the same number of times and you'll just get there in 1/4 of the time.

[Laava]

When I fitted iridium plugs, I noticed that it no longer seems to be revving as high. I used to be doing 4500rpm at 100kmh but now, thanks to iridium plugs, it has dropped down to 3800rpm.

FYI I had them fitted professionally at Ichiban Moto

[Laava]

Check your manual and you'll probably find 12,000 is the interval for standard plugs, with the iridium ones being due around the 100,000 km mark or so.

No, he is right, mine is the same and further to that, they are only available from suzuki.

[Big Dog]

When I fitted iridium plugs, I noticed that it no longer seems to be revving as high. I used to be doing 4500rpm at 100kmh but now, thanks to iridium plugs, it has dropped down to 3800rpm.

FYI I had them fitted professionally at Ichiban Moto
I might be wrong but I always thought revs were a fixed ratio of speed unless the gearing ratio changed?
E.g the piston does the same number of cycles to the same number of tyre rotations aiming the same gearing ratio?

A drop off 700rpm would be more akin to going up one more gear or equivalent sprocket change.

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[nzspokes]

I might be wrong but I always thought revs were a fixed ratio of speed unless the gearing ratio changed?
E.g the piston does the same number of cycles to the same number of tyre rotations aiming the same gearing ratio?

A drop off 700rpm would be more akin to going up one more gear or equivalent sprocket change.

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Ichiban Moto is never wrong.

[Laava]

What NZspokes said.

[Big Dog]

I'll read that as your instrumentation was wrong and they fixed it free of charge while they were at it.

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[Laava]

I'll read that as your instrumentation was wrong and they fixed it free of charge while they were at it.

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Haha, something like that Matt.

http://www.youtube.com/watch?v=mhMvtw5BoRE&sns=em

[malcy25]

I was disappointed my wife's 2001 Corolla needed to change the original iridium plugs after a measly 204000 Kim's when a miss fire set in. It may have been the 80 thou plug gap though.....

[imdying]

I was disappointed my wife's 2001 Corolla needed to change the original iridium plugs after a measly 204000 Kim's when a miss fire set in. It may have been the 80 thou plug gap though.....You think that's bad, my wife's Golf only managed 127,000km. Me raping the turbo foot flat finally did them in :devil2: