iridium spark plugs

[steveg]

worth the extra over standard?

I normally change std plugs every 16k , hoping for 25 k from iridium plugs ?

Any one used iridium plugs on sv / last a long time ?

Cheers Steve

I've no experience of them on an SV (but would be interested to hear the experiences of people who've tried them), but general consensus seems to be they are alright for 100K miles, provided they don't become fouled. If this is true, it seems they'd be worthwhile the extra cost given the longevity of them, particularly on bikes like the 2 plug SVs. I suppose if you were prepared to risk not checking them for fouling (only investigating if you noticed a problem) at the service intervals other than valve clearances where you'd have them out anyway, it'd save a bit of time too.

Can anyone in the know confirm if there's any real grounds for claims that they appreciably reduce vibrations in the bike due to smoother/more consistent combustion, or is it emporer's new clothes syndrome?

I carnt see how they would recuce vibrations unless something was wrong anyways?

I understand them to be better suited to large temp variations and fuel quality. Otherwise for what it costs why not just change them every year?

If you use your bike all year round there are some benefits.

I don not change plugs on my own bikes down to mileage, I change them depending on there condition and function.

I put some Iridium plugs in my 01 SV at 12k. Had the valves checked at just over 17k and the plugs are still in very good condition.Like new

Im just gonna keep em in to see how much life i can get out of them....

I have them in the GS and it helped cold starting, only been in a year probably 1000 miles.

Not bothered if they last longer when all said an done £20 every now and again isn't going to break the bank.

[embee]

The technology behind them is one of the few cases where it isn't just snake oil.

The iridium (or formerly platinum) enables the centre electrode to be made much smaller diameter than previously without eroding away too quickly.

The purpose of the smaller diameter is to ensure the spark occurs at the exact same position every cycle (with "traditional" plugs the spark wanders round the edge of the electrode) and to be as exposed as possible to the mixture. This achieves the most consistent initiation of combustion, which minimises cycle to cycle variability. This is desirable for a variety of reasons, thermal, mechanical and chemical to some extent.

The by-products of this are that less enrichment is generally required for good cold starting, the loads on the ignition system are reduced (less voltage is required for a spark to occur with the small electrode), and the combustion is more tolerant of mixture variations often encountered especially with carburettors during transients, tipping-in after overrun for example.

In practice whether you'll notice any real running differences depends on how well the engine is maintained/set-up and running generally, and how sensitive you are to subtle effects. Different engines vary in their response, all are different depending on how well the combustion system was developed in the first place.

Certainly in a 2 cyl bike the on-cost of iridium plugs is fairly trivial and I'd say just fit them. The service life will be several times that of "conventional" plugs. It depends what sort of use the bike sees, but let's say start thinking 30k miles as a ballpark. You could probably double that if it gets an easy time.

I fit them in everything I have.

[northwind]

I use them too... I don't feel any performance difference between fresh iridium and standard plugs, but they last longer, they give better damp starting in my experience, they're very tolerant of bad mixtures (which is handy if you're a bodger like me and jetting by trial and error, or you're running a compromised setup, though obviously it's better to fix it). And they stay fresh for longer- I just compared a 12000 mile old set with a new set, and I can't really tell any difference. Try that with the OEM NGKs and you'll almost certainly be able to tell which is which.

I don't exactly consider them a performance mod, more a non-performance-avoidance mod

got my iridium plugs from sparkplugs.com or sumthing similar, £15 delivered. Cheap and came within 2 days........

try ebay £12.30 next day brill have them on all my pass bikes