I have added a touch of star dust to the GS. Well actually meteor dust.

Quote
Iridium is a chemical element in the periodic table that has the symbol Ir and atomic number 77. A dense, very hard, brittle, silvery-white transition metal of the platinum family, iridium is used in high strength alloys that can withstand high temperatures and occurs in natural alloys with platinum or osmium. Iridium is notable for being the most corrosion resistant element known and for its significance in the determination of the probable cause of the demise, by a meteorite strike, of the dinosaurs. It is used in high temperature apparatus, electrical contacts, and as a hardening agent for platinum.

No I'm not "Off the Planet" I just replaced my stock GS spark plugs NGK DPR8EA-9
with some NGK Iridium plugs  NGK DPR8EIX-9



As you can see the Iridium plugs have a much smaller centre (center for you yanks ) electrode. The smaller the electrodes surface area, the easier it is for the spark to jump the gap. This reduces the chance of miss firing especially with lean fuel to air ratios.

We all know the GS typically runs very lean, and that motorcycle engines don't have the strongest electrical systems, so any help you can give the system is a bonus.

The small 0.6mm electrode NGK used is made from a very special metal known as Iridium. This is because with softer, more commonly used materials like Nickel, Gold, Silver and Platinum would wear away too quickly at this small size. The standard NGK plugs centre electrode for comparison is made of Nickel and is a little bigger than 2.0 mm.

The side electrode also has its side ground away. The minimises the amount of metal over hanging the spark area, allowing the flame of ignition to spread faster and more evenly.

A more efficient spark plug in theory results in more power, better fuel economy and reduced emissions.





Now as for NOTICEABLE performance increase.... from the seat of my pants I have noticed nothing. But then again a 1-2% increase (about the maximum you could ever expect from spark plugs) would not be very easy to detect by the seat of your pants.

I did this more for the peace of mind that anything that helps to reduce misfires is a good thing!

and reduced misfires equals better acceleration and power delivery.

A side benefit is you can keep them in motorbikes for up to 32,000km / 20,000 miles! (96,000km / 60,000 miles in normally aspirated cars!)

The only draw back of these spark plugs is the price as they were 3-5 times dearer than the stock plugs. I purchased mine for $14 AUS from E-bay.

For those on a lesser budget, NGK's V-Power offer some of the performance benefits of these Iridium plugs for no additional cost over stock plugs. They do not however last as long as the Iridiums.

Hope this some what helpfull



http://www.sparkplugs.com/sparkplug411.asp
http://www.spark-plugs.co.uk/pages/technical/spark_plugs_technical.htm
http://en.wikipedia.org/wiki/Spark_plug


Now this might be marketing BS, but on this page http://www.ngkspark.com.au/pages/bulletins/T01-7.htm NGK claim the long life benefits of a 0.6mm centre electrode over the 0.4 that Nipon Denso use.

Now if performance was your ONLY consideration, then the Nippon Denso Iridium plugs might be worth investigating.

Quote
Denso's current Iridium Power product range is aimed mainly at the performance car and motorcycle markets.

Construction of NGK and Denso plugs is similar for the most part, the big difference being Denso's use of a 0.4mm Iridium tipped centre electrode - claimed to be the world's smallest production centre electrode, where NGK's IX centre electrode is 0.6mm.

As with NGK Iridium, and indeed most other spark plugs, the narrower the centre electrode is, the lower the potential difference (voltage) that is required to jump the gap between centre and ground electrodes. It follows that the Denso plug will require an even lower 'spark jump' voltage than the NGK plug.

The Denso plug also utilises a 'u-grooved' ground electrode which is claimed to aid in the production of a 'flame core' which further improves the combustion process. In theory, all the benefits offered by NGK Iridium plugs are further improved by the Denso Iridium plugs - with the exception of service life. The smaller diameter of the Denso centre electrode means that less wear can take place before the plugs' optimum service life is exceeded.

The Denso Iridium Power spark plug equivalent for the GS500 is the IX24B

Hi all

I[m using a DP8EA-9 spark plug......    its much easier to find this over here....

Do u guys think i should replace it for a iridium or a standard one?


thx a lot,
Filipe

I purchased 4 Iridium NGK plugs from BikeBandit I believe and am anxious to put them in in the Spring.  Too cold now in OH.  I have the GS500F and purchased them for my 03 Suzy Kantana 600.

Quote from: Filipe_500 on December 24, 2006, 06:11:57 AM
I'm using a DP8EA-9 spark plug...  it's much easier to find this over here...

Do u guys think i should replace it for a iridium or a standard one?

Filipe

A standard DPR8EA-9...but, how does it run with the DP8EA-9?

I recently replaced my non stock champion plugs with stock issue NKG on my 1993 GS. I've noticed that it seems to be running hotter now, it could always be my imagination. The idle also seems to be higher now 1400 rather then 1200 rpm. Since this is a spark plug post, any ideas?

-ash

Gap too close?  Make's it easier for the spark to jump across the resistance of the gap.  Kinda like advancing the ignition.

Quote from: ashman on December 24, 2006, 01:03:30 PM
I recently replaced my non stock champion plugs with stock issue NKG on my 1993 GS. I've noticed that it seems to be running hotter now, it could always be my imagination. The idle also seems to be higher now 1400 rather then 1200 rpm. Since this is a spark plug post, any ideas?

-ash

Probably actually Getting the Spark that it needs to Burn Now.Srinath will Probably Chime in and say that the Champions are better though. This is Where I would have to Disagree with Him.For the Past Many many Many years that I have Played with Motorcycles and Small Engines I have had Nothing but Problems with Champion Plugs.Yes Even Straight out of the Box.

Also If you are Running Resistor Plugs they are not Needed.If you have the Stock Spark Plug Caps on your Bike they already have the resistors Built in.Too Much Resistance will cut down on the Power of the Spark.

 That's wonderful  Info, I was think about trying Iridium spark plugs in the GS after reading a little about them in Matrix/Vibe forum, they came in my Toyota Matrix standard, and from what I've come to understand my car would not even really run without them, or if it did run it would have no performance and very likly harm the engine.

I'm running Iridiums simply because I had to mail away for new plugs and figured I might as well put in the better ones. I haven't had any problems. I don't think you're supposed to gap Iridium plugs, though.

Quote from: Filipe_500 on December 24, 2006, 06:11:57 AM
Hi all

I[m using a DP8EA-9 spark plug......    its much easier to find this over here....

Do u guys think i should replace it for a iridium or a standard one?


thx a lot,
Filipe

Using a spark plug without a resistor in theory will give you a slightly brighter spark. However NGK Australia offers the following advice:

QuoteAll modern engines require the use of resistor type spark plugs.

A resistor type spark plug is one that incorporates a 5 K ohm resistor to suppress ignition noise generated during sparking. (Radio frequency interference).

Radio frequency interference is commonly exhibited by the crackle sound coming from the car radio and there is now an Australian Standard covering R.F.I. which is considered a type of pollution.

As R.F.I. can also cause premature failure to other electronic components in a modern vehicle, it is important that resistor spark plugs are used to prevent this possibility.

NGK UK says this...

Quote
As well as reducing electrical noise for radio, television and mobile telephones etc, many modern ignition systems require resistor plugs to stop electrical noise from interfering with the vehicle's on-board electronic control units (ECUs). If non-resistor plugs are used in place of resistor ones, the result can be malfunction and in some cases immobilisation of the vehicle. Resistor spark plugs should always be fitted, therefore, where specified. NGK resistor spark plugs contain a single ceramic monolythic resistor of approximately 5000 ohms.

Because of the type and construction of the resistor (ie no springs), the problems of vibration and sudden changes in temperature that can occur with some other brands do not apply. The function of the resistor is to reduce electrical noise generated by the ignition system. The most effective place to situate a resistor in the high tension circuit is as close to the spark plug as possible.

This makes the spark plug an ideal place to house the resistor. Because the resistance value is only approximately 5000 ohms, there is no detrimental effect on engine performance, power output, vehicle emissions etc. It is also a fact that many motor sport world champions only use NGK resistor spark plugs. In nearly all cases - apart from some very old low output ignition systems - resistor spark plugs can be used in place of the non resistor versions.

Due to the Iridium plugs lower voltage requirements for a spark to jump the gap, in 99% of road usage they DO NOT  need to be gapped (they come pre-set from the factory). If you do gap an iridium plug be VERY VERY care full not to touch the Iridium Centre electrode!!!

The Resistor thing can go both ways.The Radio Interference that they speak of Occurs Mostly with AM and CB Radios.Also with running Both Resistor Caps and Resistor Plugs your Electrical System could Also Fry from Having to Push the Spark to Ground thru too Much Resistence.You'll Have 5,000 Ohms on the Plug and up to 5,000 Ohms on the Resistor in the Cap.Maybe more Depending on How Much extra Resistence builds up from Use.

Personally I doubt that a system designed to use resistor plugs, like the GS500's are would have a problem.

But like I said, in theory using a non resistor plug should improve spark some what.

Quote from: Jughead on December 24, 2006, 10:07:35 PM
The Resistor thing can go both ways.The Radio Interference that they speak of Occurs Mostly with AM and CB Radios.Also with running Both Resistor Caps and Resistor Plugs your Electrical System could Also Fry from Having to Push the Spark to Ground thru too Much Resistence.You'll Have 5,000 Ohms on the Plug and up to 5,000 Ohms on the Resistor in the Cap.Maybe more Depending on How Much extra Resistence builds up from Use.

Jughead I love your use of capitalization. Its very... new. Instead of all caps, no caps, or proper caps, you take it in a whole new direction. 

Why thanks....... I guess.I've really never noticed.I think it's a Twitch or Something.  

Champions are usually shorter life. I seem to start thinking that its getting bad in about a year. NGK's were bad right from the box. I however believe now the quality issues with NGK have been fixed. So YMMV. Literally ... 
Cool.
Srinath.

I m use also Iridium Spark , it is very good. But this alone nothing give to your bike. You need also performance exhaust and Air filter. In drag race it is very help me for high torque.But if u want use iridium spark , once week u have to drive over 8000 rpm in top speed , other wise u can burn your spark plug. This high performance spark plugs clean it self over 8000rpm.

Quote from: zeda3000 on December 25, 2006, 02:59:42 PM
I m use also Iridium Spark , it is very good. But this alone nothing give to your bike. You need also performance exhaust and Air filter. In drag race it is very help me for high torque.But if u want use iridium spark , once week u have to drive over 8000 rpm in top speed , other wise u can burn your spark plug. This high performance spark plugs clean it self over 8000rpm.

I've never heard anything like this. Care to reference it?

(subtext for non-native English speakers: I think this is bullshit, prove me wrong)

Yoo smart guy , check the below link , i think still not late for u to learn new things in your life...........


http://www.ngk-sparkplugs.jp/english/techinfo/qa/q13/index.html

Copy from NGK web site as......


Occasionally drive under high-speed conditions (approximately 80 km/h or more) to ensure spark plugs reach their self cleaning temperature.


I m racing over 2 year and this is very funny that you try to teach me what is spark plug ,

so now think who bullshit  ......

Well RPM (velocity) and temperature do clean plugs.
Now 8000 rpm that I dont know for sure, a long stroke motor with tremendous swirl velocity may clean out well much below that due to swirl velocity and what not.
A bike with 4 valves and 1 plug in the center will probably be in a pocket of dead air till you get rpms up.
The GS is likely to have decent velocity flow around the plug even lower down.
Temperature helps clean it when you shut it down. It should burn off the carbon and mixture that may have gotten slapped on it in the last few seconds of riding/idling. Else it wont restart.
Cool.
Srinath.