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Advance Auto has Autolite iridium plugs on sale for $4.99 after rebate. Visit http://advanceautoparts.com/rebate for details

Also have $2 off Bosch iridium plugs.
You know, over the last 30+ years I've never used any other spark plug brand than NGK's. I do know Champion plugs suck, but I think the only other brand I had any contact with was an Autolite plug in the used lawnmower I had.

Is anyone here running anything other than NGK plugs in their bike??


Curious,
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Mine has Denso i believe. I think Im gunna put NGK's in this spring.
 

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I only use NGK plugs in all my toys. Always had good luck with them.
 

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I have Autolite (a.k.a. lawn mower)plugs in mine- all I could find in an emergency after I dropped my stock ones with 35,000 miles o onto the concrete. Now that I have NGKs (not iridium) ready to put in, I have no reason to, as the current plugs are working fine. People take spark plugs way too seriously.

And here's the flame starter (so to speak):

Platinum and Iridium plugs require a lower voltage to spark, so in stressed ignition systems (weak or failing coils or wires, turbocharging, very high rpms) specialty plugs can increase performance. Without paying attention to the plug gap in your application, however, using specialty plugs can reduce performance with a "cooler" spark. Denso has marketed their way out of this by claiming that the U-channel on the electrode creates a fireball that improves performance, but the test cases noted on their website can be explaned by weakness in the ignition systems tested.

The primary benefit of platinum and iridium plugs is in engines with reduced spark plug access- they don't have to be changed as often-- center electrodes are more robust, being specialty metals. Other than this benefit, it would require multiple iterations of standard steel, platinum, and iridium plugs with varing gaps and a high-performance ignition system to be run on a dyno to optimize a particular plug's gap for a given ignition system. The highest power spark is obtained with an old-school steel spark plug and an upgraded ignition system (coil and associated wiring in our case.)

To sum it all up- if you see a performance gain by just swapping in platinum or iridium plugs, then you are correcting a misfire (failure to spark) at high RPMs, which is fine, but my VN750 doesn't have an ignition system issue.
 

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^ bullshiit. If the plug creates a hotter spark in a weak system, it will produce a even hotter spark in a less weak system.

The Vulcans coil output is already weak compared to "high performance" systems.... Thus ANYTHING that makes a better spark is good. My bike didn't miss at higher rpms, with regular plugs or iridiums. But it did start easier and faster with iridiums.

Your post leaves out simple laws if physics. A charge between two metal posts will spark hotter if you decrease the size of the posts themselves... If you make the electrodes on a spark plug smaller you run the risk of them eroding (read as melting) faster. But if the metal you use has a melting point higher than the heat caused from the spark, you get the hotter spark without that problem.

This is the one and only reason iridium plugs are better. Their smaller center electrode creates a hotter spark (over the same distance). The "iridium" used has a real high melting point, so the tip if the electrode doesn't erode as fast.

So you get a hotter spark and a longer lasting - more consistent plug. And that in any engine is usually a good thing.
 

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Ok I'll try to keep this simple, but short may be asking too much. I HAVE used iridium plugs in my Vulcan, they were in there about 15,000 miles. I got them to try and improve hot starting, as there was nothing else wrong. I COULD NOT TELL THE LEAST BIT OF DIFFERENCE in any way. net plug change I went back to the cheaper NGKs. It still sometimes has hard start problems. I now believe this to be more in the fuel system. The NGK plugs give a nice big fat blue spark while the engine is being turned over by the starter.

While we all know the Vulcan has a weak CHARGING system, I have seen nothing to indicate it has a weak ignition system. Mine sure doesn't. Plus, it has FOUR plugs. I never understood why, but it does run better with 4 than 2. I suspect the reason for that is plug placement. None of the 4 plugs are placed in the right position for use as single plugs.

In short, I've been hearing about the iridium plugs for years now, tried them, and found no difference except for what they cost. Seafoam on the other hand..........
 

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Please get your facts straight before calling bull****. There is more energy (heat) in a spark from a spark plug that has a higher arc over voltage. Smaller, thin-wire cathodes of platinum and iridium plugs will arc-over at a lower voltage. If you are more of an applied-science person, then there are dyno runs posted online comparing different plugs and ignition systems. If your bike runs better with $12 spark plugs, that's great, but it indcates a breakdown somewhere in your ignition system, or a faulty factory design.

If you buy the U-groove argument from Denso, well, you don't need platinum to make groove in your electrode.

Here is a link to a random post with some anecdotal statements.

http://www.ducati.ms/forums/80-hall-wisdom/31417-platinum-iridium-sparkplugs.html
 

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Also read this at the link you gave:

"I have used Platinum or Iridium plugs on all my bikes for the past 5 years now and will not use standard again. I find that on changing to either platimum or Iridium the bike immediately feels much snappier in it's throttle response.

As far as the plug gap goes, I thought all plugs were supplied pre-gapped these days. Maybe it's a case of being blissfully ignorant, but my bikes run really well using the as-supplied gap on NGK Iridium plugs now so I shan't go back to conventional."

I can agree that the smaller electrode might spark with a
Lower voltage, but the coil output is the same regardless of the plug. The reason there's a spark at all is because of amount of excess electrons present. If this is say 10,000 volts, you have X number of electrons jumping the gap. They dont care what size the electrode is, they just want to jump. A smaller electrode will force the to jump closer together, making a hotter spark. Granted, it may be "smaller" in size, but my issue was with you saying it would be "colder"....
 

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Please get your facts straight before calling bull****. There is more energy (heat) in a spark from a spark plug that has a higher arc over voltage. Smaller, thin-wire cathodes of platinum and iridium plugs will arc-over at a lower voltage. If you are more of an applied-science person, then there are dyno runs posted online comparing different plugs and ignition systems. If your bike runs better with $12 spark plugs, that's great, but it indcates a breakdown somewhere in your ignition system, or a faulty factory design.

If you buy the U-groove argument from Denso, well, you don't need platinum to make groove in your electrode.

Here is a link to a random post with some anecdotal statements.

http://www.ducati.ms/forums/80-hall-wisdom/31417-platinum-iridium-sparkplugs.html
I'm keeping my Iridiums because I know the bike runs better. Your link also states his bike ran better. Also in your link the problems with the Iridiums were because the owners used the wrong gap, as stated in the link. The link says to gap Iridiums at .035 minimum. The spec for the VN750 is .036 gap, again agreeing with your link for best performance.
 

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I'm not getting into the argument with regards this is better than that, but what I have found in the last 2 weeks of working on my vn750 is that when it had standard NGK plugs in it would not start on both cylinders the rear was fine but the front would not fire up as soon as I replaced the plugs with iridiums both cylinders started firing and the bike ran a lot better and it starts first time every time now
 

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I am in total agreement that many people have had good results with platinum and iridium plugs and it is not a placebo effect. Platinum/Iridium plugs spark more reliably. I did have an issue with a dropped cylinder at idle, but I put larger pilots in the carb which fixed the problem. Don't know if iridium plugs would have helped or not.
 

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Well not going to argue over the techno babble offered by "Shazzam". I dont know him? Or his background. Is he just a Ducati head or wrench? He doesn't sound like a physicist or an electronic wizard but , again, don't know. After all this he offers no data or proof... So I say with appologies to Kelly...who just sounds to be repeating Shazzams post here... And with the knowledge that what I am about to say works both ways.....but

Its always amazing the stuff folks will believe simply because they read it somewhere on the Internet.

I admit I am no electrical expert, but I do have a fair understanding of many laws of physics. But lets just forget that and mention that alot of my family are in various "sciences" for a living. There's geologists ,computer scientists, a biologist and my own daughter is a math major and works at an observatory.
My cousin Wesley, now retired, worked for a big electronics company. He has a Masters in Electrical Engineering. He designed stuff for the space shuttle.

He was over at my house awhile back, while I still had my Vulcan. I was showing him the bike in the garage, and he picked up an empty box that had one of my NGK iridium plugs in it and said "Iridium.nice....I use them in my car" (a 900 series BMW)

My thought here is if the iridium plug was just snake oil or even just company propaganda, the one person I know that would not be fooled by it was standing there in my garage saying he used them himself. I didn't ask him why, and really even now see no reason to.

And as Gump would say.... That's all I have to say about that. ;)
 
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