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Finnally gonna change the plugs on the 9r... any suggestions as to better plugs than the stock ngk's... not overly concerned about power increases... just looking for a cleaner burn, maybe a little more longevity...

heard about the splitfires and the titanium's never tried em figured it was all just hype, but if anyone has had some actual experience with other brands/types lemme know ...
thanks
 

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same ole same, threadjackin here & whoopin ass on the Hornets Nest in my typical PC manner :D
 

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I have a new set of NGK Iridium plugs that I picked up cheap a while back.
Noticed that the tips are really tiny vs. the regular NGKs. Mike, do you happen to know what advantage (if any) to them is. Hotter spark maybe?
Which would result in what? Or maybe they're just a gimmick.

From my experience, NGKs are the most reliable spark plugs for any kind of motor.
 

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I have no idea & won't pretend to...

What I do know is that iridium tipped plugs are very sensitive & cannot be cleaned or gapped period. If they are not in spec you throw them away & get a new one.

BTW On the RC51 we have actually verified HP gains under very controlled & scrutinized conditions by installing new plugs at intervals as small as 4000 miles. Granted the RC motor is a lot more finicky than the 919 mill, but it is interesting.
 

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Stick with the NGK or Nippon Denso that the manual recommends.
Is there any reason to pick NGK above the Denso? I looked on sparkplug.com and the Denso lists for roughly 1/2 the price of the NGK.
I just wondered if there was a reason besides the three letters...
 

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2002 Honda 919, 1976 Yamaha XT500 cafe, TC-JAG TZ250
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I have a new set of NGK Iridium plugs that I picked up cheap a while back.
Noticed that the tips are really tiny vs. the regular NGKs. Mike, do you happen to know what advantage (if any) to them is. Hotter spark maybe?
Which would result in what? Or maybe they're just a gimmick.

From my experience, NGKs are the most reliable spark plugs for any kind of motor.

The primary advantage of precious metal spark plugs is the melting temperature of the metals used. This takes advantage of a basic property of spark propogation, which is for a given amount of energy delivered to the plug, the smaller the electrode area, the greater the intensity of the spark. Having seen high speed films of tests done to find out why this is so, it is revealing to see the spark jumping away from a wide plain steel electrode -- it actually leaves the electrode over the entire tip then "bundles", or tries to form into a single narrow column before hitting the ground electrode. In this, it is only partially successful as the ground also has a fairly large area and does not present a single narrow target -- you end up with a series of small sparks twisting around and interfering with each other. With a narrow electrode, the spark jumps already bundled, so does not produce multiple paths. While it is possible to sharpen a steel electrode tip to a point, it would not last very long due to the relatively small area of the tip melting a tiny amount every time a spark jumps, eventually becoming a large ball considerably further away from the ground. With precious metal electrodes, which melt at a much higher temperature than steel, the spark doesn't heat the metal to its melting point, so they not only last considerably longer, they also maintain good spark intensity for practically their entire lives. The best plugs of this type have precious metal tips on both center and ground electrodes, making them practically eternal. As for the differences between NGK and Denso, it's strictly a matter of personal preference rather than any major advantages given similar construction. In my case, NGK gets the nod in most situations.

Rob
 

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Rob is obviously a very smart man. I wish my ADD would allow me to fully appreciate everything he has to say.
 
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