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philipstjohn

Iridium Plug Info for 650R Guys

16 posts in this topic

Anyone using an Iridium plugs with a comment? I am looking for a NGK Iridium plug number for the XR650R. Anyone know it? Thanks in advance for your help...:worthy:

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Spark plugs

NGK IX Iridium 6988 BKR7EIX-11 $6.95

I run this and it is worthy of the extra money.

NGK Double Platinum 4853 PFR7B $11.71

I have tried these and they are good. No misfiring problem stock BKR7E $2.24

Split fire for XR650R

TP392B or SF392D

I ordered them for www.sparkplugs.com and they got here in 3 days!

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Just to be the devils advocate, are you going to get improved performance spending the extra cash on the Iridium plug? Most xr owners know that a properly tuned bike will start first or second kick and a regular plug will last quite literally for years. I change the plug once a year as part of my maintenance routine, the one I'm replacing always looks in great shape.

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Just to be the devils advocate, are you going to get improved performance spending the extra cash on the Iridium plug? Most xr owners know that a properly tuned bike will start first or second kick and a regular plug will last quite literally for years. I change the plug once a year as part of my maintenance routine, the one I'm replacing always looks in great shape.

I'm with Agent2 on this one. Has anyone ever done objective testing, like a dyno test, with these special plugs and seen any difference?

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I got 7k invested in my xr650r. Spending an extra few bucks for an iridium plug seems a no-brainer.

I use a Denso #5310 Iridium plug, $13. My logic is if it only once saves me from a fouled condition or provides a bit extra spark at the donut shop, with all the Harley guys watching me kick, then it was worth it.

I am like the frankster, I run iridium in all my bikes.

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I still have the original Iridium plug in my 02 CRF 450. In the long run they turn out to be cheaper then a stock plug or even a platinum jobber.

Do you guys know where iridum comes from? I didn't but just found out and I think if I told you, you would say I was wacko or something.

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I'm with Agent2 on this one. Has anyone ever done objective testing, like a dyno test, with these special plugs and seen any difference?

the only difference you'd see on a dyno test from changing a spark plug on an XR-650, would be due to the dyno variances, air density changes, etc.

you might see a difference on some ultra high compression, high horsepower vehicle, but not an XR. ;(

spent a LOOOOOT of time around dynos, and tried this myself on my Supra, and the only power differences I saw, were equal to the power differences I saw between two sets (of 3) runs I did, where nothing was changed.

I also raced a friend of mine (whom I race all the time) after I changed to an iridium plug in my 650, and the results were the same as they always were. and we did about 5 or 6 races to 100mph.

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I don't think anyone is saying there'll be a performance improvement, power-wise. What you will see, as huffa2 said, is a plug that has a much improved resistance to fouling.

The electrode on my Denso (and I assume on the other iridium plugs) is super-fine. What that does is focus the spark into a very small surface area, thereby making it a bit higher temperture, and the electrode stays carbon-free longer, particularly under rich-mixture conditions.

Harley's are renouned for fouling if you leave the enrichner (choke) out too long during warm-up. An iridium is less suseptible to fouling (yeah, my Harley's have iridium plugs, now).

I did not notice any increased power when I changed over to iridium. I did it for reliability reasons.

One last point: all plug threads should get a bit of anti-seize lube on them when you install them. Platinum or Iridium plugs particularly should be thus prepped, as they tend to be left installed in the head longer.

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I don't think anyone is saying there'll be a performance improvement, power-wise. What you will see, as huffa2 said, is a plug that has a much improved resistance to fouling.

The electrode on my Denso (and I assume on the other iridium plugs) is super-fine. What that does is focus the spark into a very small surface area, thereby making it a bit higher temperture, and the electrode stays carbon-free longer, particularly under rich-mixture conditions.

Harley's are renouned for fouling if you leave the enrichner (choke) out too long during warm-up. An iridium is less suseptible to fouling (yeah, my Harley's have iridium plugs, now).

I did not notice any increased power when I changed over to iridium. I did it for reliability reasons.

One last point: all plug threads should get a bit of anti-seize lube on them when you install them. Platinum or Iridium plugs particularly should be thus prepped, as they tend to be left installed in the head longer.

That's sort of what I thought. As a point of reference, I have had 4 XR's and XL's over the years and I'm sure I have put a large amount of miles on those bikes. Maybe as much as 60,000. In all that time I have used at most 7 or 8 plugs. I never had anything that resembling a fouled plug. Even when running sea level jetting at 10,000 feet. It was so rich that the plug got black with soot, but kept working fine.

Ok, now that I said that I'll probably foul a plug today.

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Just to be the devils advocate, are you going to get improved performance spending the extra cash on the Iridium plug? Most xr owners know that a properly tuned bike will start first or second kick and a regular plug will last quite literally for years. I change the plug once a year as part of my maintenance routine, the one I'm replacing always looks in great shape.

I agree here. I've been using the stock NKG plugs. Nothing special. I have my bike tuned very well, and the plug is always a golden brown. If the bike is tuned correctly, any plug will easily be able to ignite the fuel/air mixture.

Actually, I believe that if you do feel a power gain from a more expencive plug, that is an indication that the fuel/air mixture was not optimised to begin with.

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