Spark Plugs

[roger l]

I have a question about spark plugs for a 2008 R1200R. From doing my research I know that the stock plug is a NGK DCPR8EKC. These plugs are hard to get in the US unless you want to buy them from the dealer at dealer prices. Many people are using the NGK DCPR8EKP (7415) spark plug that is basically the same spark plug except the ground electrode is bent a little different. Both of these plugs are dual ground electrode plugs. NGK also offers a DCPR8E (4339) spark plug that is identical to the original equipment spark plug EXCEPT it is a single ground electrode plug. Is a dual ground electrode spark plug better that a single ground electrode plug? If so why? Would there be a problem with putting a single ground electrode plug in the R1200R? I see from reading some of the GS forums that some people are using the NGK DCPR8EIX spark plug. This plug has a single ground electrode but is Iridium.
Any information would be great.

Thanks
Roger L

[Bob Ain't Stoppin']

If it sparks and is the right heat range, it will work. You have to know the dimensions are compatible. Keep in mind that the plug only sparks to one point when it fires. That point is determined by the condition of the plug, and by the conductivity of the air/fuel in the gap. Multi ground plugs have the advantage of having more than one opportunity to find a good spot of air with fuel in it. Lean burning engines have pockets of air with little or no fuel in them since the mixing isn't perfect.

I had fine luck with single ground AC plugs in my 1100RS. Made the bike run much better than with the stock plug.

Give it a try and let us know if you can tell the difference.

[uncle BS]

i switched to the Iridium and have 30k miles on em-- very expensive yet very good, i could actually tell the engine fired smoother... never ever had an issue with ignition and plugs are a big part of ignition. Iridium it is for me... both primary n secondary.

[roger l]

I did some more research on dual electrode spark plugs and I found the video listed below from NGK. It talks about the dual ground electrode spark plugs. The last 20 seconds of the video are very interesting. It talks about the disadvantages of the dual ground electrode and how the single tip iridium and platinum spark plugs are actually better for igniting the gas mixture.

http://www.youtube.com/watch?v=53yfHLdn41k



Roger L

[roger l]

I ended up buying the NGK DCPR8EIX (6546) Iridium spark plugs. I bought them on E-Bay for $6.25 each. I installed them tonight and took the bike for a test ride. The bike ran fine. The bike felt a little smoother but who knows. A new broom always sweeps clean.

Roger L

[klennop]

I just purchased the OEM plugs from BMW...

That is the last time I will do that because no spark plug is worth that kind of money unless it cleans the bike for me also when I am done riding it!