Spark Plugs?

[jimbo]

I was just wondering what spark plugs you all use. I did some mods over this LONG stinkin winter. TFI , Debaffled and Caddman and more important ...chrome , and i think its time to change plugs so i can keep an eye out for signs of too lean or too rich. My oem # is NGK DPR6EA Just curious if any one is better than the other...THANKS

[refugio]

I use the same as the bike came with.....The NGK are very good plugs IMO.

[blowndodge]

I'd stay with them. Seem to stay clean in my engine and I have the TFI

[jimbo]

Thanks guys. I will stay with the oem's.

[ringadingh]

I use the NGK Iridium plugs, they are one heat range colder than stock, but work very well all the same.

[Cajunrider]

The original plugs are NGKDPR6EA-9. I went to the dealer a couple of months ago for a new set and he sold me NGKDPR7EA-9. I called the guy in parts this morning and asked if the 7's were OK. He said they are good and are 1 temperature number colder. He actually recommended them over the 6's. Any thoughts on this? I just cleaned my original plugs and put them back in. The gap was 0.034" and the insulators were mostly white to a very light tan.

[dogdoc]

I bought the same NKG plugs set gap at 0.035 and did this after 3 yrs. cost $10

[blowndodge]

If you understand the "Colder Plug" and what its for. Most think it means their Nomad will run cooler which is a mis-understanding of a plugs role. A plug is designed to burn as a certain temp to keep the plug clean.

[Cajunrider]

Brad,

I did some research on reading plugs and the difference between hot and cold plugs. NGK's explantion is that a hotter plug will contribute to detonation (pinging) because the insulator does not absorb as much heat from the combustion chamber where a colder plug does. This contributes to a hotter tip on the plug causing pre ignition or detonation. They say that the combustion chamber and engine runs cooler at the minor drawback of having to replace the plugs a little more often due to fouling. I do experience pinging quite frequently, even while using 93 octane gasoline. I will try the colder plug before the ride to Custer to see how they work out. If I still have a pinging issue, I'll install a TFI and set it to run a little richer. I worry about not being able to get 93 octane fuel traveling through the Midwest and possibly damaging my engine pulling the trailer because of constant pinging. You agree??

[dogdoc]

I agree, get the TFI and set correctly. You can then burn 87 and have NO ping and it will pull that trailer strong. You won't need a colder plug if you are going to do above mods. make sure your air side is opened up too for better flow.

[ringadingh]

I use regular 87 octane with the colder plugs, and Ive never experienced an pinging. I know that al lot of guys arn't that fortunate.
You can always carry a bottle of octane booster, for when you pick up some gas that causes the bike to ping. This way you can be assured that you won't damage the engine in any way.

[macmac]

Yes the abilty to get rid of heat is the way the center electrode is designed. You can look at similar plugs in different heat ranges and see the ceramics are different.

The spark is the same.

I sure wouldn't install new plugs for any reason other than they are eroded away, or I had a ping problem.

You can read plugs anytime you like, New is no better than 17,000 miles old.. To read a certain rpm you must retain the character of that rpm.

So to read 65 mph, you need to kill the engine at 65 mph after you have been there a while, maybe 10 mintes steady 65 mph, and clutch in to a stop. Like taking a snap shot picture.

The plugs will read that condition and or any other rpm condition you can stop the engine at..

[blowndodge]

Originally Posted by Cajunrider

Brad,

I did some research on reading plugs and the difference between hot and cold plugs. NGK's explantion is that a hotter plug will contribute to detonation (pinging) because the insulator does not absorb as much heat from the combustion chamber where a colder plug does. This contributes to a hotter tip on the plug causing pre ignition or detonation. They say that the combustion chamber and engine runs cooler at the minor drawback of having to replace the plugs a little more often due to fouling. I do experience pinging quite frequently, even while using 93 octane gasoline. I will try the colder plug before the ride to Custer to see how they work out. If I still have a pinging issue, I'll install a TFI and set it to run a little richer. I worry about not being able to get 93 octane fuel traveling through the Midwest and possibly damaging my engine pulling the trailer because of constant pinging. You agree??

I went up two steps to NGK DPR8EA last year to prove a point. Rode to Mesquite in June when it was 110. Pinged like a pig on premium all the way there. Pulled the 8's when I got home and they were dark like it was running rich.

Earlier this year I installed a TFI and now it runs so much cooler the fan has only came on one time and thats because I forced it by letting it idle for 20 minutes on a hot day!

Plugs can be a "source" of preignition but usually never is. Preignition is most caused by too much spark advance, too much compression for the grade of gas, overly lean condition so the engine "self ignites" or "diesel fires" or, has another ignition source (carbon buildup) inside in top of the pistion where it can glow and act like it's own spark plug.

Can I put a hot enough plug to cause preignition? Probably. But Kawasaki settled on the 6's for a reason. That is the correct temp to correctly burn off deposits from the plug. Our issues is the over lean condition, not the plugs. trust me on this....

[macmac]

LOL BD, I worry about my fan as it almost never comes on.. I have to just fire off the engine and let it run to make sure the fan works at all..

[blowndodge]

Mac, the TFI made THAT big a difference in engine operating temps!! I never feel heat coming up and baking my legs anymore. Rather startling difference.