Spark Plugs


What is the average life span of a plug in our bikes?

Do they actually go bad, and how can you tell?

Is there a better plug than OEM?

How bout the OEM plug wire? (I know replacing them on other motors I have had made a diff.)



I use an NGK CR8EIX Iridium plug in my 426. I use Iridium's in my street bike, and have noticed improved cold starting and longer plug life. I only have a couple of rides on my 426 since fitting the Iridium, so to be honest haven't noticed any difference yet.

Have you ever herd of a CR8EIS? team shogun yamaha uses them in there YZ250F and there YZ450F.they claim that the power up's on there bikes are mainly the plug and yosh pipe.So ther must be something to this plug.I checked at cycle gear and they are checking on it for me :)

I changed my CR8e once in riding probably 15 + hours

Since I have had the bike I have replaced the plug 4 times no reason other then I felt it was time.

I normally changed every ride, but that is when a plug was 99cents at kregan auto and Champion was a good plug

So if the last time I changed the plug was maybe 6 or 7 rides ago (maybe 180-200 miles) should I be putting in a new one? I do notice an occasional minor sputter when part throttle (1/4) almost like plug is fouling, but seems to go away if I blast a straight or two.

I changed mine after 800 miles. I have a Trail Tech computer. It really didn't need to be changed. The bike really runs no different after the change.

I installed the dsp thing I just wanted to see if there would be any kind of change. It seems to start a lot better. It wasn't hard to start before but it just seems to want to come to life now. Don't know if it's the new plug or the power now.

Either way I still run the factory recommend plug with no problems.

If your are diligent about your jetting it will last all year on a four stroke dirt bike. I am on my third plug but I have wasted a couple trying to figure out my jetting. I have never tried cleaning a plug to get extra life. Some people will do anything to save a buck or two.

Have never changed mine :)

Has anyone changed the plug to a different heat range on their bike to componsate for altitude?

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