Spark plug difference on 426

6 replies to this topic
  • beasleys

Posted August 29, 2005 - 07:51 AM


I replaced my spark plug for the first time since I have owned the bike this weekend. I got a new plug from the dealer and it was a NGK CR9E. There was no problem with my old plug just some preventative maint. Well i pulled the old plug out and it was a NGK CR7E. What is the difference if any between the 2 plugs? I used the 9E from the dealer and worked fine, just wondering for future reference. Thanks :D

  • DaveJ

Posted August 29, 2005 - 09:16 AM


The number represent a heat range, which is determined by the exposure of the ceramic cone.

Additionally, I would stick with the factory heat range unless you have a reason to run colder or hotter. And, the EK plugs (double electrodes) are better than the standard Es.



Posted August 29, 2005 - 04:07 PM


the CR7E is a hotter plug. the lower the heat range number, the hotter the plug runs.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • Slowmotion426

Posted August 29, 2005 - 08:29 PM


The NGK CR8E is what the manual calls for on my '01 YZ426F.

  • Ryan426

Posted August 14, 2010 - 06:27 PM


Sorry to open an old thread but I have a ? Hope some one can help me. My '01 426 now has a CR9E and I have a new CR8EK. My question is what does the K mean. The manual says to use CR8E.

  • grayracer513

Posted August 15, 2010 - 07:12 AM


The K indicates it is an iridium spark plug. It's the same heat range as the CR8E, but with the improvement of a precious metal electrode. The plug is less prone to fail to fire due to partial fouling, and will make the bike start more reliably. It should also last a lot longer. Perfect for your bike.

  • Ryan426

Posted August 15, 2010 - 09:13 AM


Thanks gray for the reply.

Related Content


Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.