HEADS UP!!!

Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0
Wiz636

Sparkplug heat range.

5 posts in this topic

Has anybody tried a different heat range sparkplug? I know how picky 2T's can be with this but I have never messed around with it on a thumper. Does it make much difference with the hotter temp of a 4T?

Share this post


Link to post
Share on other sites
What are you trying to accomplish?

I think he's trying to get more out of his YZ so he can keep up with me :busted:

Actually he needs to slow it down a little but seriously I think the thought of changing a spark plug vs. jetting at the change of seasons or temperatures that we have here in the NW might prove to be a more efficient use of our time... The jury is still out in terms of what a hotter or cooler range of plug will do, something about absorbtion of heat and whether or not that can have enuf effect on the bike running richer or leaner :banghead:

Share this post


Link to post
Share on other sites

Don pretty much said it...I'm trying to figure out how to beat him for a change...I'm sick of looking at the finish sheet that says 1st #930, 2nd #636.

In seriousness I'm not really trying to specifically accomplish anything...I'm simply trying to gain knowledge and was wondering if anybody in here has tried using a different plug in their 450 and if it made any real difference in performance, or if it would affect jetting, etc. I'm rather ignorant on the subject of spark plugs and figured that with all the knowledge in here somebody would know something. Even though I'm not necessarily trying to fix anything I wanted to ask.

Share this post


Link to post
Share on other sites

It has no effect on the mixture, or the engine's preference for richer/leaner AF ratios, or even how hot or cold the engine runs (with one exception).

The plug heat range is a measure of how quickly the heat at the electrode is carried away, and how hot the porcelain insulator stays while in operation. If it's too cold, the plug will not become hot enough to burn away the oil and fuel deposits that form on it, and it will quickly carbon up or wet foul. If it's too hot, the electrode itself will become damaged. In extreme cases, the plug can become hot enough to become a secondary ignition source, causing pre-ignition, which can cause detonation, and with that, heating and engine damage.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0