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
08YZ450Derek

08 YZ450F plug

6 posts in this topic

What is the plug supposed to look like on a properly jetted 450? Since the weather warming up, my plug color is off white color, with no residue. Its very clean with 2 hours on the plug.

Am I too lean? Jetting is stock, only mod is a ride eng. fuel screw. What jetting should I be running at 500ft, 70-80 degree weather? Only have a RS-2 slip on for mods. Thanks!!

Share this post


Link to post
Share on other sites
What is the plug supposed to look like on a properly jetted 450? Since the weather warming up, my plug color is off white color, with no residue. Its very clean with 2 hours on the plug.

Am I too lean? Jetting is stock, only mod is a ride eng. fuel screw. What jetting should I be running at 500ft, 70-80 degree weather? Only have a RS-2 slip on for mods. Thanks!!

it sounds like your running a lil lean. 1 up on the main jet and 1 down on the clip for the needle

Share this post


Link to post
Share on other sites

If you are running unleaded gas, the plug should look about as you described it; smoky white. It is the lead in leaded fuel that gives color to plugs. With unleaded reading plugs provides no meaningful information.

Share this post


Link to post
Share on other sites

Thanks Greyracer, It runs good at the track. I just pull the plug after every ride and replace them. I do save them to compare, but its looking all smoky white and clean. No residue (soot) and the bike runs great, just have to adjust the screw to weather differences. Always a pleasure to get good feedback for my Q's. Thanks again!:thumbsup:

Share this post


Link to post
Share on other sites
I just pull the plug after every ride and replace them.
Wow. First four stroke?

I change my plug whenever I can't remember when I put the last one in. Seems to be something like once a year. The last one I replaced looked new.

As far as jetting goes, look through this:

http://www.thumpertalk.com/forum/showthread.php?p=2881699#post2881699

Share this post


Link to post
Share on other sites

Yeah, first 4 stroke. Maybe I should leave the plug alone, the bike starts 1st or 2nd kick cold right now. Hot its like 1 kick, w/ hot start. It sounds like my jetting should be okay, the bike pulls good on the track. I do have to clutch it in the corners to keep the power in the meaty area though. Feels soft off the bottom (compared to my 98 KX250) even added a 50T rear.

Otherwise I am trying to stay off the clutch so much. First practice I was revving it out, and the clutch was fading. So I stopped doing that and now I try to roll on the power and let it build. Love this bike though, suspension works really great and I am 220lbs! I might need to play with the clickers, I have it set up MXA specs. Any thoughts?

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