Jun 17, 2000
Hello all,
I have raced/ridden mx most of my life and i have the
Main jetting nailed!
But lately woods riding seems to be the choice for me.
When I run a H.S. I am never on the main jet
My plug is wet and Black!
I need to nail down the 1/4 to 1/2 circuit!

Do I lean out the needle clip?
Go leaner on the entire needle size?
Go one size leaner on the pilot?
"Do" all of them, or just one of them to "Tan" my plug...
Which one is the most influentual?
Thanks to everyone in advance!

2000 cr 250
FMF gnarly
Boyseen dual stage reeds


Nov 1, 2001
Well... all of the above are options. I would start by doing one thing at a time. Is the idle pretty clean, or does it load up real quick? If its fast to load up, I'd go less pilot. If you've got a good idle, maybe lean out on the needle. You best bet is the ride and feel method, just play with it till its running good. Getting a really nice tan plug is going to be real tough under a lot of part throttle running... but if you can keep it from loading up and fouling out, and still making strong roll on power, your probably about right. Just my $.02

Mr. Clean

Nov 8, 2001
I have found that many bikes are too rich on the throttle valve cutaway. You can also lean the bike down in the throttle positions you mentioned by replacing with the next needle. Needles can be leaned for almost any throttle position if you know to change. The straight portion of the needle just above the taper is the area to change at 1/8 to about 1/4. Just increase the diameter one or two sizes. You may have to fine tune your pilot and/or the clip postion a little. I had to go three steps leaner to get it right!
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