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2007 KX250 jetting

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I am finally getting lean enough on my KX250's jetting. She came with 50 pilot, 152 main, needle middle clip, air screw 1.5 turns outs. After a few steps I've gotten to 42 pilot, 148 main, needle at top clip, air screw 2 turns out. It always ran well and seemed powerful. It made so much fricken power at Vedder last weekend it was stupid. Almost too much power for the super slick conditions. It was very crisp, no sputter, an excellent ring-ding note was produced. I am in love all over again. I also switch oils from Yamalube 2R back to MC-1, sticking with 40:1.

The plug still had a fair amount of black but wasn't shinny black like before. More of a fluffy black. A step in the right direction.With only one tank run through the engine all of the Yamalube wasn't cleared from the cases so I'll ride it some more before going leaner. I don't know if the oil was a problem but I'm gonna find out.

I just can't get over how much better it was. I thought I was riding a well set up bike before. Now I see what it's supposed to be like. I've gotta be close now. I'm still hunting for that nice tan on the plug.

So now a question: Can you achieve a nice tan without sacraficing parts? I'm sick of changing plugs but not interested in replacing that habit with top-ends. I know another quick test is to see if you can hold steady rpm's at part throttle in neutral, the engine not trying to race upwards in the rev's. Perfect so far.

Note: Riding in the super tight/technical woods of British Columbia's south west, elevation at my usual spot: 1000-3000 ft. Vacation spots 3500-5500ft. I jet for my usual and live with the odd fouled plug at the vacation spots.

So far I have had many agree the Yamalube is a large contributor to fouling.

thoughts? Experiences?

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I personally believe that my bike 06 YZ250 runs better and fouls less on the Yamalube than the Klotz R50 that i'm running now so i'm going back to Yamalube.

My plug fouling problems were eliminated with the JD kit and the Yamalube at 32:1

Just my personal opinion:excuseme:

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