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Winter Jetting - KTM 300XC-W

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My Current Jetting Settings

The temperatures are going to be around the 20's to 30's F (maybe cooler when I head up north to try out the ice tires). I figure I need to go from the 162 main to the 165 main.

My question is really regarding the needle. I have a JD jet kit with the red needle in. The clip position is 4th from the top. Should I bring it down a notch or 2? This is really the only area I'm not sure about so some guidance would be nice.

Dropping the needle (highest clip) is leaner than the bottom clip (raising the needle) right?

Thanks!

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Ok. So would a 40 to 50 degree temperature decrease require me to raise the needle (lower the clip from the 4th to the 3rd)? I'm not sure how much this change in temperature would effect jetting. I know the colder it is, the richer you need to jet, but not sure how far I should adjust for this change.

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Dropping the needle (highest clip) is leaner than the bottom clip (raising the needle) right?

Thanks!

You are correct with your statement......

How is it presently running in the mid range throttle setting.?.this is what your needle controls....

Main jet is for WOT....

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I put the 165 main in today. The JD jet kit recommended it for temps below 45. Took it for a little test. Mid range seems pretty good. I'm not really sure how to tell though, but there isn't any major mid range bog so I think I'm pretty good there.

I don't think the red needle on the 4th clip would be to lean would it? Then again that's what I ran in the summer.

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Generally you change the needle clip for every 2-3 main jet sizes. If you are only going one richer on the main I would leave the needle or go one clip max.

If you are using your jetting from summer as your baseline I would suggest 2-3 mains up, one clip down and one bigger pilot, especially if you're thinking ice racing.

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Elevation? this will make a difference as well.

Yes it does...Without jetting change,

As you increase altitude your engine will run richer..

Decrease altitude, it will run leaner...

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I'm around 1000 feet. I just fired it up today. It's running like crap! It was about 45 degress yesterday, today is about 30. It's the mid range that's having the issues which makes sense. I'm going to go to the blue needle like the JD jetting kit says to richen it up.

The 165 is 3 sizes richer than before. I don't have a bigger pilot, but the 38 is in. It runs good until you just get off the pilot.

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I just rode it a little more. It's running very strange as if it's way too rich. After acceleration it will almost stall. It's smoking like crazy and there's spooge shooting out the muffler. It's almost like I can't clear it out.

This doesn't make sense. It should be running lean with the cooler temps. I think I'm going to pull the carb out give it a good cleaning and change the needle to richen it up one notch.

Yesturday it was running like a champ and I was happy. Today it's barely running. 15 degrees can't make this happen can it?

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