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32:1 vs 50:1 jetting

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I have a 2003 CR250R 2-smoke. It has an FMF Gnarly pipe, Turbine Core SA, JD jetting kit, and V-Force 3 reed block. I ride it in the woods, not on MX tracks at all. I've been running 32:1 and would like to switch to 50:1. I've been running Bel-Ray H1R, which can be mixed at 50:1. But I'm switching to Amsoil, either Interceptor or Dominator oil. I have an Amsoil customer card and use their 10w-40 in the trans and in my street bike. Is there a general rule on how many main jet sizes to go down, for a starting point? Pilot jet reduction? Obviously, I'll have to tweak from there and maybe change the needle height, too. Thanks for any advice.

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You are going from 3% oil to 2%. One percentage point change richer in gas in the mixture.

I have always been under the impression that each main jet is about 3% difference. If it isn't I would love for someone to chime in and correct me.

Anyway, I wouldn't change a thing immediately. Jetting can be off more than that if the temperature changes 20 degrees.

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If you change premix to 50:1 you are going to run rich, but is the same if you make your jetting on winter and you leave like that on summer, you are going to run richer but nothing serious

The best way of jetting for me is with the plug,

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