kdx hybrid jetting

Discussion for swapping a KDX motor in a MX frame...
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bike4500
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kdx hybrid jetting

Post by bike4500 »

Has anyone that used the stock kx 125 air box had to really lean there jetting out from the stock settings on there hybrid? Right now i'm at 150mj and 40pj and i still need to go leaner on the pj. Thanks in advance
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Tyl3r
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Re: kdx hybrid jetting

Post by Tyl3r »

I cant remember exactly what jets are in mine right now, but I don't think I changed the main or pilot from what I had in it when the motor was in the KDX chassis, just an air screw adjustment. 40 sounds about right thought, I think that's what I have in. Did you ride that motor/carb combo when it was in the KDX chassis? Just wondering if something else could be messing you up, like a float height adjustment, airbox boot leak, worn top end, leaky jet block gasket, etc
04/05 KX220 Hybrid all decked out
18 KTM 500 EXC-F Dual Sport/Sumo toy
24 KTM 300XC-W Cheater bike
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bufftester
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Re: kdx hybrid jetting

Post by bufftester »

Check all your boot connections. How did you account fro the difference in lip sizes between the carb and the airboot? I used the stock KX125 airbox, with an adapter cut from the KDX airboot, and no jetting changes.
bike4500
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Re: kdx hybrid jetting

Post by bike4500 »

I had my cousin machine me a ring that made the kdx carb the same size as the kx air boot. I never rode the kdx as i bought it as a basket case. I do think i'm going to get the jet block gasket and the whole motor was completely rebuilt. I was thinking that with the kx airbox more air coming in equals leaner jetting. I'm going to get at it and work on the jetting.
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Re: kdx hybrid jetting

Post by bike4500 »

ty13r Do you remember how lean you went on your main?
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bufftester
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Re: kdx hybrid jetting

Post by bufftester »

Yeah, If you had the lid off your KDX airbox the KX unit isn't flowing any more air. As long as everything is air tight you should be fine on jetting. Jet block gasket would be a good thing to check.
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Tyl3r
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Re: kdx hybrid jetting

Post by Tyl3r »

bike4500 wrote:ty13r Do you remember how lean you went on your main?
I looked all over my garage and cannot find anywhere where i have it wrote down :oops: sorry man. I'll post if I end up finding it
04/05 KX220 Hybrid all decked out
18 KTM 500 EXC-F Dual Sport/Sumo toy
24 KTM 300XC-W Cheater bike
bike4500
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Re: kdx hybrid jetting

Post by bike4500 »

thanks
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