Jetting for altitude change

A reference for the PWK carbs...
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CodyShires
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Jetting for altitude change

Post by CodyShires »

Hello I'm new to the site but not to the Kdx. I've had my 2002 since 2004. The past few years I've been traveling a lot for work and haven't had much opportunity to ride. My bike was stolen while I was out here in California at the end of last year. After missing for six months I actually got it back! (I'm from a very small town, I knew it would turn up eventually, just never expected it to be in a rideable condition) I had the bike shipped to me out here in San Diego where I've completely rebuilt her. Frame sand blasted and powder coated, top and bottom end rebuild, everything is new other than the plastics. This also marks the first time the motor has been opened since 2002, never done a top end rebuild, in fact I've never even fouled a plug! A true testament to the legendary Kdx reliability..... But to get to the issue at hand I'd like to get a ballpark on where I should be for jetting. I know how to jet a bike so I'm not asking how to do it, just would like an idea on where to be for the elevation change. Where I always ride back home was around 400ft give or take a couple hundred. At that altitude I ran a 45pj and 160mj needle in second position and it was absolutely perfect. Where I'm at now we routinely ride at 4000ft and occasionally reach around 6, what do you guys think? Bike is a 2002 Kdx 220 fmf desert w/ power core2 frp milled head, 36mm bored carb, and porting done by Jeff as well. The only thing different now is I've installed the vforce3 reeds. Any help is much appreciated!
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doakley
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Re: Jetting for altitude change

Post by doakley »

With all the mods by frp why not call and discuss with Jeff? I'm sure he would have some guidelines for you.
CodyShires
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Jetting for altitude change

Post by CodyShires »

I recently had Jeff rebuild the crank and work the suspension as well. I asked him to send me the jets he thought I would need. He sent a 42pj and 152mj. I put them in yesterday and the bike doesn't want to idle. I had to turn the idle almost all the way in and if I back it off just a touch the bike dies
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Julien D
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Re: Jetting for altitude change

Post by Julien D »

I agree with the above. Reach out to FRP and discuss. A 42/152 combo should certainly not affect your idle that drastically. You may need to adjust the airscrew as well.
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