07 WR250 jetting

I just got this bike and need some suggestions on what jets i should put in. the bike is completely stock and I am going to do all of these mods to it before i work on the carb: remove air box snorkels, Twin air powerflow kit (doesnt really increase air flow), GYTR 96db exhaust insert (flows a little better than just removing the small pipe, spark arrestor still in), remove AIS, and cut the gray wire. so basically all the free mods, and i will also put the YZ throttle stop in and do the AP mods.

I am in san diego and will be riding this bike in the so cal desert for the season, so the temps are hot like 80-100 deg. and the elevation 0-500 feet.

I am also wondering what needle i should use. i have the JD jet kit needles for an 04 wr250, so if this works what positon should i put the JD (blue) needle at? thanks

I think JD recommends the red needle for lower altitude and higher temperatures. I have seen some people using the blue needle. If you use the red, it should be 3rd from the top. That's the one I used with the JD 80 main with the mods you are doing (I have an '08 WR). I moved the clip to 4th from the top when I put an aftermarket pipe on it and left the jets the same.

ok i just ordered an 08 yz250f exhaust (stock muffler) for this bike. what would you recommend i jet this bike to with the exhaust?

What exactly are you running





Yamaha sells an AIS removal kit that comes with the jets you will need, its cheap and it works, actually for all WR's.

I highly recommend it.


Right now the bike has stock jetting, and i dont know what that is. i already installed the ais removal kit and have done the rest of the free mods. i have a good selection of jets, but since im not an expert i cant really just guess what it should be jetted to. with the yz exhaust and air box snorkels removed, what do you guys think i should jet this bike to? i ride in the so cal desert

What did you end up going with for jets? I also will be running the yz exhaust on my 07 WR. I used the recommended settings in the JD kit: #180 main, stock pilot, #40 leak jet, RED needle with clip 3rd notch down, and the THIN O-ring mod. I also am in the 0 - 500 elevation range, and have the snorkel removed.

The low end bog is gone now but the bike still seams very slow. I'm coming from a Suzuki Z400 and this bike is a dog compared to the z400. Acceleration is slow and I'm topping out at about 55mph.

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