FMF Factory 4 jetting for a CRF250

Has anybody used the jet kit that came with the Factory 4. Im at 6,000 altitude at around 60 degrees. Right now I have a 155 main and the rest stock. Those are the stock jets.

If it runs good now it should run good with the pipe. On my Yamaha I didnt have to make any changes. My friends with Honda's didnt either. You will have to adjust your jetting for the altitude and temp but at most maybe one size main bigger for the pipe.

I didn't have to make any adjustments for my 05 CRF250R when

adding the Factory 4 exhaust. My friend went from a 40 to a 42 on

his pilot on his 04 CRF250R. The 05 already has a 42 in it. Runs great.

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