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guys please help

evrything in my crf250x 2006 model is stock except for the yoshimura muffler (muffler only) no airbox or ccc mods.



current jettings

main jet 158
pilot jet 42
needle 5th clip position (red)
fuel screw 1 1/2 turn

altitude
sea level to 3000


my problem
spark plug has a black color ( i thnk this is to rich)

is there something wrong on my jettings?


thanks
alvin

Yes.

You must open your airbox. You have added fuel, without adding additional airflow.

~

what if i dont want to open the airbox? any suggestion on the jettings.

thanks

Why not open the air box? its easy, and everybodys doing it..

hello agent s

i decided to cut my airbox now, do i need to change / removed this parts? for my crf 250x 2006.

air cleaner
removed backfire screen
removed smog pump


current jettings

mainjet 158
pilot jet 42
needles 5th (red)
fuel screw 1 1/2


do i need rejet or change my main jet , change the clip position of the needles and adjust the fuel screw?


sea level to 3000 ft

thanks

alvin

Just stay with the recommended settings JD recommends Alvin, and open that airbox per the instructions.
Then just ride it and see how it runs, most likely great. A liitle rich won't hurt a thing either. Doug