[JPayton]

Hello! I’ve got an 07 crf250r and it’s had about 15 hours or so of run time on a fresh rebuild, it runs great and has power but recently it’s acquired a bit of a sputter on low to mid range acceleration. I changed the plug to the suggested NGK race plug prior to this issue and it’s helped significantly with hot starting. I checked the plug yesterday and it was a little black on the end which tells me it may be a little rich. I’m looking for suggestions on how to get rid of the sputter if anyone has any info! Thanks!

[Back2-2]

You answered your own question. Sputtering and black plug is as you said = running rich. Check your jetting. You may also try raising the needle clip one position to lean the mid range fueling.