So I have a 99 fourtrax 300 4×4, and as you might recall I rebuilt the top end about a month ago, since it smoked like crazy when I got it. Since the rebuild out runs great, no smoke at all, idles perfect, has good power throughout the entire rpm range.

Problem is that the plug is soot black, indicating a rich running condition. also doesn’t seem to be getting nearly the mileage it should. supposedly has a newer carb on it, no fuel in the air box or coming out overflow, basically no other symptoms. I have adjusted the pilot screw per the service manual, but I don’t have a tach for it so I did the best I could.

Anything else I can try our should I let sleeping dogs lie?