Hey folks- Need some help. What does lean and what does rich refer to? Lean not enought fuel? Rich to much fuel?
I am new to the 2 stroke and need some help. I have a Scrambler 400 and the plug is black with oil. Do I adjust the air screw on the carb or adjust the oil injector?
I think on the air screw out is to lean and in is to rich, is that correct?

 

Rich is too much gas. If you are running rich, you have to put a smaller main jet in. You dont adjust the air screw or the injectors. I suggest finding someone who knows how to jet a quad and have them help you.

 

Is the plug black after you ride at low rpm levels for a while? mid? or just hi? if it is all of these then i would adjust the pilot jet, needle, and main jet

pilot- bottom end

needle- mid

main- top end

if your just getting into this then i would have somebody that knows what they are doing to do this because if it gets lean the piston will melt.