The dealer can make adjustments within a certain range. It isn't like the old days when we could fully adjust them, but it does seem to help. I have had other newer 2 strokes adjusted by my dealer and it made a noticeable difference.
Unfortunately I don't have any maruyama dealers within about a hundred miles of where I live so I'm pretty much on my own with this. I ordered it online.
Ill pull the carb off when I have time see if it has a plugged adjustment screw somewhere like some other carburetors I've had.