125-200cc 12 cr 144 jetting

To start off, I stretched my budget to get the 12 so the Lectron will have to wait. I have a stock mikuni with the Suzuki needle. Low end is a little sluggish and mid gets even more. Top end seems to be good! I have rode it 3 times so the bike now has approx 20 hrs on it, had 10 when I bought it. I run maxima 2 stroke oil at a 40:1 ratio. OK, so I took the plug out today and it is black and not the brown color it should be. Where do I need to start?

Congrats on the new steed.
What octane are you running?

Have you read some of the jetting threads in the index? try to find where it is running rich - the main first then pilot . You could also try lowering the needle - raising the clip.
Find out what your jets, needle and slide number is - that may help others.